The computational-geometry tag has no wiki summary.
3
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1answer
133 views
Procedural Geometry Generation
I have recently been looking into SceneKit for OS X and noticed that there are several factory methods to create geometric shapes such as:
Box, Capsule, Cone, Cylinder, Plane, Pyramid, Sphere, Torus ...
2
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2answers
75 views
How scanline rendering finds an intersection with an object
I'm a newbie with graphics and after I read many articles on the web I still don't understand how in rasterizing from a pixel coordinate like (0;0) on the screen the intersection with an object (let's ...
1
vote
2answers
322 views
How to create a walkable 3D terrain
I want to make a terrain for a RPG game that I'm developing. I started modeling the surface and implementing it to my game, but now I realized that i might be doing everything wrong. So I would like ...
0
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1answer
189 views
Fast software color interpolating triangle rasterization technique
I'm implementing a software renderer with this rasterization method, however, I was wondering if there is a possibility to improve it, or if there exists an alternative technique that is much faster. ...
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0answers
184 views
Annoying flickering of vertices and edges (possible z-fighting)
I'm trying to make a software z-buffer implementation (meaning no DirectX or OpenGL, only a 2D library, SDL to be precise), however, after I generate the z-buffer and proceed with the vertex culling, ...
0
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1answer
134 views
Scanline filling of polygons that share edges and vertices
In this picture (a perspective projection of an icosahedron), the scanline (red) intersects that vertex at the top. In an icosahedron each edge belongs to two triangles. From edge a, only one triangle ...
3
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2answers
328 views
Scan-Line Z-Buffering Dilemma
I have a set of vertices in 3D space, and for each I retain the following information:
Its 3D coordinates (x, y, z).
A list of pointers to some of the other vertices with which it's connected by ...
0
votes
1answer
343 views
Easy way to project point onto triangle (or plane)
I have a mesh of triangles (navigation mesh), and a point in 3d space. This point should be "over" one of the triangles all the times. I'm trying to determine which triangle is the one the point is ...
1
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2answers
311 views
Segment-Cylinder intersection
What is the complete code (C#, pseudo, does not matter) for calculating the resulting segment (or its absence) for the intersection of the segment and the cylinder?
The segment is defined by ...
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0answers
90 views
Some good reading on polygon algorithms [closed]
What are some good resources (books, articles, sites) about polygon intersection and union algorithms?
1
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6answers
307 views
Testing whether two cubes are touching in space
Does anyone have any clean ideas on testing whether two cubes in 3D space touch? By touch I mean, touch at corners or on a face or on an edge. Say that the cubes are axis aligned and there is no ...
1
vote
2answers
163 views
How do i calc what side the ball is of the rect?
I have this nice drawing:
http://bildr.no/view/1085283
I know the ball's center and the rectangle's center, but how do I know (programming C#) what side of the rectangle the ball is?
By my drawing, ...
2
votes
4answers
1k views
What is an efficient 2D line-segment-versus-triangle intersection test?
In a 2D plane, I have a line segment (P0 and P1) and a triangle, defined by three points (t0, t1 and t2).
My goal is to test, as efficiently as possible ( in terms of computational time), whether the ...
2
votes
1answer
264 views
Determine the cut sections of a polygonal mesh
I have a polygonal mesh, defined by vertices $V$, edges $E$ and face $F$. One can view this as a real life 3D terrain.
I want to obtain cut sections of this terrain, defined by vertical cut planes. ...
14
votes
1answer
557 views
How to resolve collisions of compound shapes using SAT?
SAT is a decent way to determine collisions between arbitrary convex polygons. You'll even get the vector that is needed to resolve a collision.
To resolve collisions between complex (non-convex) ...
3
votes
2answers
224 views
How to generate slopes that meet the plane, is using collision detection a good idea?
I have a terrain, which is defined by mesh. And there are a lot of other polygonal faces scattered throughout the terrain, they can be located above, or below or cutting through the terrain. You can ...
13
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2answers
2k views
How to find if circle and concave polygon intersect?
I have a polygon (sometimes convex, but often concave), and a bunch of circles with different radius. How can I find out if a circle is intersecting/overlapping with the polygon?
If it makes it ...
4
votes
3answers
915 views
Point line collision reaction
I am trying to program point line segment collision detection and reaction. I am doing this for fun and to learn.
The point moves (it has a velocity, and can be controlled by the user), whilst the ...
