JPH03211686A - Computer control display method and apparatus - Google Patents

Abstract

PURPOSE: To facilitate the three-dimensional movement of an object on a display screen by displaying a shadow area relating to a cursor. CONSTITUTION: In an interactive computer controlled display device, the cursor 2 provided with a, position corresponding to the three-dimensional movement of a cursor controller and provided with at least one edge is displayed on a data display screen 1. Then, the shadow 3 provided with the edge corresponding to the edge of the cursor 2 projected on a two-dimensional shadow plane 4 along a light vector and provided with the position corresponding to the three- dimensional movement of the cursor controller is displayed on the display screen 1. Thus, a user is helped to discriminate the movement and position of the object in a space.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a computer system having a three-dimensional cursor displayed on a computer-controlled display device. More particularly, the present invention provides an interactive computer system having a cursor capable of representing three-dimensional motion as the cursor moves across a display or screen.
Regarding the system.

BACKGROUND OF THE INVENTION Computer-controlled display devices are useful for graphically displaying three-dimensional (3D) objects in three-dimensional spatial relationships. This is particularly true when the displayed object is moved around in 3D space using a cursor control device. but,
Since a screen is only a two-dimensional plane, it is difficult to model 3D space onto a display screen (eg, a CRT computer ψ monitor).

In the conventional technology, due to the limitation of this two-dimensional screen, when the user attempts to move the cursor in 3D space,
The display image was confusing. Therefore, it was not easy to determine the depth and height of an object without some reference point. It is difficult to judge.The conventional 3
Dimensional modeling techniques do not use shadowing of an object with respect to a cursor, with an associated shadow region, as a means to help a user discern the object's motion and position in space. Due to these problems, computer display devices have not been rapidly produced as a means for displaying a three-dimensional space and a cursor display therein.

SUMMARY OF THE INVENTION The present invention provides an apparatus and method for facilitating three-dimensional movement of objects in a display screen by displaying a shadow region associated with a cursor. The shadow area helps the user orient the relative position and movement of objects in 3D space. In this embodiment, the shadow area is the display e.
The shadow area is shown as a drop shadow because it is displayed on a shadow plane located below the screen.

The present invention is directed to a system component device, that is, a processor,
Random-access memory, read-only memory, data storage device for storing data, data display device including a display screen, European numeral input device, cursor control for interactively positioning a cursor on a display screen The present invention also provides an apparatus and method for displaying a shadow area associated with a three-dimensional cursor, thereby providing an apparatus and method for displaying a shadow area associated with a three-dimensional cursor. The shape (including size) and orientation of the shadow can be considered depending on the 3D movement of the device.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiments The present invention provides an apparatus and method for generating and displaying a shadow area associated with a three-dimensional cursor displayed on a display device. This glossy area represents the shadow of the 3D cursor and moves with the cursor as it moves across the display device.

An embodiment of the present invention is an Apple-Matsukintrasch T''
-Embodied in computer systems. However, it will be obvious to the watchman that other systems may be used. Generally, such systems
A bus 10 for communicating information as shown in FIG.
0 and a processor 1 connected to the bus and processing information.
01 and the bus 100, and the processor 10
a random access memory 102 for storing information and instructions for the processor 1;
Read-only memory 10 for storing static information and instructions for 01
3, a data storage device 104, such as a magnetic disk and disk drive, connected to the bus 100 and for storing information and instructions; and a display device 105, connected to the bus 100, for displaying information to a computer user. , a European numeral domain device 1 connected to said bus 100 and including European numerals and function keys for communicating information and command selections to said processor 101.
06, and a cursor control device 10 connected to the bus and communicating information and command selections to the processor 101.
7, connected to the bus 100, and connected to the processor 101.
and a signal generator 108 for communicating command selections.

The display device may be a liquid crystal device, a cathode ray tube, or any other suitable display device. A display device must be able to display a small number of discrete points and vectors on the display screen. More advanced display devices must be able to display areas on the display screen in various colors or shades of gray. can do.

The cursor control device 107 allows the computer user to
It is an interactive device that can dynamically signal the movement of objects visible in three dimensions on a display screen. 3-axis mechanical device (e.g. trackball) or 3-axis mechanical device (e.g. trackball)
Multi-dimensional magnetic field sensing and positioning device
D-cursor control devices are well known in the art. Other types of cursor control devices are only capable of signaling movement in two dimensions. Other signaling means can be used to provide a three-dimensional signal when used as a
8.

The European numeric keyboard 106 can also be used alone to generate three-dimensional signals. Particular keys on the keyboard can be designated to signal movement in each of the three dimensions. These cursor control devices are
Movement of the cursor in the Y, Z directions provides data to the processor.

In this example, the x, y, and z directions are defined as follows. The screen origin is defined as the lower left corner of the display screen, and X is
Y is the axis that runs from the left side of the display screen to the right side of the screen and parallel to the plane of the screen.
The axis is perpendicular to the Extending perpendicular to the display screen straight outward toward the viewing user.

The shadow characteristics and hyphrocess of the three-dimensional cursor of the present invention will be explained below. Since the general operation of cursor control or display devices is well known in the art, only that portion necessary for a thorough understanding of the present invention will be described.

OPERATION OF THE INVENTION Cursor shadow 3 shown in FIG. 1 is a displayed image associated with a 3D cursor that moves with cursor control device 1107. The two-dimensional shape of the shadow corresponds to the three-dimensional shape of the cursor 2. In the present invention, cursor 2 is displayed as a 3D object. A 3D object is a solid defined with vertices located in three-dimensional space connected by straight edges. These edges are connected to form polygons that define the faces of the solid. For each polygon face, the edges that make up the face are in the same plane,
Therefore, each face has an associated normal vector that is perpendicular to the face and each edge therein. Each edge and each side is
Has an associated color shade of gray, or display illumination. The surface of each side may be opaque or transparent.

As shown in Figure 2, an object composed of opaque surfaces 2 casts a homogeneous shadow 3 for each opaque surface exposed to a light source 7 (shown in Figure 5). transparent side 3
The object created in step 2 forms a shadow 34 of only its edges.

This type of object can be created using wires as shown in Figure 3.
Represented as a frame solid 32.

A 3D cursor object can also be displayed as a 3D non-solid object 31. That is, the object has no faces or internal areas. Objects of this type are displayed as vectors. Similar to solid calligraphy objects, vectors move in response to movement of cursor control device 107. As shown in FIG. 3, crosshair 31 illustrates an example of a non-solid cursor object.

Non-solid cursor objects are shown in the present invention as some 3D points connected by vectors. There are no associated polygons or faces here. In the case of crosshair cursor 31, an object can be represented by four points. Two for each vector form a crosshair. When points are shown as vertices and vectors are shown as edges, non-solid objects can be represented in the same way as solid objects, except that there is no need to handle faces. As with solid objects, each edge (vector) has an associated color, shade of gray, or illumination. Non-solid objects form shadows 33 only about their edges.

All 3D objects of the present invention are represented in a data structure as a collection of vertices, faces, and edges. The data structure is stored in computer memory 102, magnetic storage means 104
, or other suitable data storage device. For each vertex of the object, the x, y, z position of the vertex is stored in a data structure. For each face of the object, the data held in the object data structure includes the number of vertices in the face, a pointer to each associated vertex, the color of the face, the magnitude and direction of the vector perpendicular to the face, It is not limited to this. Also, for each edge, the stored data includes pointers to the start and end vertices of the edge, pointers to the faces of which this edge is part, and the color or illumination of the edge.
It is not limited to this. For non-solid objects, the same object data structure can be used, but the objects do not have faces, only vertices and edges. Since the cursor is an object, object-data associated with the cursor (cursor-data) is also stored in the object φ data structure.

Each object and each object's shadow are displayed on the display screen 1 with respect to the eye body 6.
will be displayed on. The eye position 6 shown in FIGS. 4 and 5 is a known point in space in front of the display screen. Ai Bojishi 1
Point 6 is the point at which the user views the displayed image.

In an embodiment of the invention, this position is i (x+ y+ z,
) is defined as a point in 3D space. The eye preference position e6 does not necessarily have to be fixed. Furthermore, the eye position 1 pin 6 may be in a different position from that shown in FIGS. 4 and 5. The VitII shown here can also be used in embodiments using variable eyeballs.

Each image is transferred from a three-dimensional space to a two-dimensional screen
displayed to the user as a projection onto 5.

Typically, the screen plane 5 of a CRT display device is perpendicular to the Z axis as shown in FIGS. 4 and 5. The projection is used to determine the point in the screen plane 5 that intersects the line joining the vertices of each object to the eye position 1 6. For example, as shown in FIG. 5, point p is the intersection of screen plane 5 and line Ai. Line Ah5
3 connects the object's vertices to the coordinate space origin (h). Vector N8 is a normal vector perpendicular to screen plane 5. The normal N is calculated using a cross product of the screen plane with two separate unit vectors, a well-known technique. Intersection point p of screen plane
The position of is obtained by first calculating the dot product of the vector Ah53 and the normal vector N of the screen.

Next, the vector A15 with the normal vector N of the screen
The heavenly product of 1 is calculated. A +
Multiply the X and Y components of the vector and add it to the coordinate components of the object's vertices. The result is a point p in the screen plane 5 that intersects the line from the object's vertex to the eye position 6. The projection of each object's vertex is calculated as shown in the following equation for the cursor's vertex A.

p (x) = (dot product (N, Ah) / dot product (N.

Ai) ・Ai (x)+A (x)p (y) =
(Dot product (N, Ah)/Dot product (N.

Ai)/At (y) +A (y) p (z) = Screen plane (z) The positions of the vertices of each other object when projected onto the screen plane 5 are similarly calculated and stored in the object data structure. be done. Although there are other means of projecting vertices onto a plane, the above-mentioned means are the only satisfactory methods used in the embodiment of the present invention.

The cursor 2 changes its position and orientation on the display screen l in response to the three-dimensional movement of the cursor control device 107. Cursor control device 107 connected to processor 101 via bus 100 as shown in FIG.
are each of the three axes X.

Processor 10 showing movement of cursor 2 along Y, z
1. As mentioned above, cursor 2 3
D-motion can also be signaled using other methods.

Two-dimensional cursor control devices used with other signal means may also be used to generate the 3D signal. Similarly, only the European numeric keyboard 106 may be used as the 3D cursor control device. As will be described later, the processor logic unit determines the vertices, faces, and
Give the edges three-dimensional motion, compute a new projection onto the screen plane 5 for each cursor vertex, generate a shadow 3 associated with cursor 2, and compute a new projection onto the screen plane 5 for each shadow vertex. .

Shadow 3 itself is a polygon group (shadow area),
Or it is a two-dimensional shape that can be displayed as a group of edges (shadow edges). Shadow polygon 3 is formed by the opaque surface of the object. Edge shadows (33, 34) are formed by transparent surface objects 32 or non-solid objects 31. Shadow 3 is related to cursor fist object 2 as determined by the position of the object vertex of three-dimensional cursor 2 stored in the object data structure. The vertices of the cursor 2 are translated to a two-dimensional shadow plane 4, resulting in shadow vertices. The shadow plane 4 in this embodiment is perpendicular to the Y axis and located below the display screen 1 as shown in FIG. The shadow plane 4 is limited to simulating an infinitely large plane of parallel light sources. The light source is perpendicular to the Y-axis and its light beam travels downward parallel to the Y-axis. The shadow vertices define the relationship between the position of shadow 3 and the position of cursor 2. Shadow calculation in this embodiment is performed using the following equation regarding cursor vertex A.

a (x) ”A (x) a (y) = Nyadou plane (y) a (z) = A (z) Nyadou vertex (for example, a (x, y+ z)
) is the cursor object vertex (for example, A(
X+y,z)), so when the cursor moves, the shadow vertex also moves. The position of each shadow vertex is computed with respect to cursor movement and stored in an object data structure. For solid objects, pointers to the shadow vertices associated with each face are also maintained in the object data structure.

Similar to objects, shadows can be seen by the user as images projected onto the screen plane 5 as shown in FIGS. 4 and 5. This calculation is the same as the calculation performed when projecting the object vertices onto the screen plane 5 as described above. Projection is used to determine the point in the screen plane 5 that intersects the line joining each shadow vertex to the eye position I6. For example, as shown in FIG. 5, point q is the intersection of line ai and screen plane 5. The line ah connects the object's vertices to the coordinate space origin (
h). Vector N8 is a normal vector perpendicular to screen plane 5. Intersection q of screen plane
The position of is first obtained by calculating the dot product of the vector ah with the screen normal vector N. Next, the dot product of the vector ai and the normal vector N of the screen is calculated. X of the ai vector at the dot product of ah divided by the dot product of ai.

The Y component is multiplied and added to the coordinate component of the shadow vertex. The result is a point q in the screen plane 5 that intersects the line from the shadow vertex (a) to the eye-posiscene 6. The projection of each shadow vertex is the shadow vertex (
It is calculated as shown in the following formula regarding a).

q (x) = (dot product (N, ah) / dot product (N.

ai)・a i (x) +a (x)q (y)
= (Dot product (N, ah)/Dot product (N.

ai)・a i (y) +a (y)q (z)
=screen plane (z) The position of each other shadow vertex projected onto the screen plane 5 is similarly calculated and stored in the object data structure.

Movement of the cursor results in a corresponding movement of the screen plane projection point of the shadow vertex. For non-solid tube objects, shadow generation is simply a matter of projecting the shadow vertices onto the screen plane and creating vectors between the projection points of the screen plane.

For solid objects, including objects with opaque or transparent surfaces, shadow generation is not straightforward. That is, not all faces of a solid object produce shadows.

Furthermore, the edges of each surface do not necessarily produce clear shadows. The present invention provides processing logic to determine which faces of a solid object form shadows and which do not. Since unshaded surfaces do not cast shadows, there is no need to draw a shadow image on the display screen for these surfaces. Shadows are drawn on shadowed surfaces.

The normal vector associated with each face is used to determine whether the face is shaded. The dot product of the vector pointing straight at the light source 7 and the normal vector of the surface is calculated. If the dot product is positive, the surface forms a shadow. If the dot product is zero, the surface is parallel to the light source 7. If the dot product is negative, the face is hidden from the light source by other faces (only true for closed solids) and no shadow is formed.

The normal vector of a surface can be calculated by performing a cross product of the two edges of the surface, as shown in the example for surface CAD in FIG.

Predetermined vectors: vl = vector (AC) v2 = vector (AD) Normal vector two cross product (v 1+
v 2 ) For each face of the solid, the normal vector is calculated and tested against the dot product calculated for the light vector as described above.

If the surface is in shadow (because the dot product is positive), a shadow image is drawn on the screen plane, as described below.

Since the surface can be either opaque or transparent, two processing methods are possible to optimize the drawing of the shadow image. In the case of an opaque shadowing surface 2, an opaque shadow area 3 results. This shadow region is displayed by drawing an opaque polygon in the screen plane using the projected shadow vertices associated with this surface.

The positions of the projected shadow vertices are calculated and stored in the object data structure as described above.

These vertices become the corners of the shadow area in the screen plane. There are currently many methods in the field of computer graphics for displaying fill areas on a display screen in this manner.

In the case of a transparent shadowing surface 2, a transparent shadow area 34 is formed. This area is linearly acidified onto the display screen by drawing the edges of the surface. Using the projected shadow vertices associated with this face, edges are drawn in the screen plane as vectors using the projected shadow vertices as end fist points. Since each edge is a component of more than one face, it is possible that each edge is drawn more than once. The present invention tests for this possibility and ensures that the same edge is not drawn more than once. When each edge is drawn, the pool flag (located in the object data structure for each edge) is set to a true value, preventing the same edge from being drawn subsequently.

The cursor 2 of the present invention is activated using a funxilon key or signal generator 108 associated with a three-dimensional cursor. Shadow 3 is automatically displayed with respect to the 3D cursor 2 display. Many other means of function activation may be used, such as entry of special codes or command sequences from the European numeric keyboard 106 or icon selection.

An icon may be a small graphic symbol displayed to the user to identify what function it is performing when selected. The present invention can also be activated by a software interface with the combiator's operating system software or other application planning software. Using this method, the activation of the 3D cursor and associated shadow becomes independent of direct user action.

Once activated, the 3D cursor 2 is shown to the user on the display screen 1 as shown in FIG. The cursor 2 is displayed on the shadow plane 4 along with the display of its associated shadow 3. shadow 3
The shape and orientation of corresponds to the shape and orientation of the 3D cursor 2 in the manner described in a. Cursor control device 1
When 07 moves, 3D cursor 2 and shadow 3 move correspondingly. The 3D cursor 2 allows movement beyond the visible part of the display screen 1. If cursor 2 is moved over the top border of display screen 1, cursor 2 disappears, but
Shadow 3 is still displayed. Even if the cursor 2 is hidden behind other objects on the display screen 1, the shadow 3 is still visible.

If cursor 2 moves below shadow plane 4, cursor 2 is displayed, but shadow 3 is no longer displayed.

The shadow 3 itself is displayed to facilitate movement of the cursor 2 in three-dimensional space.

When the user looks at the cursor with respect to shadow 3, he can judge height and distance more accurately. In this example, shadow 3 appears to be formed directly below cursor 2 (which is derived directly from the X and Z coordinates of the cursor vertex to the X and Z coordinates of the shadow vertex). In another embodiment, the shadow vertices are not formed directly from the cursor vertices because the shadow is formed at an angle 111 (shown in Figure 11) to the cursor rather than directly below it. Angles are given in either or both of the X and Y axes. For example, the light source 7
When illuminating with a parallel ray 110 (light vector) as shown in Figure 1, the shadow vertex passes through the cursor vertex and the light source ray 1 passes through the cursor vertex until the ray intersects the shadow plane 4.
Calculated by extending one of 10.

Processing Logic of the Invention The present invention includes computer program logic for the operation of a 3D cursor and its corresponding shadow. This logical method embodied by processor 101 is described with respect to FIGS. 6-9. In addition to the computer resources discussed above, the present invention utilizes the availability of an operating system and system functions that can display vectors on display device 105. A system funxigin that interfaces with the cursor control bag mi 07 is also desirable, but not necessary. These resources are standard processing components well known in computer technology.

The system components of the present invention are initially
(Typically, read-only memory 10
3 and embodied by processor 101), the operating system logic unit (located at 3 and embodied by processor 101) performs control.
, and read/write memory 102, display device W
105, initializing other system components such as cursor control device 1107; At the end of its initialization cycle, or in response to a user command, the operating system initializes the functionality of the 3D cursor. When initialized by activation of a funxisine key by the user, the 3D cursor's program logic begins execution when the appropriate funxisine Φ key is activated.

As mentioned above, other devices for activating the 3D cursor may be used.

Once the 3D cursor program logic is activated, the process flow begins at ``Start 3D Cursor and Shadow System'' 601 as shown in FIG. First, the display device hardware is initialized 602. The next operation performed by the program logic is to display all defined objects in the object data structure. This data structure holds data definitions (vertices, faces, and edges) of all objects that can currently be displayed in three-dimensional space. One of these objects is a cursor.

The program logic unit is block 603 in FIG.
Start the loop with . This loop initializes a new image memory, updates the object's position in the object-data structure, and displays each object's shadow as the cursor 11 controller moves. First, the new image memory is erased at 603. The new image memory is a temporary buffer in which the new display screen image is constructed. Each object displayed on the display screen is
When the object being processed is completed for that object, a new ~1 image is added to the memory. When the new image is fully established, the new image memory is copied to the display screen 0 memory and the display screen displays the new image. After the new image memory is erased 603, a shadow plane is drawn 6100 in the new image memory.The shadow plane 4 is shown in FIG. Next, the pointer is initialized and the top of the object data structure is indicated 81
1. Each object has no object to be processed (
605, retrieved from the object data structure 604. If all objects have been added to the new image memory 607, program control returns to D in FIG.
will be forwarded to. , D, the new image memory is copied to the display screen memory 613; then the image in the display screen memory is copied to the display screen memory 613;
12. The loop for displaying objects begins again at block 603. If another object is found in the object red data structure 606, the object is retrieved 604 and processor control is transferred to A in FIG.

The start at A in Figure 7, i.e. the shadow (
A Boolean flag called the Show Shadow flag is initially set to false.The Boolean flag indicates whether the current object's shadow should be displayed. Next, a new transformation matrix is generated 7010. Generation of transformation matrices is well known in the art. The transformation matrix defines the movement of the cursor control device along each of the three axes x, y, z. This motion is then provided to each vertex of the object-data structure in processing block 702. When the new 3D position of each vertex is calculated, the Y component of the position is checked against the Y position of the shadow plane. If any vertex of the object is placed above the shadow plane 703, the object's shadow is signaled to be displayed by setting the pool shadow flag to true.
04゜Otherwise, the shadow will not be displayed (the shadow activation flag remains false7)
11).

For each vertex, the 3D position of the vertex is translated 705 to the shadow plane and projected 706 to the screen plane for display.
c, Dd This is carried out by setting the Y coordinate value of the vertex position to the Y coordinate value of the shadow plane, as shown in (35). If necessary, the 11th r! ! 111. which is angled considering the light source arranged as shown in J. The projection 706 onto the screen plane is performed by calculating the position of the intersection of the screen plane 5 with the vector joining the vertices of the object and the eye-posiscene 6, as described above. The projection of each vertex onto the screen plane is
The object itself (the vertex of each object) 706,
It is calculated for the object's shadow 707 (each shadow vertex).

In Figure 5, the screen projection point of the cursor vertex is N
Denoted as m, n+ OT p. The screen projection point regarding the shadow vertex of the cursor is Q+
1'+81j. After projecting the object and shadow vertices onto the screen plane, the program execution loop returns to processing 708 the next object's vertices until all vertices for the object have been processed. If the eye position 1 is below the shadow plane, the shadow is not visible from the eye position 1 below the shadow plane, so the shadow shadow flag is set to 717°. , 716 is above the shadow plane, the shadow flag remains previously set. The process is shown in B in Figure 8.
continues for object faces and edges in .

The faces of each object are processed as shown in FIG. If the object is non-solid 805, the surface is (
, the process proceeds to step C in FIG. Since each face of the object does not have to form a shadow, the processing loop from B to C is performed for each object face defined in the object group data structure. This loop is used to determine whether the surface is visible from the eye positilon and whether the surface forms a shadow region in the shadow plane. Initially, each facet of the current object is retrieved from the object group data structure 80
A 1° normal vector is calculated for the surface.The 802° normal vector is calculated by performing a cross product of the two edges of the surface as described above. The cross product is
yields a normal vector perpendicular to the surface. Initially, the normal vector of the surface is 810°, which is used to determine whether the surface is visible from the eye surface. This normal vector of the surface points straight away from the eye surface 6. It is used to calculate the dot product of a negative vector and a surface normal vector. If this dot product is greater than zero, 8111 planes can be seen. In this case, if the 813° surface is not visible in the new image, 812
, no faces are drawn in the new image.

Next, surface shadows are processed. If the one shadow flag is true 815, shadow processing for the surface continues as shown in FIG. 8E.

If the image shadow flag is incorrect 816, control passes to the next plane at FIG. 8B. Regarding the shadow processing at E in FIG. 8, the light source 11
The surface normal vector is used to calculate 813 the dot product of a negative vector pointing straight away from zero and the surface normal vector. If this dot product is greater than zero 807, the surface is shaded. In this case, the shadow area is
It is drawn using the previously calculated shadow vertices projected onto the screen for this face. The color or illumination of the shadow area is predefined in the object data structure. As previously calculated, shadow areas of surfaces with zero or negative dot product 806 are not drawn. If each side is to be processed 809, the edge processing process begins at C in FIG.

Each object edge requires a separate processing step as shown in FIG. As mentioned above, there are at least 2N classes, ie, solid and non-solid objects. Furthermore, there are at least two types of solid φ objects: objects with opaque surfaces and objects with transparent surfaces. For solid Φ objects with opaque surfaces, shadows are drawn by colored or shaded shadow areas, so edge shadows are not drawn (which is fine; in this case, 906, the program runs in Figure 6D) Back. For solid objects with non-solid or transparent faces, the object O shadow is not visible, so edge shadows must be drawn 907
Therefore, if each edge of an object defined in the object data structure is retrieved from the object data structure as shown in FIG. If is true 909, then the edge's shadow is drawn using the projected shadow vertices calculated 904° before the edge's shadow is drawn on the display image. Once each edge has been processed 9101, program execution returns to FIG. 6D where the processing of the object begins again with respect to the new cursor position.

As mentioned above, although the present invention has been described based on examples, it is clear that the present invention is not limited to these examples.

[Brief explanation of drawings]

jFIIiliff shows a three-dimensional cursor with shadow displayed on the display screen after activation, FIG. 2 shows a three-dimensional cursor and shadow with defined vertices and axes, and FIG. 3 shows a wire O-frame object. 4 shows a shadow in the x-2 plane, FIG. 5 shows a shadow and a cursor in Y-2, and FIGS. 6 to 9 illustrate the present invention. A flowchart of a typical computer program realized is shown,
FIG. 10 shows the architecture of the computer system, and FIG. 11 shows the shadow and cursor in the Y-Z plane with a light source positioned at an angle to the Y-axis. 2. Meeting...Cursor, 3 fists...Cursor shadow,
4...Shadow plane, 5...Screen plane,
6II @ @ @ Eye Posisilon, 100...Fist bus, 101...@-Processor, 102...Random access memory, 103...Read-only memo 1c 104...Data storage Device, 105.-
・・Display device, 106IIIll・European numeral input device, 107・@Q・Cursor control device, 108・・
Φ・Signal generator.

Claims (3)

[Claims] (1) An interactive computer-controlled display device having a processor, a data display screen connected to the processor, and a cursor control device connected to the processor for interactively positioning a cursor on the display screen, The method of controlling the display of a shadow associated with the cursor includes generating on the data display screen a cursor having a position responsive to three-dimensional movement of the cursor control device and having at least one edge; displaying the cursor, the cursor having an edge corresponding to an edge of the cursor projected onto a two-dimensional shadow plane along a light vector and having a position responsive to three-dimensional movement of the cursor control device; generating and displaying a shadow associated with a cursor on the display screen; (2) an interactive device having a processor, a data display screen connected to the processor, and a cursor control device connected to the processor for interactively positioning a cursor having at least one edge on the display screen; a computer-controlled display device connected to the processor for generating and displaying a cursor on the data display screen having a position responsive to three-dimensional movement of the cursor control device; a shadow associated with said cursor having an edge corresponding to an edge of said cursor projected onto a two-dimensional shadow plane along a light vector and having a position responsive to three-dimensional movement of said cursor control device; , and a device for generating and displaying on said display screen. (3) A method for controlling the display of a shadow associated with an object in an interactive computer-controlled display device having a processor and a data display screen connected to the processor, comprising: generating and displaying a shadow associated with said object on a data display screen, having an edge corresponding to an edge of said object projected onto a two-dimensional shadow plane along a light vector; A method for controlling the display of a shadow associated with an object, comprising the steps of: generating and displaying on said display screen.