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> The quads weren't even that big of a problem. Even if the industry did standardise on triangles for 3D hardware, a lot of the artist pipelines sick with quads

> The quads weren't even that big of a problem. Even if the industry did standardise on triangles for 3D hardware, a lot of the artist pipelines sick with quads as much as possible. AFAIK the problems lie in things like clipping/collision detection. Now that you have four points instead of three, there is no guarantee that the polygon is a flat surface.

cubefox 3y ago
That's interesting. I always wondered why "polygons" generally ended up being triangles. I guess this is of the reasons.
- MBCook 3y ago
  That’s one part, and it’s big. I believe the other part is that triangle strips are more efficient because they can share vertices better than quad strips.
  - cubefox 3y ago
    Of course, but that's not generally true. Why use two triangles for e.g. a rectangular floor? The walls and the ceiling are also rectangular after all. Probably mixing and matching different polygons isn't very efficient either. About collision: I don't know how it is computed, but if it's by ray casting, that is now also used for lighting effects and sometimes reflections. Which would be another reason to stick to triangles.
    - mmaniac 3y ago
      The Playstation, at least, supports quads as a draw primitive. It does decompose these quads to tris for rasterization[1]. The Nintendo DS actually supports both tris and quads as rasterization primitives, which has some interesting consequences for shading[2]. [1] https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#gpu-render-polygon-commands https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#gp... [2] https://melonds.kuribo64.net/comments.php?id=13 https://melonds.kuribo64.net/comments.php?id=13
phire 3y ago
That's not a massive problem. Most games avoid using the same meshes for both rendered graphics and collision detection. Collision detection is usally done against a simplified mesh with much fewer polygons. Since most games already already have two meshes, there isn't a problem making one mesh out of quads and the other out of triangles.

cubefox 3y ago

That's interesting. I always wondered why "polygons" generally ended up being triangles. I guess this is of the reasons.

MBCook 3y ago
That’s one part, and it’s big. I believe the other part is that triangle strips are more efficient because they can share vertices better than quad strips.
- cubefox 3y ago
  Of course, but that's not generally true. Why use two triangles for e.g. a rectangular floor? The walls and the ceiling are also rectangular after all. Probably mixing and matching different polygons isn't very efficient either. About collision: I don't know how it is computed, but if it's by ray casting, that is now also used for lighting effects and sometimes reflections. Which would be another reason to stick to triangles.
  - mmaniac 3y ago
    The Playstation, at least, supports quads as a draw primitive. It does decompose these quads to tris for rasterization[1]. The Nintendo DS actually supports both tris and quads as rasterization primitives, which has some interesting consequences for shading[2]. [1] https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#gpu-render-polygon-commands https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#gp... [2] https://melonds.kuribo64.net/comments.php?id=13 https://melonds.kuribo64.net/comments.php?id=13

phire 3y ago

That's not a massive problem. Most games avoid using the same meshes for both rendered graphics and collision detection. Collision detection is usally done against a simplified mesh with much fewer polygons. Since most games already already have two meshes, there isn't a problem making one mesh out of quads and the other out of triangles.