JPH07105409A - Collision detector device for three-dimensional moving object - Google Patents

Abstract

PURPOSE:To provide a three-dimensional mobile object collision detector capable of quickly detecting the collision of a three-dimensional moving object in respect to the detection of collision in real time walk through or the like on a three- dimensional picture. CONSTITUTION:A plan view storing part 1 stores two-dimensional data expressing a graphic obtained by projecting structure arranged from a moving plane up to a reference plane in three-dimensional data clipped on the moving plane to the reference plane in parallel as a plane view 5 and an instruction part 2 successively inputs two-dimensional coordinate values indicating points obtained by projecting respective current positions of points representing a moving object to a judging part 3 as current position coordinates. A segment generating part 6 in the judging part 3 generates a segment connecting both points between the current position coordinates and coordinates to be stored in a preceding position storing part 4, an intersection detecting part 7 identifies an intersection between the structure projected in parallel on the plan view 5 and the segment generated by the generating part 6 and returns the existence of the intersection to the instructing part 2 and the storing part 4 updates its stored contents to the current position coordinates processed by the judging part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for sequentially generating three-dimensional perspective view images showing a landscape inside a building from a three-dimensional data as a viewpoint moves in a so-called real-time walkthrough system. Therefore, the present invention relates to a collision detection device for a three-dimensional moving body that detects that a moving body such as a viewpoint collides with an obstacle structure.

[0002]

2. Description of the Related Art As is well known as the so-called real-time walkthrough in so-called computer graphics (CG) technology, so-called C
It displays a three-dimensional image of a building designed by AD etc. so that it looks like walking through the inside of the building, and represents an observer. A real-time walkthrough is a technique for generating a three-dimensional image in the field of view when viewing a required direction from the viewpoint according to the movement of the viewpoint defined as a point, and displaying the animation. It is an effective technology in the field.

Here, extremely high-speed real-time image processing is required to display a high quality image that looks natural, but three-dimensional image processing generally requires a huge amount of calculation.
It takes a few seconds to a few minutes to create one frame image with a general computer.

Therefore, dedicated hardware for three-dimensional image generation has been developed, and by using it, it has become possible to generate several frames to several tens of frames per second.

However, there is a problem peculiar to the real-time walkthrough. In particular, for example, the operator uses an input means such as a mouse to instruct a route so that the operator can freely walk in the building, and the interior scenery is accompanied by the instruction. In the case of displaying, it is necessary to facilitate the input, and one of the functions provided for that purpose is the collision detection between the observer and the structure.

Here, the collision detection is to detect the movement of a point of a moving body such as the above-mentioned viewpoint such that it passes through a place where a building or the like cannot originally enter (eg, penetrates through a wall). When such a thing is detected, it is necessary to avoid displaying an image that is impossible in nature and take measures such as issuing a warning and revising the instruction.

In general collision detection, obstacles such as walls and installations are specified in the space represented by the target three-dimensional data, and the moving path of the moving body is such that all obstacles in the space are obstructed. Since a process of identifying that the object does not intersect with each other is performed for each movement, the collision detection requires a relatively long processing time.

It is an object of the present invention to provide a collision detecting device for a three-dimensional moving body capable of executing collision detection at high speed under conditions such as real-time walkthrough in a building.

[0009]

FIG. 1 is a block diagram showing the configuration of the present invention. The figure shows the structure of a collision detection device for a three-dimensional moving body, and for a structure in a three-dimensional space represented by three-dimensional data, a moving plane parallel to the reference plane set for the structure. A device for detecting a collision between a moving body represented by a point moving inside and a structure arranged on the reference plane, which is a plan view storage unit 1, an instruction unit 2, and a determination unit 3. And a front position storage unit 4.

In the first invention, the plan view storage unit 1 is
With respect to the three-dimensional data clipped on the moving plane, two-dimensional data representing a figure obtained by projecting the structures arranged from the moving plane to the reference plane in parallel onto the reference plane is held as a plan view 5. There is.

The instructing unit 2 sequentially inputs the two-dimensional coordinate values indicating the points where the respective current positions of the points representing the moving body are projected on the reference plane, to the determining unit 3 as the current position coordinates. Judgment unit 3
Has a line segment generation unit 6 and an intersection detection unit 7. The line segment generation unit 6 is represented by the current position coordinates input from the instruction unit 2 and the coordinates stored in the previous position storage unit. A line segment connecting the two points is generated.

The crossing detection unit 7 identifies the crossing between the parallel-projected structure of the plan view 5 and the line segment generated by the line segment generation unit 6 in the plan view 5 held in the plan view storage unit 1. Then, the presence / absence of the intersection is returned to the instruction unit 2, and the previous position storage unit 4 updates the stored contents to the current position coordinates processed by the determination unit 3.

In the second invention, the plan view storage unit 1
5 has a color designation, all the portions where the reference plane appears on the plan view are designated with a predetermined color as an identification color, and all the other portions have the color designation. When a color other than the identification color is designated and the intersection detection unit 7 identifies the intersection, there is no intersection because the color designation of the portions corresponding to all points on the line segment is the identification color. To identify.

[0014]

With the collision detecting device for a three-dimensional moving body according to the present invention,
With respect to a reference plane such as a floor surface, collision detection when a moving object moves in a movement plane parallel to the reference plane is performed using only two-dimensional data representing a plan view of a structure projected on the reference plane. Since the collision is detected by identifying the intersection of the moving path of the moving body and the obstacle, it is not necessary to identify all the obstacles in the three-dimensional space, and the collision detection process can be performed at high speed. it can.

When an observer moves inside a certain room for real-time walkthrough or the like inside a building, the observer usually moves naturally on the floor of the room,
Therefore, the viewpoint set at the position of the eyes of the observer moves in a plane parallel to the floor surface at a constant height from the floor surface.

Therefore, in the case of such a real-time walkthrough, if the viewpoint, the floor surface, and the plane on which the viewpoint moves are associated with the moving body, the reference plane, and the moving plane, respectively, a plan view. Can be used to perform collision detection.

Further, when color designation is provided in the plan view, if the color of the reference plane, for example, the floor surface is set to be a color distinguishable from other structures, the intersection identification is replaced by the color identification, Collision detection can be further speeded up by determining that all pixels on the line segment of the moving path of the viewpoint are non-collisions if they are the color of the floor surface, and even if some pixels have a color different from the floor surface, they are considered as collisions. .

[0018]

[Embodiment] FIG. 2 is a block diagram showing an embodiment of the present invention, in which the building is stored as three-dimensional data 28 according to the floor designation input by the user from the input unit 21 and the movement route designation of the pseudo observer. This is a system for performing a real-time walkthrough on the inside of a building based on the three-dimensional image data of an object and displaying on the display 29 a perspective view sequentially generated by the field-of-view setting unit 22 and the image generating unit 23.

The field-of-view setting unit 22 is used for collision detection in the movement of the observer during the real-time walkthrough.
The plan view management unit 24 and the collision detection device 30 of the present invention are connected to the.

The three-dimensional data 28 is, for example, a data which is formed by a method of approximating a curved surface with a polygonal plane of an appropriate size so that a desired image is constituted by only a large number of polygonal planes. .

In this case, the data defining each polygonal plane (hereinafter referred to as polygon data) has a fixed direction when the three-dimensional coordinates indicating the vertices of the polygon that limit the plane are viewed from the surface side of the plane. Each polygon data is conceptually represented as `` (x ₁ , y ₁ , z ₁ ), (x ₂ , y ₂ , z ₂ ), (x ₃ , y ₃ , z ₃ ), ..., color designation, ... ".

The three-dimensional coordinates are coordinates in an image space having X and Z axes in the horizontal plane and Y axis in the vertical (height) direction, and are, for example, parallel to the plane of the floor of the building constructed by the XZ axes. To do. It is assumed that the three-dimensional data 28 is configured such that a collection of such polygonal data is divided into, for example, data for each room and can be accessed.

FIG. 3 is a diagram showing an example of the overall processing flow of the real-time walkthrough processing of the system of FIG. 2. In the system of this example, the user first designates the room to be observed from the input section 21, Next, the movement path from the viewpoint of the pseudo observer (for example, one point defined as near the eye position of the person standing on the floor of the room) starting from a certain position in the specified room is sequentially specified, and the room is specified by the end specification. The observation of shall be terminated.

In FIG. 3, when the visual field setting unit 22 receives the designation input by the user from the input unit 21 in the processing step 40, the visual field setting unit 22 determines in the processing step 41 whether the designation is a room or a viewpoint. Identify whether the position and the direction of travel or the end are specified.

If a room is designated, the field-of-view setting unit 22 prepares to start the real-time walkthrough of the room in the processing step 42, for example, by a table held in advance, by the image data in the three-dimensional data 28. The address of the image data corresponding to the designated room and the three-dimensional coordinates indicating the position of the starting point of the viewpoint of the pseudo observer are identified and stored, and the address of the image data is set to a plane. The diagram management unit 24 is notified, and the collision detection device 30 is notified of the starting point position of the viewpoint.

Thereafter, the visual field setting unit 22 sets a plane parallel to the floor surface having a height determined by the Y-axis coordinate of the starting point as a moving plane, and the viewpoint moves in this moving plane until the end is designated. Process as.

In process step 43, the plan view management unit 24 passes the plan view created based on the image data of the notified room to the collision detection device 30, and the collision detection device 30 sets the plan view 35 as a plan view. It is held in the figure storage unit 31, and the starting point position of the viewpoint is stored in the front position storage unit 34, and the process returns to step 40. In addition, this plan view is the three-dimensional data as described later.
A plan view created from the image data of the room in 28 or created in advance in such a manner is stored as the plan view data 27.

When it is identified in the processing step 41 that the position of the viewpoint and the traveling direction are designated, it is identified in the processing step 44 whether the room has been designated (thus, the initial setting of the processing step 42 is completed). If the room has not been designated, an error notification is issued to the user in process step 45, and the process returns to process step 40.

If the room has been designated, in step 46,
Since the visual field setting unit 22 passes the current position coordinates of the viewpoint to the collision detection device 30 to request collision detection, the collision detection device 30
In process step 47, the collision detection process is performed using the plan view 35 as will be described later, and the result indicating the presence or absence of a collision is returned to the visual field setting unit 22.

The visual field setting unit 22 identifies the presence or absence of a collision in processing step 48. If there is no collision, the visual field setting unit 22 sets the visual field in the designated direction from the current position of the visual point, and designates the visual field in the image generation unit 23. Then, the image generation unit 23 generates a three-dimensional perspective image of the specified field of view and displays it on the display 29.

If there is a collision, processing step 50 requests the user to re-input, and the processing returns to processing step 40. When the visual field setting unit 22 identifies the end designation in the processing step 41, the control information and the like previously set in the room designation are cleared in the processing step 51, and the process returns to the processing step 40.

The above-mentioned plan view 35 used by the collision detection device 30 of the present invention for collision detection is taken from the moving plane to the reference plane with respect to the three-dimensional data 28 clipped at the moving plane, for example, data for each room. It is "two-dimensional data representing a figure in which a structure arranged up to the floor is projected in parallel onto the floor".

It is clear that such a plan view can be created from the three-dimensional data 28 by the process illustrated in FIG. 4 as follows when the floor surface is a plane of y = α and the moving plane is y = β. Is.

That is, with respect to the data of a certain room in the three-dimensional data 28, polygon data are read one by one in the processing step 52 of FIG. 4, and the vertex coordinates of each polygon data as described above are read in the processing step 53. The sequence `` (x ₁ , y ₁ , z ₁ ), (x ₂ , y ₂ , z ₂ ), (x
₃ , y ₃ , z ₃ ), ... ", the Y coordinate of each vertex is compared with β, and if the Y coordinate of all the vertices is larger than β, the entire polygon plane is above the moving plane. The polygon plane is discarded and the process returns to the processing step 52 to process the next polygon data.

If there are vertices whose Y coordinates are less than or equal to β, it is discriminated whether or not the Y coordinates of all vertices are less than or equal to β in processing step 54. If all are less than or equal to β, the entire polygonal plane is below the moving plane. In processing step 57, the data is converted into two-dimensional polygon data composed of X and Z coordinates of each vertex.

When the Y coordinate includes a vertex larger than β, in step 55, the moving plane is moved with respect to the side of the polygon connecting the vertex having the Y coordinate larger than β and the adjacent vertex having the Y coordinate smaller than β. Find the intersection with y = β.

In the processing step 56, each intersection obtained and the vertex whose Y coordinate of the original vertex is β or less are set as the vertex of the new polygon, and other color designation information inherits the original data. After the polygon data is generated, it is converted to two-dimensional polygon data in the processing step 57 in the same manner as described above.

After that, in processing step 58, it is identified whether all necessary data of the three-dimensional data 28 have been processed, and if there is any unprocessed data, the processing returns to processing step 52 to process the next polygonal data, and the two pieces of data are accumulated. A plan view is composed of three-dimensional polygon data. It should be noted that all polygons represented by the polygon data of the three-dimensional data 28 are outwardly convex polygons.

FIG. 5 is a diagram for explaining the relationship between the plan view created as described above and the image represented by the original three-dimensional data by a simple example. FIG. The stereoscopic image represented by the data, (b) is its plan view, and in (a) the shelf protrusion T1 is partly above the moving plane, so it is clipped by the moving plane, and only the lower part is clipped. (In this example, the surface shown by the diagonally shaded pattern for the purpose of explanation) is projected as T1 'in (b), and the one that is entirely under the moving plane, such as the desk-shaped protrusion T2, remains in T2. A plan is created by projecting like '.

In order to perform collision detection using the plan view created above, the line segment of the moving path of the viewpoint set as described later intersects with any of the two-dimensional polygons generated above. What to do may be detected as a collision.

That is, when the viewpoint moves on the moving plane,
In the projection on the plan view, the point a ₁ , a ₂ or a ₃ at the tip of the arrow is the current position with the point p in FIG. 5 (b) as the front position in the positional relationship with the projected figure of the obstacle. There can be three cases of position.

In those cases, as is clear from the figure, the arrow line in the case of a ₁ (corresponding to the line segment connecting the previous position and the current position of the movement route) does not intersect with any obstacle figure. It is when there is no collision.

[0043] a ₂ is a case where the current position of the viewpoint is stopped inside the obstacle figure, a ₃ is the current position is outside of the obstacle shape, a line segment connecting the current position and the previous position failure Although it is passing through the object figure, as is clear from the arrow line in the figure, there is a collision because there is an intersection with the obstacle figure (T1 ').

The detection of the intersection between the figure on the plan view and the line segment is
This can be done by calculating the intersection of the line segment of each side of each polygon represented by the two-dimensional polygon data and the line segment of the viewpoint movement route. If a color different from that of equipment is designated, and a color (or a plurality of colors) designated on the floor surface is used as an identification color, and the identification color is not used for a portion other than the floor surface, the intersection can be identified by the color.

When the intersection is identified by the color designation as described above, from the two-dimensional polygon data generated by the above processing,
Similar to the case of displaying on a display or the like, data indicating a color for each pixel is generated and used as a plan view.

In such a color designation plan view, for example, data holding color designation information corresponding to each pixel for all required pixels is arranged so that it can be indexed by pixel coordinates of each pixel. After setting the data to a certain color of the floor, update the color designation of the pixel corresponding to the polygonal area according to each 2D polygon data to the color designation specified in the 2D polygon data. It is created by going.

The correspondence between the figure represented by the two-dimensional polygon data and the pixels of the color-designed plan view is such that the coordinates of each point taken at appropriate small intervals in the figure are converted into pixel coordinates by a constant linear conversion. By doing.

FIG. 7 is a view for conceptually explaining a color designation plan view composed of such color designation data of pixels, and is a plan view of a room having a bed, a desk, a wash basin and other structures. On the floor surface that is not hidden by those structures, the color of the identification color (there are two different colors at the floor and the entrance) is designated as shown by the shaded pattern, and the part that is still white is a color other than the identification color. It is designated.

In FIG. 2, the collision detection device 30 comprises a plan view storage section 31, an instruction section 32, a determination section 33, and a front position storage section 34, and each section is a plan view storage section 1, an instruction section 2, and a front position storage section in FIG.
It corresponds to the determination unit 3 and the front position storage unit 4.

Further, the judging section 33 corresponds to the line segment generating section 6 and the intersection detecting section 7 in FIG. 1, and corresponds to the line segment generating section 36 and the intersection detecting section 37.
Consists of. FIG. 6 is a diagram showing an example of the flow of processing of the collision detection device 30, and the collision detection device 30 is supposed to perform intersection detection based on the identification color.
It is assumed that the necessary color designation of the identification color is stored in advance.

The collision detection device 30 receives the starting point position or the current position of the viewpoint from the visual field setting section 22 and starts the process in the processing step 10 of FIG. For example, when the instruction unit 32 receives the position of the viewpoint indicated by the two-dimensional coordinates of the XZ axis together with the information indicating the start point position or the current position, the information type is identified in processing step 11 to determine the start point position. In that case, the coordinate value is stored as the previous position in the previous position storage unit 34 in the processing step 12, and the process returns to the processing step 10.

If it is the current position, the current position coordinates are passed to the determination unit 33, so that the line segment generation unit 36 uses the current position coordinates and the previous position coordinates stored in the previous position storage unit 34 in processing step 13. Determine the line segment connecting the points.

For this line segment, the crossing detection unit 37 is passed to the plan view storage unit 31 from the plan view management unit 24 in plan view 35.
In order to detect the intersection of the line segment and the obstacle figure on the floor plan using (color-designed floor plan), the transformation for associating the point on the line segment with the pixel of the floor plan in the processing step 14 is performed. And check the color designation of the corresponding pixel.

In the processing step 15, the result of checking the color is identified, and if all the designated colors of the pixels corresponding to the line segment are the identification colors, the visual field setting section 22 is passed through the instruction section 32 in the processing step 16. Is notified of no collision, and in processing step 17, the memory of the previous position storage unit 34 is updated to the value of the current position of the viewpoint, and the processing step is performed.
Return to 10.

When it is determined in processing step 15 that even one pixel has a color different from the identification color in the pixels corresponding to the line segment, in processing step 18, the visual field setting unit 22 is informed that there is a collision. Notify and return to processing step 10.

[0056]

As is clear from the above description, according to the present invention, in the collision detection processing in the movement of the moving body such as the viewpoint in the real-time walkthrough, the collision detection of the moving body can be processed at high speed. Have a positive effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a flow chart of processing of an embodiment of the present invention.

FIG. 4 is a flow chart of a floor plan creation process.

FIG. 5 is a diagram illustrating a plan view.

FIG. 6 is a flowchart of processing of the collision detection device.

FIG. 7 is a diagram illustrating an example of a color designation plan view.

[Explanation of symbols]

 1, 31 Plan view storage unit 2, 32 Instruction unit 3, 33 Judgment unit 4, 34 Previous position storage unit 5, 35 Plan view 6, 36 Line segment generation unit 7, 37 Crossing detection unit 10-18, 40-58 Processing Step 21 Input section 22 Field of view setting section 23 Image generation section 24 Floor plan management section 27 Floor plan data 28 Three-dimensional data 29 Display 30 Collision detection device

Claims (2)

[Claims] 1. For a structure in a three-dimensional space represented by three-dimensional data, with respect to a reference plane set in the structure, a moving body represented by a point moving in a movement plane parallel to the reference plane. And a device for detecting a collision with a structure arranged on the reference plane, comprising a plan view storage unit (1), an instruction unit (2), a determination unit (3), and a front position storage unit. The plan view storage unit (1) has a section (4), and the three-dimensional data clipped by the moving plane, the structure arranged from the moving plane to the reference plane is used as the reference. Two-dimensional data representing a figure projected in parallel on a plane is held as a plan view (5), and the pointing unit (2) projects each current position of a point representing the moving body onto the reference plane. The two-dimensional coordinate values indicating the points are sequentially input to the determination unit (3) as the current position coordinates, and the determination unit (3) is connected to the line segment generation unit (6). An intersection detection unit (7), and the line segment generation unit (6) uses the current position coordinates input from the instruction unit (3) and the coordinates stored in the previous position storage unit (4). The intersection detecting unit (7) refers to the plan view (5) held in the plan view storage unit (1) to generate a line segment connecting the two points, and displays the parallel line of the plan view. The intersection between the projected structure and the line segment generated by the line segment generation unit (6) is identified, the presence or absence of the intersection is returned to the instruction unit (2), and the front position storage unit (4) Is a collision detection device for a three-dimensional moving body, which is configured to update the stored contents with the current position coordinates processed by the determination unit (3). 2. The plan view (5) held by the plan view storage section (1) has a color designation, and all the portions where the reference plane appears on the plan view are identified by an identification color. A predetermined color is specified, and a color other than the identification color is specified for all the other parts, and the identification of the intersection of the intersection detection unit (7) corresponds to all points on the line segment. The collision detection device for a three-dimensional moving body according to claim 1, wherein the collision designation device identifies that there is no intersection because the color designation of the portion to be performed is the identification color.