调度超过 65535 个线程
我正在尝试使用 DirectCompute 对顶点进行蒙皮。所采用的蒙皮方法使得您可以拥有影响每个顶点的可变数量的权重（例如，Md5 网格就是以这种方式定义的）。
基本上计算着色器的输入是。
JointsBuffer { float4 orientation, float4 position } Structured buffer SRV
WeightsBuffer { float3 normal, float4 position, float bias, uint jointIndex } Structured buffer SRV
VerticesBuffer { float2 texcoords, uint weightIndex, uint numWeights } Structured buffer SRV
现在，
SkinnedVerticesBuffer { float3 normal, float4 position, float2 texcoord } Structured buffer UAV
计算着色器应该为顶点缓冲区中的每个元素运行一次，并使用 SV_DispatchThreadID，着色器尝试为 VerticesBuffer 中的每个顶点填充 SkinnedVerticesBuffer 中相应的 SkinnedVertex（1:1 对应关系）。
因此，问题在于许多网格体的顶点数超过 65535 个，而 DispatchThreadID 命令只允许为每个维度分派那么多线程。现在我理论上可以写一些东西，将很多数字分成小于 65535 的三个因数的组合，但对于质数我不可能做到这一点。
因此，例如，当出现一些具有 71993 个（质数）顶点的网格时，我想不出处理它的方法。
我不能过度调度 72000 个带有 context->Dispatch( 36000, 2, 0 ) 的线程，因为这样 DispatchThreadID 将超出我的缓冲区范围。
现在我倾向于使用一个恒定的缓冲区来保存顶点的数量，然后过度调度到最接近的2的幂，然后简单地做
if( SV_DispatchThreadID > numVertices ) return;
这是我唯一的选择吗？其他人都会遇到这个障碍。
I'm attempting to skin vertices using DirectCompute. The method of skinning employed is such that you can have a variable amount of weights influencing each vertex (e.g. Md5 meshes are defined this way).
Basically inputs to the compute shader are.
JointsBuffer { float4 orientation, float4 position } Structured buffer SRV
WeightsBuffer { float3 normal, float4 position, float bias, uint jointIndex } Structured buffer SRV
VerticesBuffer { float2 texcoords, uint weightIndex, uint numWeights } Structured buffer SRV
and the output is
SkinnedVerticesBuffer { float3 normal, float4 position, float2 texcoord } Structured buffer UAV
Now the compute shader should be run once per element in the vertex buffer, and using SV_DispatchThreadID the shader attempts to populate the corresponding SkinnedVertex in the SkinnedVerticesBuffer for every Vertex in the VerticesBuffer ( 1:1 correspondence ).
So the problem is that many meshes have greater than 65535 vertices, and the DispatchThreadID command only allows for dispatching that many threads per dimension. Now I can theoretically write something that divides a lot of numbers up into a combination of three factors less than 65535, but I can't possibly do that for prime numbers.
So for example when some mesh with 71993 ( a prime number ) of vertices comes up I can't think of a way to handle it.
I can't over dispatch say 72000 threads with context->Dispatch( 36000, 2, 0 ), because then DispatchThreadID will run out of my buffer bounds.
Right now I'm leaning towards a constant buffer holding the amount of vertices, and then over dispatching to the nearest power of 2 and then simply doing
if( SV_DispatchThreadID > numVertices ) return;
Is this my only option? Anyone else run into this snag.
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我从来没有。但 65000 个线程似乎太多了。
然后，当我尝试查找 文档 看来你传递的值不是线程，而是线程组。 gamedev 上的某人在通过时似乎存在性能问题一个像 768 这样大的数字，所以在我看来，你必须减少这个巨大的数字。
我不确定，但我感觉你误解了这些参数。尝试再次阅读这些值的实际含义。 （不过，这只是外行人的直觉。）
I've never. But 65000 threads seems like an awful lot.
Then, when I try to find documentation it seems that the values you pass are not threads, but thread groups. Someone on gamedev seems to have performance issues when passing a number as great as 768, so it seems to me that you will have to decrease that huge number.
I'm not sure, but I got the feeling you're misinterpreting these parameters. Try to read again what these values actually mean. (Just a layman's gut feeling, though.)