Open Gpinchon opened 2 weeks ago
Why no point size extension?
Because there were no specific proposals. It's likely that apps that need to better define point rendering use their private extensions or other means to deliver that information.
To make it a "proper" KHR extension, many non-obvious issues would need to be addressed. What works for one application may be too much or not enough for others. For example:
I could be interrested by making such proposal specifically for points size, but I don't know where to start... As for the issues you raised, here are my suggestions
gl_PointSize=perPrimitive*perVertex
Some random suggestions here:
gl_PointCoord
or similar, such that the points can be textured.VkPolygonMode
for Vulkan, D3DPRIMITIVETYPE
for DirectX and draw modes for OpenGL... Though now that I'm talking about other APIs I realize that glPointSize
is quite unique and has no equivalents on VK or DX, DirectX not even allowing variable point size AFAIK (though that can be "fixed" via geometry shaders). Nevertheless, point size seems to be a vertex property, having materials influence vertex shaders seems intuitively kind of odd to me.
Having no way of specifying point size is kind of a problem when using GLTF to share datasets. When we want to use points to render a "surface" or "volumetric" surface there is no way to adjust for point density in order to get consistent rendering. A good example of the issue I'm facing with point clouds would be the difference you get in term of rendering with this model with high density vs this model with low density.