TECHNICAL FIELD
[0001] The present invention relates to the processing of images in a virtually set-up game
space (hereinbelow called "virtual space") (hereinbelow called "virtual images");
in particular, it relates to image processing for a game whereby the movement of a
virtual model that is set up in virtual space (for example called a "character") on
a screen can be represented more realistically. This image processing technique is
suitable in particular for 3D video games machines.
BACKGROUND ART
[0002] Due to the development of computer graphics (CG) technologies, it has become possible
to represent a virtual space (also called "virtual world") that is set up in virtual
fashion three-dimensionally and in real time. This is the technical field of video
games machines: these have been developed in recent years and incorporate a central
processing unit (CPU) capable of high speed computation and a video display processor
(VDP) and enable such computer graphics technologies to be utilised at high speed
and in economical fashion.
[0003] In such a video games machine, the content of game play changes continually depending
on the actions of the user (also called the game player or player), so the objects
that are displayed have to be moved freely at high speed in virtual space. To this
end, usually a model constituting an object to be displayed (for example a character)
is constituted of a set of polygonal fragments called polygons of triangular or quadrilateral
shape, and the movement of such models is displayed by simultaneously altering the
spatial position of these polygons.
[0004] Also, when specified portions or faces of objects to be displayed such as the arms
or legs of characters were to be moved simultaneously, a polygon data group consisting
of an assembly of a plurality of polygons was taken as a unit and a spatial position
was given to each polygon data group, so that the specified portions or faces could
be moved simultaneously.
[0005] In recent years, so-called 3D (three-dimensional) games have attracted attention
in the market, in which a character is made up of polygons and an image is represented
on a monitor in which the movement of the character in virtual space is captured from
a virtual viewpoint; simulations of fights between a plurality of warriors are particularly
popular (for example, "virtual Fighter" (trade mark) made by Sega Enterprises Limited).
In such a fighting simulation game, a player rapidly operates a stick or pad or button
attached to a controller to make a warrior represented on the screen perform actions
in accordance with commands determined by operation of the stick etc. The movements
of the warrior are called "motion" and data in order to implement such motion is acquired
using the "motion capture" technique. This data is then processed, if need be, and
is utilised as final motion data in a 3D video games machine. In such a video game,
in order to raise the product value, it is desirable to represent the movement of
the character more realistically. More specifically, this consists in for example
adding more varieties of movement whilst approaching very closely to the actions of
an actual warrior. However, since the anticipated movements of a character extend
over a very wide range of possibilities, there are many problems that still need improvement
in order to achieve such an objective. Of course, consideration has been given to
for example compiling beforehand all the desired motion data and storing this in memory
and obtaining characteristic expressions in order to get such motion, but the problem
is that a large amount of data is required for this, which is impossible to process
in real time.
[0006] A chief aim of the present invention is therefore to provide an image processing
technique for games whereby the amount of calculation and/or the amount of data required
for image processing can be greatly reduced and whereby the movement of the character
on the screen can be expressed more in real time and more realistically.
[0007] First specific aspects of a problem that was experienced in conventional video games
machines from the point of view of this object are as follows.
A1. In a 3D video game, since the image on the two-dimensional screen from the virtual
viewpoint is represented by performing a projection conversion, it is difficult to
move the warrior in the depth direction of the screen (z direction of virtual space)
i.e. in the direction of the player's gaze, so no consideration at all was given to
enabling a warrior to walk around other warriors. To improve such movement around
the characters is therefore a first specific aim of the present invention.
A2. With a conventional 3D video games machine, there was the problem that, since
the images were displayed from a virtual viewpoint, if a structure such as a wall
was arranged in virtual space in a position such as to screen the warrior, display
was effected with the character blocked out. Accordingly, a further specific aim of
the present invention is to effect display in which this situation that the character
is blocked out by a structure is improved.
A3. In a conventional video games machine, the method was adopted of generating the
motion of the character sequentially using for example a spline function, or the method
of effecting reproduction of predetermined patterns in sequential frames. However,
with the conventional video games machine, this motion was fixed, so it was not possible
to correct the motion to match the movement of a character on the other side etc.
Accordingly, a further specific aim of the present invention is to enable such motion
correction to be performed.
DISCLOSURE OF THE INVENTION
[0008] A chief aim of the present invention is to provide from various viewpoints techniques
for the processing of images for games whereby movement of characters on a screen
can be represented in more real-time fashion and more realistically by greatly reducing
the amount of computation and/or amount of data required for the image processing.
[0009] In a first aspect of the present invention, there is provided an image processing
device for combat type games, the device being arranged: i) to set up in virtual space
a first model being controlled by a player and a second controlled model, and said
first model and said second model combat each other; and ii) to control these models
such that they move in prescribed directions in the virtual space and to cause display
means to display images of this virtual space from a virtual viewpoint; said device
comprising means for image processing whereby the execution of a prescribed motion
operation, while the game is in progress, by a player controlling the first model
causes a virtual attractive force to be set up to act between said first model and
a second model and to cause said first model automatically to move around said second
model being a centre of the virtual attractive force.
[0010] In an embodiment, the image processing means is further operable so that an amount
of frictional force which is applied to the models is varied according to whether
the models are moving or whether they are stationary.
[0011] In an embodiment, the image processing means is further operable so that a projection
image of the models is displayed matching the surface shape of a stage on which the
models are placed.
[0012] In an embodiment, the image processing means is further operable so that a determination
is performed of overlap of the field of view created by the virtual viewpoint with
respect to the model which is the subject of display and another model which is not
set as the subject of display, and, if the result of this determination is affirmative,
the other model is not displayed.
[0013] In an embodiment, the image processing means is further operable so that, with respect
to the end-point of a predetermined movement track of the model, a target point is
set up different from this end-point and the movement track is interpolated such that
the end-point coincides with this target point.
[0014] In an embodiment, the image processing means is further operable so that a difference
of level at which the model is positioned in the virtual space is found and the action
which is applied to this model is interpolated in accordance with this level difference.
[0015] In a second aspect of the invention there is provided a games device including an
image processing device according to the first aspect.
[0016] An embodiment of the games device further comprises input means for controlling the
movement of the models, said input means including direction key(s) for specifying
the direction of action of a model in question vertically or horizontally, said image
processing means being operable to execute image processing in response to operation
of the direction key(s) such as to effect automatic circular movement of the model.
[0017] In a third aspect of the invention there is provided a recording medium on which
is recorded an image processing program adapted to control the operation of a games
device in the playing of a combat type game so as to: i) set up in virtual space a
first model being controlled by a player and a second controlled model, wherein said
first model and said second model combat each other; and ii) control these models
such that they move in prescribed directions in the virtual space and to cause display
means to display images of this virtual space from a virtual viewpoint; and to perform
image processing whereby the execution of a prescribed motion operation, while the
game is in progress, by a player controlling the first model causes a virtual attractive
force to be set up to act between said first model and a second model and to cause
said first model automatically to move around said second model being a centre of
the virtual attractive force.
[0018] By means of the above aspects, the movement of the model such as a character that
is arranged in virtual space can be displayed more realistically. Specifically, images
whereby one model moves around another model can be easily generated. Furthermore,
the condition of the stage on which the model is placed can be reflected in the movement
of the model. Furthermore, unevenness of the stage can be reflected accurately and
in a simple manner in the projection image of the model. Furthermore, even if a structural
object is a wall arranged in virtual space at a position which would screen the model,
display can be effected without the model being screened. Also, versatile movement
of the model can be represented in a reliable manner since it is possible to correct
motion of the model by matching it to movement etc. of the other model. Furthermore,
more realistic images can be generated since it is possible to take into account level
differences between models.
[0019] An embodiment of the invention will now be described by way of example with reference
to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
Fig. 1 is a block diagram of a video games machine constituting an image processing
device according to an embodiment of the present invention;
Fig. 2 is a flow chart showing the main processing in a first embodiment;
Fig. 3 is a perspective view showing circular movement of a character in circular
movement processing;
Fig. 4 is a detailed flow chart of circular movement processing;
Fig. 5 is a diagram illustrating circular movement in virtual space;
Fig. 6 is a perspective view corresponding to a condition of completion of circular
movement;
Fig. 7 is a diagram of the principles of virtual frictional processing;
Fig. 8 is a detailed flow chart of virtual frictional processing;
Fig. 9 is a diagram of the principles of projection display processing;
Fig. 10 is a diagram of the principles of intersection determination processing;
Fig. 11 is a detailed flow chart of intersection determination processing;
Fig. 12 is a xz plane view of a structural object approximated by an inscribed circle;
Fig. 13 is a diagram illustrating the principles of a specific example of intersection
determination processing;
Fig. 14 is a diagram illustrating the principles of another specific example of intersection
determination processing;
Fig. 15 is a diagram illustrating the principles of a mode of approximating a structural
object shaped as a wall;
Fig. 16 is a perspective view illustrating a standard mode of character motion;
Fig. 17 is a perspective view illustrating an interpolated mode of character motion;
Fig. 18 is a conceptual diagram illustrating the track of movement of a character
produced using a spline function;
Fig. 19 is a flow chart illustrating an operation for character motion processing
control;
Fig. 20 is a diagram illustrating a condition in which there is a level difference
between two characters;
Fig. 21 is a flow chart illustrating processing of character level difference;
Fig. 22 is a flow chart given in explanation of time flow of such processing;
Fig. 23 is a diagram illustrating a condition in which level difference processing
has been performed;
Fig. 24 is a photograph illustrating a front view of an example of a human-like character;
Fig. 25 is a photograph showing a second example thereof;
Fig. 26 is a front view of a control pad to a larger scale;
Fig. 27 is a diagram illustrating file structure for a combining technique;
Fig. 28 is a flow chart for the deployment of the combining technique;
Fig. 29 is a screen front view illustrating a screen displayed by a combining technique
processing step;
Fig. 30 is a front view displaying another screen displayed by this processing step;
Fig. 31 is a front view displaying another screen displayed by this processing step;
Fig. 32 is a front view displaying another screen displayed by this processing step;
and
Fig. 33 is a front view displaying another screen displayed by this processing step.
Description of the hardware
[0021] Fig. 1 is a block diagram of this video games machine. Respective image generation
and processing No. 1 to No. 6, to be described, are executed by this video games machine.
[0022] This video games machine comprises: a CPU block 10 that performs control of the device
as a whole, a video block 11 that performs display control of the game screen, a sound
block 12 that generates effects sounds etc., and a subsystem 13 that performs reading
of a CD-ROM.
[0023] CPU block 10 comprises an SCU (System Control Unit) 100, main CPU 101, RAM 102, ROM
103, sub CPU 104, and CPU bus 105 etc. This block is the heart of the image processing
device of the present invention. Main CPU 101 incorporates a DSP (Digital Signal Processor),
which executes computer programs at high speed. RAM 102 stores polygon data of various
types that are sent to it from subsystem 13 that reads the CD-ROM, and is also employed
as a work area of the main CPU 101.
[0024] ROM 103 stores an initial program for initial processing in the initial condition
of the device. SCU 100 governs the transfer of data that is performed through bus
105, 106 and 107. Also, SCU 100 incorporates a DMA controller that sends the image
data required during running of a game to VRAM in video block 11.
[0025] Control pad 2b functions as means for information input by the user and is equipped
with various buttons needed for operation. Sub CPU 104 is called an SMPC (System Manager
& Peripheral Controller) and has the function of collecting peripheral data from controller
2b in accordance with requests from main CPU 101.
[0026] Main CPU 101 performs processing such as movement of an image displayed on a display
in accordance with peripheral data sent to it from sub CPU 104. Sub CPU 104 identifies
the peripheral equipment that is connected to connector 2a (terminal of the main unit)
and collects peripheral data in accordance with the communication system corresponding
to the type of peripheral equipment that has thus been identified.
[0027] Video block 11 acts as means for figure generation and comprises a VDP (Video Display
Processor) 120 for generating an image displayed using polygons and a VDP 130 that
performs image synthesis, shaded surface processing, and clipping for the background
image.
[0028] It is connected to VDP 121 and frame buffers 122, 123.
[0029] When an image to be displayed on the display is generated in virtual space, the polygon
data necessary for display are sent from CPU 101 through SCU 100 to VDP 120 and are
written to VRAM 121. The polygon data written in VRAM 121 are stored in image-drawing
frame buffer 121 or 123 as image-drawing data including colour information of 16 bits
or 8 bits per pixel. The image-drawing data that are stored are sent to VDP 130. Main
CPU 101 supplies control information to control image drawing through SCU 100 to VDP
130. VDP 130 controls the image-drawing data in accordance with this control information.
[0030] VDP 130 is connected to VRAM 131 and comprises a scroll function whereby the entire
display screen is shifted vertically or horizontally or is rotated and a priority
function (Z sort or Z buffer) that determines the order of display of polygons. VDP
130 outputs image-drawing data through memory 132 to encoder 160.
[0031] Image-drawing data output to encoder 160 is converted to video-signal format and
is then subjected to D/A conversion and displayed on monitor device 5. An image is
displayed on monitor device 5 based on this video signal.
[0032] Sound block 12 comprises a DSP 140 that performs audio synthesis by the PCM system
or FM system and a CPU 141 that controls DSP 140. The audio data generated by DSP
140 is output to two speakers 5a or 5b by D/A converter 170 after conversion to a
two-channel signal. Subsystem 13 includes a CD-ROM drive etc. and is equipped with
a function of reading application software supplied by a recording medium such as
a CD-ROM and a generating video etc.
[0033] The processing performed by an image generating device as described above will now
be described. Fig. 2 is a flow chart showing the main processing executed by CPU block
10. The following are executed in sequence: circular movement processing S200 for
moving a character in a circle virtual friction processing step S202, display of a
shadow on the ground when there is a difference of level (S204) i.e. projection display
processing of a character, intersection determination processing (S206), character
motion processing control (S208), and character level difference processing (S210).
Processing which is not essential is not performed but is shifted to subsequent processing.
The content of each processing is described in detail below.
Circular movement processing:
[0034] In general terms, the effect of this processing is as follows. When a direction key
26b (also see Fig. 26) formed with a + on control pad 2b, to be described, is operated
to the left or the right in the Figure, the character (warrior) 30 that is operated
by this direction key (see Fig. 3) is moved in the vertical or horizontal direction
in virtual space. In circular motion processing mode, a virtual centripetal force
(force directed to the other side's character is applied between a warrior 30 operated
by the player and a warrior 32 operated by the other side, causing processing 30 to
be executed whereby warrior 30 of the player automatically goes round (circular motion)
the other side's warrior. The details of this processing will now be described with
reference to the flow chart of Fig. 4. In step 400, a determination is made (determination
1) as to whether the circular motion processing mode has been entered or not. A circular
motion request is deemed to have been made if the player has performed a prescribed
operation. This may be for example pressing of a prescribed button on the controller
(pad 2b). Next, by for example reading the amount of operation in the left/right direction
in the drawing of the direction key 26b of Fig. 26, the position of the player's warrior
and the other side's warrior are detected and the direction that the other side's
warrior presents with respect to the player's warrior is calculated (step 402).
[0035] Next, an angle in this direction is applied to the player's warrior 30 and virtual
centripetal force towards the other side's warrior is applied to this warrior (step
404). Considered physically, this centripetal force is equivalent to an attractive
force acting between the two objects.
[0036] If the x co-ordinate and z co-ordinate of the other side's warrior are respectively
taken as (exp, ezp), and the x co-ordinate and z co-ordinate on the other side's warrior
are respectively taken as (mxp, mzp), the direction of the other side's warrior 32,
as described above, is calculated from: arctan (exp - mxp, ezp - mzp). For convenience,
the y-direction co-ordinate i.e. the height direction of the warriors on both sides
is neglected in this calculation.
[0037] As a result, circular motion in virtual space is produced (step 406) in accordance
with the speed in the horizontal direction produced by the transverse direction key
and the centripetal force. By means of this circular motion, the player's warrior
30 is made to move around the other player's warrior 32 whilst facing the other player's
warrior. Fig. 5 is a conceptual diagram seen from above in virtual space of this circular
movement, in which a warrior 30 performs circular movement from condition 1 through
condition 2 and condition 3 to condition 4. Fig. 3 described above is an image in
virtual space according to condition 1 displayed from a prescribed viewpoint, being
the image displayed on monitor 5 described above (see Fig. 1). Fig. 6 is an image
like that of Fig. 3 relating to condition 4.
[0038] Consequently, with the circular movement processing described, a single character
is given a virtual centripetal force, so the player, simply by operating direction
key 26b of Fig. 26 in the horizontal direction in the drawing, can easily apply a
circular movement to character 30. For example, movement whereby warrior 30 which
[the player] is himself operating moves around the other side's warrior 32 as described
above can easily be implemented.
Virtual friction processing:
[0039] The effect of this processing is that the movement of the character is made more
varied by altering the slippage in the movement of the character depending on the
slope of the ground surface and the frictional force acting on the character in accordance
with the nature of the ground surface, and applying dynamic friction when the character
is moving and static friction when the character is not moving.
[0040] First of all, Fig. 7 shows a cross-section of the ground surface in virtual space.
As shown in Fig. 8, the amount of slippage is calculated as follows from the slope
of the ground surface in step 800.

where
i is a prescribed constant
v is a unit normal vector expressing the slope of the ground surface and
g is the acceleration due to gravity.
[0041] As shown in Fig. 7(1), the unit normal vector is a normal vector with respect to
the tangential direction to the ground surface. When the angle (8) that this normal
unit vector makes to the co-ordinate axis (x axis) in virtual space gets large, a
larger amount of sliding (acceleration) tending to descend along the sloping ground
surface is applied to a character who is on this ground surface.
[0042] Next, in step 802, a determination is made as to whether the character (warrior)
is moving or not. This is done for example from the point of view of the player by
determining whether or not the direction key for controlling movement of the warrior
is being operated (determination 1).
[0043] If the character is moving, dynamic friction is applied; if the character is not
moving, static friction is applied (steps 804, 806). The friction (= dv/dt) itself
is calculated as follows.


where M is the weight
v is the frictional speed (speed of the object after calculation)
v' is the speed of the object
µ is the coefficient of friction
S is the ground-contacting area of the character (constant)
g is the acceleration due to gravity (constant)
θ is the angle of the ground surface
T = µ.S
[0044] The dynamic friction and static friction are determined by applying prescribed processing
to the friction (or coefficient of friction) obtained by this expression. The static
friction has a larger value than the dynamic friction. This friction changes depending
on the angle of the ground surface, the friction being smaller as the slope of the
ground surface is increased.
[0045] Next the attributes of the ground surface are determined. That is, it is determined
whether the surface on which the character is grounded is for example a water location
or a sandy location. These attributes are applied virtually beforehand to each ground
surface. For example, the amount of friction calculated in the case of a sandy location
is taken to be doubled and the amount of friction in the case of a water location
is taken to be tripled. This is then reflected (step 810) so as to subtract this frictional
force from the amount of slippage that was previously calculated.
[0046] Thanks to this processing, static friction or dynamic friction is constantly applied
to the character, so once a character has stopped it will not readily move off again,
but once it has started moving it becomes easier to move. Also, the movement characteristics
of the character can be altered depending on the attributes of the ground. By this
means, movement of a character can be represented very realistically.
[0047] Display of shadow on to a ground surface having a level difference: As shown in Fig.
9, the effect of this processing is that, when there is irregularity 91 of the ground
surface 90 on which character 91 is standing, the shadow (projected image) of the
character can be represented by a simpler calculation whilst applying irregularity
to this ground surface. An outline of this processing is shown in Fig. 9. 92 in this
Figure is a virtual reference line of height 0 and 96 is a parallel light source at
infinite distance. This character is constituted of a set of objects such as head,
breast, abdomen, hips and legs etc. Each object is created by a plurality of polygons.
yG in the drawing is the distance from the base line to the ground surface where the
character is standing and y1... yn are the distances from each object to the base
line. This processing is calculated using the following expression.

where E'(x',y',z') are the co-ordinates of the shadow.
E(x,y,z) are the co-ordinates of the character and
Ms is the matrix (matrix expression) for converting the shadow co-ordinates to the
world co-ordinate system.
[0048] This Ms is given as follows.

Mu is a conversion matrix for converting the co-ordinates of the character to the
world co-ordinate system of Fig. 9.
Tyg is a parallel movement matrix for producing parallel movement from the ground
surface on which the character is standing up to the base line.
Pn is a conversion matrix for slantwise projection of the character on to the base
line.
Tyn is a matrix for effecting parallel movement of the slantwise projected shadow
to the ground-contacting point of each object (i.e. the ground surface where each
object is located).
Tsn is a parallel movement matrix for effecting parallel movement of each object with
respect to the origin of the world co-ordinate system.
Rn is a matrix for rotating shadow polygons in accordance with the slope of the ground.
[0049] This processing is carried out by the following steps.
Processing step 1: Human-like character 91 for creating a shadow is subjected to parallel
movement from the ground surface to base line of height 0; then
Processing step 2: This human-like polygon set 91 is projected slantwise on to reference
line 94 using parallel light source 96; then
Processing step 3: The slantwise projected objects are respectively moved in parallel
for each object with width y1... yn as far as the ground surface; then
Processing step 4: Each object is moved in parallel from the position of the world
co-ordinate system up to the origin of this system; then
Processing step 5: Each object is rotated in accordance with the respective angle
of the ground surface; and finally
Processing step 6: Parallel movement is performed to return the objects that have
been moved to the origin by processing step 4 to their original co-ordinate system.
[0050] Consequently, by this processing, if there is irregularity in ground surface 90,
the projected image of a character can be displayed in a simple manner on ground surface
90 incorporating such irregularity in a manner matching this irregularity.
Intersection determination processing:
[0051] Fig. 10 is a xz plan view showing the region of the field-of-view of a virtual camera
that picks up two characters, for example warriors facing each other (character 1,
character 2). An image as shown in Fig. 3 already described is displayed by this virtual
camera (viewpoint). In this processing, when this field-of-view region is overlaid
by virtual structural objects other than the warriors, such as walls or buildings
that screen the field-of-view region, arrangements are made not to display some or
all of such structural objects. In Fig. 10, while structural objects 100, 102 screen
the field-of-view region from the viewpoint to the character, structural object 104
does not obstruct the region of the former, notwithstanding that, depending on the
viewpoint, it is in the displayed region. In this case, image generation or image
processing is performed to delete structural objects 102 and 104. Fig. 11 is a flowchart
showing this processing. In this processing, in order to speed up and facilitate the
determination of whether or not such structural objects overlay the field-of-view
region, the determination is performed in the xz co-ordinate plane, and objects having
thickness are approximated by circles. Fig. 12 is a xz plan view showing how such
a structural object is approximated by an inscribed circle.
[0052] In Fig. 11, step 110 is the processing to determine whether or not this approximation
circle overlays the field-of-view region. Fig. 13 is a conceptual view of the determination
performed in this step. The determination as to whether a given approximation circle
having radius t of centre point T is overlying or not is performed by the following
processing for all the sides constituting the triangular region corresponding to the
field-of-view region from the viewpoint to characters 1 and 2. In the following description,
vector L, vector R and vector T are the vectors to L, R and T from a prescribed origin.
Point L and point R are set sequentially for the respective vertices of each side
of the triangle.
[Mathematical expression 1]
[Mathematical expression 2]
[0054] 
cx is the x component of vector c
cy is the y component of vector c
rx is the x component of vector r
ry is the y component of vector r
[0055] From the definition of the inner product,
[Mathematical expression 3]
[0056] 

where
[Mathematical expression 4]
[0057] 
[0058] If the centre T of the approximation circle is within the positive region of straight
line TR (if T is outside the inside of the triangle), if
[Mathematical expression 5]
[0059] 
the circle is independent with respect to the region within the triangle i.e. it
does not overly this region; if
[Mathematical expression 6]
[0060] 
or

if point T is in the positive region of straight line LR, the circle is independent
with respect to the region.
[0061] In step 110, if the approximation circle does not overly the internal region of the
triangle, processing is performed (step 111) such that this structural object is not
displayed; if it does not overly this, processing advances to the next step (step
112). The effect of the next processing is to perform a determination as to whether
there is overlapping in respect of a structural object such as a wall where this structural
object has length in a fixed direction. This processing is performed as follows as
shown in Fig. 14. For a structural object that can be approximated as a straight line
TS, a determination is made as to the intersection (a type of overlap) of this straight
line and the triangular region. The following processing is performed for all sides
constituting this triangular region. If the function for determining the positional
relationship of the straight line LR and an arbitrary point P is taken to be F1 (P),
[Mathematical expression 7]
[0063] If the function for determining the positional relationship of straight line ST and
an arbitrary point P is taken to be F2 (P),
[Mathematical expression 8]
[0065] If F1 (S).F1(S) < 0 and F2 (S).F2(S) < 0, it is determined that straight line TS
intersects straight line LR.
[0066] If this intersection is denied, processing shifts to step 114 and the determination
is made to whether there is overlap with the approximation circle. The reason for
this is as follows. If the straight line TS described above enters fully within the
region of the triangle, the result of the overlap decision is negative and the wall-shaped
structural object would be displayed.
[0067] Accordingly, a small circle 150 corresponding to the thickness of the wall as shown
in Fig. 15 is associated with this straight line TS and a determination of overlapping
is performed in respect of this small circle in the same way as in step 110. As a
result, if this approximation circle enters the region of the triangle, even if straight
line TS enters completely into the triangular region and the determination made in
step 112 is that there is no overlap, it is concluded that overlap does take place
and processing shifts to step 111.
[0068] By such processing, it can be arranged that structural objects such as walls, fences,
or screens in the field-of-view region from the virtual camera to the character to
be displayed are not displayed. However, if, as shown in Fig. 10, this structural
object such as a wall projects beyond this field-of-view region as shown at 104, this
structural object is still displayed. By the above processing, character display can
be effected in the most suitable manner without the character being hidden by unnecessary
structural objects. Of course, when the character in question is absent, such structural
objects are displayed as normally. As the approximation circle, a circumscribed circle
could be employed as shown in Fig. 12 instead of an inscribed circle.
Character motion processing control:
[0069] The effect of this processing is to form interpolation such that the final position
of a single motion is matched to a target point, when it is desired to effect display
in series from a single motion without linkage of other motions.
[0070] Fig. 16 shows a series of steps of motion of a single character; the steps are shown
whereby a human-like character (warrior) 160 delivers blows using arm section 160A
to another warrior by operation of pad 2b by the player.
[0071] This action of the arm part is displayed on the monitor by calculation by means of
a well-known spline function (in particular, a third-order spline function). If now
at this point it is assumed that this arm part 160A is moving towards the breast part
of the other warrior, and, at a certain time point, the other warrior moves in the
y direction (for example, suddenly stoops), from the point of view of the player,
it is very difficult to suddenly change the track of the moving arm to downwards as
in Fig. 17 and also if CPU block 10 simply attempts to do this, the movement of the
arm can easily become unnatural.
[0072] Accordingly, a link region is provided in the vicinity of the termination of the
spline track alteration process of the motion that is currently being executed, and
interpolation such as applying a new spline function is performed in this link region
such that the terminal point of the initial spline track becomes a target point in
another position.
[0073] This will now be described with reference to the drawings. As shown in Fig. 18(1),
the fist 180A that is at the tip of the arm part of the warrior of Fig. 16 is moving
along a track 180 determined by a spline function. Fig. 18(2) shows the track 180
obtained by this spline function; fist 180A moves from the starting point of this
track until it reaches the end point and then returns to the starting point.
[0074] Let us now assume that fist 180A is moving from the starting point of spline function
track 180 towards its end point. Let us assume that, in this process, due for example
to a change in the behaviour of the other warrior, the need arises to alter the initial
end point to a target point.
[0075] Accordingly, at the time point where the position 180A of a fist is in the link region,
CPU block 10 corrects the function in this region such that it terminates at the target
point. This interpolation is performed for example as follows. Of course, this could
also be achieved by suitably altering the degree and/or coefficient of the spline
function in the link region. As a result, the motion shown in Fig. 16 is automatically
interpolated to the motion shown in Fig. 17, and the motion in the link region can
thereby be represented more smoothly. It should be noted that, for convenience in
illustration, the vertical axis in Fig. 18 (2) shows only the amount of movement in
the y axis direction. In accordance with the general conventions of three-dimensional
video games, the x axis is given in the transverse direction when looking at the monitor
screen, the y axis is given in the height direction, and the z axis is given in the
depth direction i.e. the direction perpendicular to the screen.
[0076] The link region (link time) is appropriately set up by means of a group of a plurality
of frames comprising an end frame. Also, interpolated motion of the entire arm is
effected by applying similar processing for the objects other than the fist, namely
the upper arm part and lower arm part. The interpolated co-ordinates in the link region
are set by means of the following characteristic expression:

[0077] Fig. 19 is a flow chart given in explanation of the above processing; in step 190,
a determination is made as to whether a motion movement command has been generated
by operation of pad 26b by the player. In step 192, a determination is made as to
whether a target point whose co-ordinates are different from the end point has been
set. In step 194, the selected motion is reproduced. In step 196, if the result of
this determination is positive, the link time is calculated and processing shifts
to step 194, in which the motion interpolated during this link time is reproduced.
In step 198, a determination is made as to whether or not the current frame is the
end frame of the motion series and, if it is the end frame, processing returns to
the main routine; if the end frame has not yet been reached, processing returns to
step 192.
[0078] In this process, the link frames constituting the link time represent 0.1 of the
maximum number of frames of the motion (number of frames from the start frame of Fig.
18(2) to the end frame); if the link frames exceed 10, [their number] is fixed at
10. The number of link frames should be in the range of at least 1 to 1/2 of the maximum
number of frames. If the link frames are too long, the original movement of the motion
is lost; on the other hand, if they are too short, interpolation becomes abrupt and
smoothness of the motion is lost.
[0079] The following benefits are achieved by this processing. When, as in a video games
device, the controller is operated in order to rapidly operate a character such as
a warrior appearing on the game screen, varied movements of the character are continuously
reproduced. At a time point when a series of motions is reproduced, even though [the
player] tries to alter the motion to match rapid actions of the other character, so
long as the motion itself is fixed, this is difficult. However, if motion is interpolated
as described above, the motion matching the movements of the other character for example
can be reproduced in a varied manner, making the motion more realistic. Usually, such
interpolation is extremely difficult for a user to perform and conventional video
games devices are particularly ill-constructed to performing such interpolation.
[0080] It should be noted that, while this processing has been described taking as an example
the case where the motion was calculated using a spline function, this processing
could be applied to pattern change systems in which a predetermined pattern is sequentially
reproduced. In such cases, it may be arranged to reproduce a corrected pattern in
the link region.
Character level difference processing:
[0081] The effect of this processing is to display a desired image in which this level difference
is corrected when there is a mutual level difference between a character (warrior)
and the ground. For example, as shown in Fig. 20, when there is a level difference
between two warriors 200, 202 that are facing each other, it is unrealistic if punching
from a warrior 200 to a warrior who is on a higher level is performed horizontally.
Accordingly, this processing is designed to perform the assault from warrior 200 directed
in the higher direction, correcting for this level difference (see Fig. 23).
[0082] In this processing, as shown in Fig. 21, in step 2100, a determination is made as
to whether this level difference needs to be corrected. Such a determination "correction
required" is made if an attack request (command) for assault using arms or legs from
one warrior to another warrior is generated in respect of mutually facing warriors
for example as in the drawing.
[0083] If the result of this determination is negative, next, processing returns to the
main routine. On the other hand, if the result of this determination is positive,
further, in step 2102, a collision determination is performed between the character
and ground i.e. to establish whether the other warrior is standing on the ground;
if the result of this is positive, character level difference processing is deemed
to be necessary, and processing shifts to the next step. If this determination leads
to a negative result, the routine in the Figure is terminated.
[0084] Next, in step 2104, the distance from the ground on which the character controlled
by the player is standing to the aforementioned character is calculated. The same
calculation is performed for the other character also. Next, in step 2106, the value
of this result is compared with a prescribed value, and, if the range of the prescribed
value is exceeded, processing is performed to keep the difference relating to this
distance within this range.
[0085] Specifically, if we let the height of a warrior operated by one player be (my) and
the height of a warrior operated by another player or operated automatically by a
prescribed program by the image processing device itself be (ey), the difference (diff1)
between these two is (my - ey). An evaluation is then performed as to whether for
example diff1 is within the range -0.15 ≤ diff1 ≤ 0.15, and, if diff1 exceeds this
range, a diff1 smaller than this range is taken as being -0.15 and a diff1 greater
than this range is taken as being 0.15, while a diff1 within this range is directly
determined as (diff2) without modification. The reasons for carrying out this correction
on diff1 will be described later.
[0086] In the next step 2110, diff2 is divided by the time (number of frames) for which
attacking force is generated and the result is taken as "result 1"; the result obtained
by dividing diff2 by the time from generation of the attacking force until hardening
is dissolved is taken as "result 2". This will be described using Fig. 22. Fig. 22
shows the flow of an attacking move (kick, punch or jump etc. executed by the warrior);
this is as follows in respect of the flow of frames (flow of time) for each time 1,
2... 5.
1: commencement of the move (frame number 0)
2: attacking force generated (frame number 1 to frame number 3)
3: attacking force dissipated (frame number 3 to frame number 4)
4: hardening time (this is a time in which commands for other attacking moves are
not accepted and may be from 0 to 4 frames)
5: end of the move (from frame number 0 to 5)
[0087] "Result 1" described above is therefore: (diff2) / 2 and "result 2" is (diff2) /
(4-2). These values are of course set and stored in a prescribed work RAM region.
The characteristic shown in Fig. 22 is predetermined for each move. Result 1 is a
value corresponding to the rate of change of each frame until attacking force is generated
and result 2 is a value corresponding to the rate of change of each frame until hardening
is dissolved.
[0088] Next, the co-ordinates whereby the hands and/or feet etc. move when a move is executed
are determined for each requested move in step 2112. These co-ordinate values are
determined beforehand under the assumption that there is no difference of level with
respect to the other character. This co-ordinate (leaf) is taken as "result 3". This
leaf is determined in accordance with the spatial co-ordinate position of the hand
or foot when a move is executed by a function fat for returning the leaf. The processing
when an attacking move is executed is described below with reference to the following
and subsequent steps.
[0089] After a move has been generated, in step 2114, detection is carried out to ascertain
the serial number of the frame to which the currently displayed frame corresponds.
In the next step 2116, it is determined whether or not this frame is a frame prior
to generation of attacking force. In the Figure, it is determined that frames up to
frame 1 are frames prior to generation of attacking force.
[0090] Next, if the result of this determination in step 2116 is positive, in step 2118,
this "result 1" and the frame number are multiplied and the result of this calculation
is added to the leaf of the step 2112 as a difference. Using this result, the shape
of the body of the warrior is then recalculated using the value etc. obtained by adding
this difference to the lease
1, using the known inverse kinematic technique (see for example "Dynamics And Control
Of Robots", compiled by the System Control Information Association, by T Arimoto,
published by Asakura Shoten, 5.2 Reverse kinetics (page 132 ~)).
[0091] In step 2116 already described, if it is determined that [the frame] is a frame subsequent
to that in which attacking force is generated, in step 2200, the current frame number
("2 or 3") in the Figure, is subtracted from the frame number ("4" in the Figure)
at which hardening is dissolved, and processing shifts to the step where this frame
number is multiplied by result 2.
[0092] As a result, as shown in Fig. 23, by step 2118, a punch is executed from the warrior
200 which the player himself controls towards the other warrior 202, with a height
in which the level difference of the warriors is compensated; the arm that executed
this punch is then returned to its original position whilst effecting level compensation,
whether the punch hit its target or not.
[0093] With the processing that has been described, image processing is executed that reflects
the difference in level of the two warriors, so an attack (punch or kick) that is
performed by a single warrior is carried out to a warrior in a higher location and
images matching the current situation of the actual attack can thereby be provided.
Consequently, even without storing beforehand in memory motion in respect of a warrior
in a higher position, image processing between one character and another character
can be implemented in a condition reflecting the level difference between the characters.
Incidentally, the reason why diff1 is corrected is as follows. If such correction
were not carried out, when there is a large level difference between the two warriors,
in an extreme case, the assault from one warrior to another warrior could be directed
in the direction at right angles with respect to the ground, which would itself be
unnatural.
[0094] It should be noted that, although in the explanation of the various processes described
above, the example of a video game was taken, there is no restriction to this. If
Fig. 1, a ROM cassette could be employed instead of a CD-ROM. These function as memory
media in which the operating program of an image generating device according to the
present invention is stored. Also, in the intersection determination processing, the
case where a structural object as already described is displayed incompletely and
in the case where this structural object is displayed using for example mesh polygons
or poly lines are to be taken as being covered by the mode "not displayed". Fig. 24
and Fig. 25 are respective examples of a human-like character (warrior) constituting
a model according to the present invention.
[0095] In glow shading by CPU block 10 (the same applies to other types of shading), processing
may be performed not only for all the polygons of a character but also for only part
of a character, in particular for a portion which it is desired to show three-dimensionally
by linear interpolation of colour (for example, polygons corresponding to exposed
skin). In this way, the load on CPU block 10 during execution of processing can be
reduced. In the case of the character of Fig. 24, glow shading may be performed only
in respect of the fist, face, and chest below the neck which are exposed from the
clothing; in the case of the character of Fig. 25, glow shading may be performed only
in respect of approximately the upper part of the body and the feet.
[0096] Also, although conventionally in the case of a quadrilateral polygon four vertices
were employed when Z sorting was applied to the polygons, it would be possible to
determine this using only the point of intersection (mid point) of the diagonals respectively
joining two vertices. As a result, processing speed can be improved by reducing the
frequency with which the main CPU accesses memory. It should be noted that, even though
Z sorting is applied using such a mid point, the same accuracy as in the case of Z
sorting using four vertices is still maintained, since this mid point represents the
average value of the four vertices. In the case of a triangular polygon, the centre
of gravity could be used. Next, another embodiment of processing operation of the
image generating device described above will be explained. Fig. 26 is a front view
showing details of the control pad 2b described above. This control pad is provided
with a direction key 26b as described above and buttons A, B, C, X, Y, Z, L and R.
Pressing this direction key or buttons corresponds to movement of a character (warrior)
of Fig. 24 or 25: for example, button A corresponds to "defensive action against attack
from another warrior", button B corresponds to "punch other warrior" and button C
corresponds to "kick aimed at other warrior".
[0097] The user i.e. the player controls a character as he wishes by operating this key
and/or buttons in various manners; however, a great deal of practice is required in
order to control a warrior moving very rapidly and with great versatility in an appropriate
manner.
[0098] Accordingly, in a mode of the processing described herein, as shown in Fig. 27, a
set of command moves constituted by pressing combinations of a plurality of buttons
are designated as "combination moves" and these are stored beforehand in working RAM
as a file. Then, by reading these by pressing one of the buttons described above,
the warrior can be made to execute the command moves in sequence. In Fig. 27, PPK
is equivalent to pressing button B, button B and button C in sequence and P+K is equivalent
to pressing button B and button C simultaneously. In addition, the number of frames
to be occupied by these moves can be set for each command move. Consequently, the
player can create combined moves in versatile fashion as he wishes since he can freely
set the number of frames of each command move in a combination move. A specific example
of such a combination move is "throwing the other warrior over one's head, and kicking
him when he gets up".
[0099] Continuing the description in more detail, "P, K, P" indicates that the punch button,
kick button and punch button are continuously pressed and, if we assume that an overhead
throw is performed if continuation of these is determined, when P is pressed, the
character goes into the punch motion. If K is pressed after the commencement of this
motion but for example before the motion goes into punch return, a kick is commenced
from the attitude of a delivered punch and with the timing of the punch return motion;
if P is input whilst the kick motion is being executed, this is deemed as a continuous
move and continuance is effected with the overhead throw motion (command move). If
the timing at this point is made to coincide with the timing at which the other character
is about to fall over, a very effective overhead throw can be created in which moves
are easily applied to the same overhead throw.
[0100] A player can create a plurality of such combination files and allocate a single button
to each file. Of course, if the player presses a button to which no such combination
file has been allocated, the single move that was originally allocated to this button
is executed. What range of buttons are to be used to register combination moves may
be suitably determined in accordance with requirements for combination moves and requirements
for single movements. A plurality of buttons could be allocated to individual files.
[0101] Next, the operation of this processing will be described with reference to the flow
chart shown in Fig. 28. First of all, in step S280, a determination is made as to
whether a button as described above has been pressed. If a button has been pressed,
if a combination move is registered in respect of the button that has been pressed
(step S282: affirmative), in step 284, the commands in the combination moves registered
in working RAM (equivalent to pressing plural or single buttons) are sequentially
read. Next, in step S286, a determination is made as to whether or not the command
in the file has been executed as far as its end; if this is affirmed, this flow chart
is repeatedly executed until it terminates. In contrast, in step S280, if no button
has been pressed, return is effected; and, in step S282, if no combination-move file
is registered for a button that is pressed, the single move allocated to this button
is executed.
[0102] In the presently described mode, a combination of action commands to a character
(model) (e.g. combination of operating switch presses: pressing a single switch, pressing
a plurality of switches, pressing the switches in sequence, or pressing the switches
simultaneously) is stored in memory; the means for image processing reads this by
a simple switch operation such as for example pressing a single button, and the movement
(motion) of the model is continuously controlled in accordance with the group of commands
that are thus read. Consequently, as described above, the user can represent more
versatile movement (motion) of the model as he wishes, without complicated key operation.
[0103] Fig. 29 shows the initial screen for mode selection that is displayed on the monitor
when combination processing as described is to be performed: in order to select a
combination move, an icon at the top right is selected. Fig. 30 is a screen showing
the case where a button (key) has been assigned to a move; Fig. 31 is a screen for
compilation of the combination-move file; and Fig. 32 is a screen showing one condition
wherein warriors are in mutual combat condition. Fig. 33 is a screen that is deployed
later on the screen of this one condition and shows a condition in which a warrior
( "Akira" ) has been knocked down by the warrior ("Rau"). It should be noted that,
as can be seen from Fig. 33, when one warrior has knocked down another warrior (when
this has been determined by the CPU block ) , the character 330 on the screen is made
to display this. In Fig. 33, this is displayed by changing a "plant-like bud character"
to a "plant-like open-flower character".
[0104] It should be noted that the present invention is not restricted to the embodiment
described above but could be further modified in various ways by persons skilled in
the art within the scope of the claims.
[0105] As the memory (recording) medium for storing the operating program of the games machine,
apart from cartridge ROM or CD-ROM as described above, communication media such as
the Internet or personal computer networks could be used; an electronic mail server
is also included.
1. Bildverarbeitungsvorrichtung für Spiele vom Typ Kampfspiele, wobei die Vorrichtung
so ausgelegt ist, dass sie: i) in einem virtuellen Raum ein erstes Modell (30), das
von einem Spieler gesteuert wird, und ein zweites gesteuertes Modell (32) aufbaut,
wobei das erste Modell und das zweite Modell einander bekämpfen; und ii) diese Modelle
derart steuert, dass sie sich in vorgeschriebenen Richtungen in dem virtuellen Raum
bewegen, und Anzeigemittel (5) veranlasst, Bilder dieses virtuellen Raums von einem
virtuellen Ansichtspunkt aus anzuzeigen, wobei die Vorrichtung Mittel (10) für eine
Bildverarbeitung (S200) umfasst, wodurch die Ausführung einer von einem Spieler, der
das erste Modell steuert, vorgeschriebenen Bewegungsoperation, während das Spiel läuft,
das Aufbauen einer virtuellen Anziehungskraft zur Folge hat, die zwischen dem ersten
Modell und dem zweiten Modell wirkt und zur Folge hat, dass sich das erste Modell
automatisch um das zweite Modell bewegt, das ein Zentrum der virtuellen Anziehungskraft
ist.
2. Bildverarbeitungsvorrichtung nach Anspruch 1, wobei die Bildverarbeztungsmittel (10)
ferner so betrieben werden können (S202), dass ein Betrag einer Reibungskraft, die
auf die Modelle einwirkt, in Abhängigkeit davon, ob sich die Modelle bewegen oder
ob sie unbeweglich sind, verschieden ist.
3. Bildverarbeitungsvorrichtung nach Anspruch 1 oder Anspruch 2, wobei die Bildverarbeitungsmittel
(10) ferner so betrieben werden können (S204), dass ein Projektionsbild der Modelle
gezeigt wird, das auf die Oberflächengestalt eines Schauplatzes, an dem sich die Modelle
befinden, abgestimmt ist.
4. Bildverarbeitungsvorrichtung nach einem der vorhergehenden Ansprüche, wobei die Bildverarbeitungsmittel
(10) ferner so betrieben werden können (S206), dass ermittelt wird, ob das Sichtfeld,
das durch den virtuellen Ansichtspunkt in Bezug auf das Modell, das Gegenstand der
Anzeige ist, und ein anderes Modell, das nicht als Gegenstand der Anzeige festgelegt
ist, überlappen, und wenn das Ergebnis dieser Ermittlung positiv ist, das andere Modell
nicht angezeigt wird.
5. Bildverarbeitungsvorrichtung nach einem der vorhergehenden Ansprüche, wobei die Bildverarbeitungsmittel
(10) ferner so betrieben werden können (S208), dass in Bezug auf den Endpunkt einer
im Voraus festgelegten Bewegungsbahn des Modells ein Zielpunkt angeordnet wird, der
von diesem Endpunkt verschieden ist, und die Bewegungsbahn derart interpoliert wird,
dass der Endpunkt mit diesem Zielpunkt zusammenfällt.
6. Bildverarbeitungsvorrichtung nach einem der vorhergehenden Ansprüche, wobei die Bildverarbeitungsmittel
(10) ferner so betrieben werden können (S210), dass ein Unterschied der Höhe, auf
welcher das Modell in dem virtuellen Raum angeordnet ist, festgestellt wird, und die
Aktion, die für dieses Modell vorgesehen ist, in Übereinstimmung mit diesem Höhenunterschied
interpoliert wird.
7. Spielevorrichtung, die eine Bildverarbeitungsvorrichtung nach Anspruch 1 enthält.
8. Spielevorrichtung nach Anspruch 7, ferner umfassend: Eingabemittel (2b) für die Steuerung
der Bewegung der Modelle, wobei die Eingabemittel Richtungstaste(n) (26b) umfassen,
um die Aktionsrichtung eines betreffenden Modells vertikal oder horizontal zu spezifizieren,
wobei die Bildverarbeitungsmittel (10) so betrieben werden können, dass sie eine Bildverarbeitung
in Reaktion auf eine Betätigung der Richtungstaste(n) ausführen, derart, dass automatisch
eine Kreisbewegung des Modells bewirkt wird.
9. Aufzeichnungsmedium (1), auf dem ein Bildverarbeitungsprogramm aufgezeichnet ist,
das so ausgelegt ist, dass es den Betrieb einer Spielevorrichtung beim Spielen eines
Spiels vom Kampfspieltyp steuert, so dass: i) in einem virtuellen Raum ein erstes
Modell (30), das von einem Spieler gesteuert wird, und ein zweites gesteuertes Modell
(32) aufgebaut werden, wobei das erste Modell und das zweite Modell einander bekämpfen;
und ii) diese Modelle derart gesteuert werden, dass sie sich in vorgeschriebenen Richtungen
in dem virtuellen Raum bewegen, und Anzeigemittel (5) veranlasst werden, Bilder dieses
virtuellen Raums von einem virtuellen Ansichtspunkt aus zu zeigen;
und eine Bildverarbeitung (S200) ausführt, wodurch die Ausführung einer von einem
Spieler, der das erste Modell steuert, vorgeschriebenen Bewegungsoperation, während
das Spiel läuft, das Aufbauen einer virtuellen Anziehungskraft zur Folge hat, die
zwischen dem ersten Modell und dem zweiten Modell wirkt und zur Folge hat, dass sich
das erste Modell automatisch um das zweite Modell bewegt, das ein Zentrum der virtuellen
Anziehungskraft ist.