const Vec3 Positionable::position() const
{
Vec4 position = m_transformationMatrix * Vec4(0,0,0,1);
Vec3 resultPosition(position.x, position.y, position.z);
return resultPosition;
}
void Model::draw(unsigned int animation, double timeIn)
{
if (scene->mNumAnimations <= animation)
return;
aiAnimation* currentAnimation = scene->mAnimations[animation];
//Step 1: Interpolate position, rotation, scale in the all channels and add to transformation
for (unsigned int i = 0; i < currentAnimation->mNumChannels; i++)
{
aiNodeAnim* currentChannel = currentAnimation->mChannels[i];
aiVector3D currentPosition = interpolatePosition(currentChannel, timeIn);
aiQuaternion currentRotation = interpolateRotation(currentChannel, timeIn);
aiVector3D currentScale = interpolateScale(currentChannel, timeIn);
aiMatrix4x4& transformation = aiMatrix4x4(currentScale, currentRotation, currentPosition);
aiNode* currentNode = scene->mRootNode->FindNode(currentChannel->mNodeName);
currentNode->mTransformation = transformation;
}
for (unsigned int k = 0; k < scene->mNumMeshes; k++)
{
//Step 2: Bone transformation, change transformation of the bone according to animation
aiMesh* currentMesh = scene->mMeshes[k];
std::vector<aiMatrix4x4> boneTransformations = std::vector<aiMatrix4x4>(currentMesh->mNumBones);
for (unsigned int i = 0; i < currentMesh->mNumBones; i++)
{
aiBone* currentBone = currentMesh->mBones[i];
aiNode* currentNode = scene->mRootNode->FindNode(currentBone->mName);
boneTransformations[i] = parentMultiplication(currentNode);
boneTransformations[i] *= currentMesh->mBones[i]->mOffsetMatrix;
}
//Step 3: Skinning
std::vector<aiVector3D> resultPosition(currentMesh->mNumVertices);
for (size_t k = 0; k < currentMesh->mNumBones; k++)
{
const aiBone* currentBone = currentMesh->mBones[k];
const aiMatrix4x4& positionMatrix = boneTransformations[k];
for (size_t j = 0; j < currentBone->mNumWeights; j++)
{
const aiVertexWeight& weight = currentBone->mWeights[j];
size_t vertexId = weight.mVertexId;
const aiVector3D& srcPosition = currentMesh->mVertices[vertexId];
resultPosition[vertexId] += weight.mWeight * (positionMatrix * srcPosition);
}
}
//Step 4: Draw the final model
// For every face
size_t cv = 0, ctc = 0;
glColor3d(1.0, 1.0, 1.0); // Set the face color to white
for (int cf = 0; cf < currentMesh->mNumFaces; cf++)
{
const aiFace& face = currentMesh->mFaces[cf];
// For all vertices in face (Final drawing)
if (wireframe)
glBegin(GL_LINE_LOOP);
else
glBegin(GL_TRIANGLES);
for (int cfi = 0; cfi < 3; cfi++)
{
double x = resultPosition[face.mIndices[cfi]].x;
double y = resultPosition[face.mIndices[cfi]].y;
double z = resultPosition[face.mIndices[cfi]].z;
glVertex3d(x, y, z);
}
glEnd();
}
}
}
