GPU Skinning Problem

B. / · 2018-03-09T17:20:55

Hello, I have a Problem with GPU Skinning, I load from a COLLADA File my object with the vertices and the weights and bone indices for it and the bones with the matrices. For every vertex I choose 4 weights and 4 bone indices. For every non skin vertex i choose by the weights 1 0 0 0 and bone indices 0 0 0 0 (In the Bone Matrices Array is index 0 a Matrix Idetity) And i check up if all weights values together is always 1 or i calculate it to 1. So far so good, my Shader looks like this: bool HasBones; matrix BoneMatrices[256]; struct Vertex { float3 Position : POSITION; float3 Normal : NORMAL; float2 UV : TEXCOORD0; float3 Tangent : TANGENT; float4 Weights : WEIGHTS; int4 BoneIndices : BONEINDICES; }; float4 ApplyBoneTransform(Vertex input, float4 value) { if(HasBones) { float4x4 skinTransform = (float4x4)0; skinTransform += BoneMatrices[input.BoneIndices.x] * input.Weights.x; skinTransform += BoneMatrices[input.BoneIndices.y] * input.Weights.y; skinTransform += BoneMatrices[input.BoneIndices.z] * input.Weights.z; skinTransform += BoneMatrices[input.BoneIndices.w] * input.Weights.w; float4 position = mul(value, skinTransform); return position; } else return value; } Pixel vertexShader(Vertex input) { Pixel result = (Pixel) 0; float4 posWorld = mul(ApplyBoneTransform(input, float4(input.Position.xyz, 1.0f)), World); result.Position = mul(mul(posWorld, View), Projection); result.Normal = normalize(mul(ApplyBoneTransform(input, float4(input.Normal.xyz, 1.0f)), WorldIT)); result.UV = input.UV; result.View = ViewInverse[3] - mul(float4(input.Position.xyz, 1.0f), World); result.Tangent = normalize(mul(ApplyBoneTransform(input, float4(input.Tangent.xyz, 1.0f)), WorldIT).xyz); result.Binormal = normalize(cross(input.Normal, input.Tangent)); return result; } And if i set HasBones to true, my object will not draw right anymore, i only see two dark triangles I believe it depends on the bone matrices i load from the controller_lib of the COLLADA File and send it to the BoneMatrices in the shader + at the index 0 the Matrix Idetity. Has anyone an Idea what I make wrong and could help and explain me it? And i upload to this post the Collada file and images of the object draw in HasBones = false and HasBones = true Greets Benajmin Model.dae

Graphics and GPU Programming Programming DX11

Started by B. / February 03, 2018 06:41 PM

38 comments, last by B. / 6 years, 11 months ago

B. /

Author

March 09, 2018 05:20 PM

I know it's a little bit late, but better late as never

I figure out for a couple of weeks how to handle my problem

For a correct Animation play you need to send the Shader the InverseSourceSpace you load from the COLLADA FILE * the and the calculate world target space as bone matrices. You calculate bone world space from all the local space of the bone hierarchy and if you have animations on a bone you take the aniamtion matrix instead of the local matrix of the bone

And in the shader you need to multipy the vertex 1. with the bindposematrix, 2. with the skin transform matrix and 3. with the world matrix and everything works correct

I post this description to say thank you to the gamedev community and especially to JoeJ and turanszkij that you helped me with my problem and bring me in the right direction for the solution

Greets

Benjamin

GPU Skinning Problem

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GPU Skinning Problem

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