FUBoundingSphere FUBoundingSphere::Transform(const FMMatrix44& transform) const
{
if (!IsValid()) return (*this);
FMVector3 transformedCenter = transform.TransformCoordinate(center);
FUBoundingSphere transformedSphere(transformedCenter, 0.0f);
// Calculate the transformed bounding sphere radius using three sample points.
FMVector3 testPoints[3] =
{
FMVector3(radius, 0.0f, 0.0f),
FMVector3(0.0f, radius, 0.0f),
FMVector3(0.0f, 0.0f, radius)
};
for (size_t i = 0; i < 6; ++i)
{
testPoints[i] = transform.TransformVector(testPoints[i]);
float lengthSquared = testPoints[i].LengthSquared();
if (lengthSquared > transformedSphere.radius * transformedSphere.radius)
{
transformedSphere.radius = sqrtf(lengthSquared);
}
}
return transformedSphere;
}
/**
* Applies world-space transform to vertex data and transforms Collada's right-handed
* Y-up / Z-up coordinates to the game's left-handed Y-up coordinate system
*/
static void TransformStaticModel(float* position, float* normal, size_t vertexCount,
const FMMatrix44& transform, bool yUp)
{
for (size_t i = 0; i < vertexCount; ++i)
{
FMVector3 pos (&position[i*3], 0);
FMVector3 norm (&normal[i*3], 0);
// Apply the scene-node transforms
pos = transform.TransformCoordinate(pos);
norm = FMVector3_Normalize(transform.TransformVector(norm));
// Convert from right-handed Y_UP or Z_UP to the game's coordinate system (left-handed Y-up)
if (yUp)
{
pos.z = -pos.z;
norm.z = -norm.z;
}
else
{
std::swap(pos.y, pos.z);
std::swap(norm.y, norm.z);
}
// Copy back to array
position[i*3] = pos.x;
position[i*3+1] = pos.y;
position[i*3+2] = pos.z;
normal[i*3] = norm.x;
normal[i*3+1] = norm.y;
normal[i*3+2] = norm.z;
}
}
/**
* Applies world-space transform to vertex data and transforms Collada's right-handed
* Y-up / Z-up coordinates to the game's left-handed Y-up coordinate system
*/
static void TransformSkinnedModel(float* position, float* normal, size_t vertexCount,
std::vector<BoneTransform>& bones, std::vector<PropPoint>& propPoints,
const FMMatrix44& transform, const FMMatrix44& bindTransform, bool yUp, bool isXSI)
{
FMMatrix44 scaledTransform; // for vertexes
FMMatrix44 scaleMatrix; // for bones
// HACK: see comment in PSAConvert::TransformVertices
if (isXSI)
{
scaleMatrix = DecomposeToScaleMatrix(transform);
scaledTransform = DecomposeToScaleMatrix(bindTransform) * transform;
}
else
{
scaleMatrix = FMMatrix44_Identity;
scaledTransform = bindTransform;
}
// Update the vertex positions and normals
for (size_t i = 0; i < vertexCount; ++i)
{
FMVector3 pos (&position[i*3], 0);
FMVector3 norm (&normal[i*3], 0);
// Apply the scene-node transforms
pos = scaledTransform.TransformCoordinate(pos);
norm = FMVector3_Normalize(scaledTransform.TransformVector(norm));
// Convert from right-handed Y_UP or Z_UP to the game's coordinate system (left-handed Y-up)
if (yUp)
{
pos.z = -pos.z;
norm.z = -norm.z;
}
else
{
std::swap(pos.y, pos.z);
std::swap(norm.y, norm.z);
}
// and copy back into the original array
position[i*3] = pos.x;
position[i*3+1] = pos.y;
position[i*3+2] = pos.z;
normal[i*3] = norm.x;
normal[i*3+1] = norm.y;
normal[i*3+2] = norm.z;
}
TransformBones(bones, scaleMatrix, yUp);
// And do the same for prop points
for (size_t i = 0; i < propPoints.size(); ++i)
{
if (yUp)
{
propPoints[i].translation[0] = -propPoints[i].translation[0];
propPoints[i].orientation[0] = -propPoints[i].orientation[0];
propPoints[i].orientation[3] = -propPoints[i].orientation[3];
}
else
{
// Flip translation across the x-axis by swapping y and z
std::swap(propPoints[i].translation[1], propPoints[i].translation[2]);
// To convert the quaternions: imagine you're using the axis/angle
// representation, then swap the y,z basis vectors and change the
// direction of rotation by negating the angle ( => negating sin(angle)
// => negating x,y,z => changing (x,y,z,w) to (-x,-z,-y,w)
// but then (-x,-z,-y,w) == (x,z,y,-w) so do that instead)
std::swap(propPoints[i].orientation[1], propPoints[i].orientation[2]);
propPoints[i].orientation[3] = -propPoints[i].orientation[3];
}
}
}