// "This template is instantiated on a per-mesh basis. Within a mesh, a sequence of n
// instances of this template will appear, where n is the number of bones (X file frames)
// that influence the vertices in the mesh. Each instance of the template basically defines
// the influence of a particular bone on the mesh. There is a list of vertex indices, and a
// corresponding list of weights.
// template SkinWeights
// {
// STRING transformNodeName;
// DWORD nWeights;
// array DWORD vertexIndices[nWeights];
// array float weights[nWeights];
// Matrix4x4 matrixOffset;
// }
// - The name of the bone whose influence is being defined is transformNodeName,
// and nWeights is the number of vertices affected by this bone.
// - The vertices influenced by this bone are contained in vertexIndices, and the weights for
// each of the vertices influenced by this bone are contained in weights.
// - The matrix matrixOffset transforms the mesh vertices to the space of the bone. When concatenated
// to the bone's transform, this provides the world space coordinates of the mesh as affected by the bone."
// (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/
// directx9_c/dx9_graphics_reference_x_file_format_templates.asp)
//
// Reads in a bone that contains skin weights. It then adds one bone weight
// to every vertex that is influenced by ths bone, which contains the name of the bone and the
// weight.
public void ImportSkinWeights()
{
isSkinned = true;
string boneName = tokens.SkipName().NextString();
// an influence is an index to a vertex that is affected by the current bone
int numInfluences = tokens.NextInt();
List <int> influences = new List <int>();
List <float> weights = new List <float>();
for (int i = 0; i < numInfluences; i++)
{
influences.Add(tokens.NextInt());
}
for (int i = 0; i < numInfluences; i++)
{
weights.Add(tokens.NextFloat());
if (weights[i] == 0)
{
influences[i] = -1;
}
}
influences.RemoveAll(delegate(int i) { return(i == -1); });
weights.RemoveAll(delegate(float f) { return(f == 0); });
// Add the matrix that transforms the vertices to the space of the bone.
// we will need this for skinned animation.
Matrix blendOffset = tokens.NextMatrix();
ContentUtil.ReflectMatrix(ref blendOffset);
skinTransformDictionary.Add(boneName, blendOffset);
SkinTransformContent trans = new SkinTransformContent();
trans.BoneName = boneName;
trans.Transform = blendOffset;
skinTransforms.Add(trans);
// end of skin weights
tokens.SkipToken();
// add a new name/weight pair to every vertex influenced by the bone
for (int i = 0; i < influences.Count; i++)
{
skinInfo[influences[i]].Add(new BoneWeight(boneName,
weights[i]));
}
}
/// <summary>
/// Converts the bone weight collections into working vertex channels by using the
/// provided bone index dictionary. Converts bone names into indices.
/// </summary>
/// <param name="boneIndices">A dictionary that maps bone names to their indices</param>
public void AddWeights(Dictionary <string, int> boneIndices)
{
if (!isSkinned)
{
return;
}
Dictionary <string, int> meshBoneIndices = new Dictionary <string, int>();
int currentIndex = 0;
// The bone indices are already sorted by index
foreach (KeyValuePair <string, int> k in boneIndices)
{
if (skinTransformDictionary.ContainsKey(k.Key))
{
meshBoneIndices.Add(k.Key, currentIndex++);
SkinTransformContent transform = new SkinTransformContent();
transform.BoneName = k.Key;
transform.Transform = skinTransformDictionary[k.Key];
skinTransforms.Add(transform);
}
}
}