Polygons with three corners or vertices and three sides or edges which are line segments.

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1answer
583 views

Why is my mesh generation algorithm not working properly?

I am trying to generate a grid in OpenGL ES, using known methods for triangle strips and stitching as shown in: this post and this post The code below, generates the vertices for a 4x4 grid with a ...
0
votes
4answers
681 views

Missing triangles in model

I am having an issue where triangles in a model aren't being shown. The left is wireframe, the right is the finished image. For some reason a bunch of the triangles aren't being shown. The project ...
1
vote
1answer
180 views

Drawing texture does not work anymore with a small amount of triangles

When i draw lines, the vertices are well connected. But when i draw the texture inside the triangles, it only works with i<4 in the for loop, otherwise with i<5 for example, there is a ...
4
votes
2answers
269 views

What does “kTriangles/s” mean in hardware graphics benchmark reports?

I've looked around and found several sites offering benchmarking statistics for mobile platforms and I've been seeing the unit of measure as "kTriangles/s". Originally I misread this, missing the 'k'; ...
1
vote
1answer
952 views

Opengl create tunnel TRIANGLES and texture coords on a 3d path

I have a path, lets say a bezier, or a circle. I d like to make a continously 3d cylinder (tunnel) on it (R=0.5f) How can I calculate tha TRIangles (TRIANGLE_STRIP) coordinate, and the texture ...
3
votes
4answers
215 views

Ray Triangle Intersection issue

I'm trying to perform ray triangle intersection on a mesh made of triangles. The below code seems to work fine but only about 50% of the time. The ray often gets into positions where no intersection ...
1
vote
1answer
660 views

What are the basics of 3D triangle/quad sorting?

I am really curious how any 3D engine or even the GPU sorts triangles and quads. Are they basically taking a "center" point of a particular triangle/quad/poly and then calculate a distance from a ...
3
votes
1answer
2k views

How do you split indices and vertices if their quantity goes over the limit?

I try to draw a flat surface of 500x500 squares which are built out of four vertices by two triangles. There are 1,000,000 vertices and 1,500,000 indices. The Reach profile of xna, limits primitives ...
3
votes
2answers
2k views

How does a BSP tree work for Z sorting?

I'm developing a 3D engine in software, and so I must compute Z sorting manually. I'm currently using the painters algorithm to sort triangles and then drawing them back-to-front. This causes ...
2
votes
1answer
315 views

Dynamically creating astar node map by triangular polygonal map

My game's map format uses a bunch of triangles to make up the platforms and terrain in 2d. Right now I can set up a 2d array of nodes for the astar algorithm that basically is a bunch of rectangles ...
3
votes
4answers
629 views

How to draw a line of a given length towards a given object?

I wanna draw a line between two moving objects I can't use: cDrawLine(startPointCG, endPointCG); because the line must have a length. So I'm trying to measure the angle between those two points ...
1
vote
1answer
199 views

How to optimize primitives in SecondLife/Opensim?

SecondLife/Opensim uses Primitives to construct models. How it works in details is explained here. Now I have many triangles which link together. Is there any way to make them into one prim, thus ...
4
votes
3answers
5k views

Triangle - Rectangle Intersection in 2D

I had previously asked this for 3D but now I changed my strategy and would like to do the intersection in 2D. The Rectangle is axis aligned and will always be in a fixed position, and has a constant ...
3
votes
1answer
3k views

Triangle-Plane intersection in 3D space

I would like to clip a triangle if its bounds lie partially out of a cube for this I guess I would need some kind of Triangle Plane intersection code, I'm not well versed with math but I do have the ...
10
votes
1answer
1k views

Triangulation A* (TA*) pathfinding algorithm

I need help understanding the Triangle A* (TA*) algorithm that is described by Demyen in his paper Efficient Triangulation-Based Pathfinding, on pages 76-81. He describes how to adapt the regular A* ...
3
votes
1answer
1k views

Ray-plane intersection to find the Z of the intersecting point

I have a rectangle in 3d space (p1, p2, p3, p4) and when the mouse rolls over it I need to calculate the exact Z of the point on the rect, given the mouse coordinates (x, y). Would a Ray-plane ...