The computational-geometry tag has no wiki summary.
2
votes
2answers
30 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
283 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
votes
1answer
168 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. ...
2
votes
0answers
171 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
votes
1answer
128 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
votes
2answers
307 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
0answers
83 views
Wrapping polyhedral of a mesh
I have an object with a mesh which has 6 faced semi-cubic elements, and I want to draw it with OpenGL.
But, since I do not need transparency, I just need to draw the polyhedral that wraps my object, ...
0
votes
1answer
329 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
vote
2answers
289 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 ...
0
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0answers
89 views
Some good reading on polygon algorithms [closed]
What are some good resources (books, articles, sites) about polygon intersection and union algorithms?
1
vote
6answers
300 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
156 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
983 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
250 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
527 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) ...
