void WriteIndices(Mesh assimpMesh, ModelData.MeshPart meshPart, ModelData.IndexBuffer indexBuffer)
{
// Write all indices
var indices = assimpMesh.GetIntIndices();
indexBuffer.Count = indices.Length;
meshPart.IndexBufferRange.Count = indices.Length;
if (meshPart.VertexBufferRange.Count < 65536)
{
// Write only short indices if count is less than the size of a short
indexBuffer.Buffer = new byte[indices.Length * 2];
using (var indexStream = DataStream.Create(indexBuffer.Buffer, true, true))
foreach (int index in indices)
{
indexStream.Write((ushort)index);
}
}
else
{
// Otherwise, use full 32-bit precision to store indices
indexBuffer.Buffer = new byte[indices.Length * 4];
using (var indexStream = DataStream.Create(indexBuffer.Buffer, true, true))
indexStream.WriteRange(indices);
}
// Update the MaximumBufferSizeInBytes needed to load this model
if (indexBuffer.Buffer.Length > model.MaximumBufferSizeInBytes)
{
model.MaximumBufferSizeInBytes = indexBuffer.Buffer.Length;
}
}
private ModelData.MeshPart Process(ModelData.Mesh mesh, Mesh assimpMesh)
{
var meshPart = new ModelData.MeshPart
{
PrimitiveTopology = PrimitiveTopology.TriangleList,
VertexBufferRange = new ModelData.BufferRange {
Slot = mesh.VertexBuffers.Count
},
IndexBufferRange = new ModelData.BufferRange {
Slot = mesh.IndexBuffers.Count
}
};
var vertexBuffer = new ModelData.VertexBuffer
{
Layout = new List <VertexElement>()
};
mesh.VertexBuffers.Add(vertexBuffer);
var indexBuffer = new ModelData.IndexBuffer();
mesh.IndexBuffers.Add(indexBuffer);
var layout = vertexBuffer.Layout;
int vertexBufferElementSize = 0;
// Add position
layout.Add(VertexElement.PositionTransformed(Format.R32G32B32_Float, 0));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector3>();
// Add normals
if (assimpMesh.HasNormals)
{
layout.Add(VertexElement.Normal(0, Format.R32G32B32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector3>();
}
// Add colors
if (assimpMesh.VertexColorChannelCount > 0)
{
for (int localIndex = 0, i = 0; i < assimpMesh.VertexColorChannelCount; i++)
{
if (assimpMesh.HasVertexColors(i))
{
layout.Add(VertexElement.Normal(localIndex, Format.R32G32B32A32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Color4>();
localIndex++;
}
}
}
// Add textures
if (assimpMesh.TextureCoordsChannelCount > 0)
{
for (int localIndex = 0, i = 0; i < assimpMesh.TextureCoordsChannelCount; i++)
{
if (assimpMesh.HasTextureCoords(i))
{
var uvCount = assimpMesh.GetUVComponentCount(i);
if (uvCount == 2)
{
layout.Add(VertexElement.TextureCoordinate(localIndex, Format.R32G32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector2>();
}
else if (uvCount == 3)
{
layout.Add(VertexElement.TextureCoordinate(localIndex, Format.R32G32B32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector3>();
}
else
{
throw new InvalidOperationException("Unexpected uv count");
}
localIndex++;
}
}
}
if (options.ModelOperations.HasFlag(ModelOperation.CalculateBarycentricCoordinates))
{
layout.Add(new VertexElement("BARYCENTRIC", 0, Format.R32G32B32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector3>();
}
else
// Add tangent / bitangent
if (assimpMesh.HasTangentBasis)
{
if (!options.ExcludeElements.Contains("Tangent"))
{
layout.Add(VertexElement.Tangent(Format.R32G32B32A32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector4>();
}
if (!options.ExcludeElements.Contains("BiTangent"))
{
layout.Add(VertexElement.BiTangent(Format.R32G32B32_Float, vertexBufferElementSize));
vertexBufferElementSize += SharpDX.Utilities.SizeOf <Vector3>();
}
}
if (options.ModelOperations.HasFlag(ModelOperation.CalculateBarycentricCoordinates))
{
WriteBarycentricVertices(assimpMesh, meshPart, vertexBuffer, vertexBufferElementSize);
}
else
{
WriteVertices(assimpMesh, meshPart, vertexBuffer, vertexBufferElementSize);
}
WriteIndices(assimpMesh, meshPart, indexBuffer);
return(meshPart);
}
