void SkeletonModel::computeBoundingShape(const FBXGeometry& geometry) {
// compute default joint transforms
int numStates = _jointStates.size();
QVector<glm::mat4> transforms;
transforms.fill(glm::mat4(), numStates);
QVector<VerletPoint>& ragdollPoints = _ragdoll->getPoints();
// compute the default transforms and slam the ragdoll positions accordingly
// (which puts the shapes where we want them)
for (int i = 0; i < numStates; i++) {
JointState& state = _jointStates[i];
const FBXJoint& joint = state.getFBXJoint();
int parentIndex = joint.parentIndex;
if (parentIndex == -1) {
transforms[i] = _jointStates[i].getTransform();
ragdollPoints[i].initPosition(extractTranslation(transforms[i]));
continue;
}
glm::quat modifiedRotation = joint.preRotation * joint.rotation * joint.postRotation;
transforms[i] = transforms[parentIndex] * glm::translate(joint.translation)
* joint.preTransform * glm::mat4_cast(modifiedRotation) * joint.postTransform;
// setting the ragdollPoints here slams the VerletShapes into their default positions
ragdollPoints[i].initPosition(extractTranslation(transforms[i]));
}
// compute bounding box that encloses all shapes
Extents totalExtents;
totalExtents.reset();
totalExtents.addPoint(glm::vec3(0.0f));
for (int i = 0; i < _shapes.size(); i++) {
Shape* shape = _shapes[i];
if (!shape) {
continue;
}
// TODO: skip hand and arm shapes for bounding box calculation
Extents shapeExtents;
shapeExtents.reset();
glm::vec3 localPosition = shape->getTranslation();
int type = shape->getType();
if (type == CAPSULE_SHAPE) {
// add the two furthest surface points of the capsule
CapsuleShape* capsule = static_cast<CapsuleShape*>(shape);
glm::vec3 axis;
capsule->computeNormalizedAxis(axis);
float radius = capsule->getRadius();
float halfHeight = capsule->getHalfHeight();
axis = halfHeight * axis + glm::vec3(radius);
shapeExtents.addPoint(localPosition + axis);
shapeExtents.addPoint(localPosition - axis);
totalExtents.addExtents(shapeExtents);
} else if (type == SPHERE_SHAPE) {
float radius = shape->getBoundingRadius();
glm::vec3 axis = glm::vec3(radius);
shapeExtents.addPoint(localPosition + axis);
shapeExtents.addPoint(localPosition - axis);
totalExtents.addExtents(shapeExtents);
}
}
// compute bounding shape parameters
// NOTE: we assume that the longest side of totalExtents is the yAxis...
glm::vec3 diagonal = totalExtents.maximum - totalExtents.minimum;
// ... and assume the radius is half the RMS of the X and Z sides:
float capsuleRadius = 0.5f * sqrtf(0.5f * (diagonal.x * diagonal.x + diagonal.z * diagonal.z));
_boundingShape.setRadius(capsuleRadius);
_boundingShape.setHalfHeight(0.5f * diagonal.y - capsuleRadius);
glm::vec3 rootPosition = _jointStates[geometry.rootJointIndex].getPosition();
_boundingShapeLocalOffset = 0.5f * (totalExtents.maximum + totalExtents.minimum) - rootPosition;
_boundingRadius = 0.5f * glm::length(diagonal);
}
