fix 'safeNormalize' (probably should remove it)

Fix for Issue 953: cull degenerate triangles
https://github.com/bulletphysics/bullet3/issues/935
Thanks to Oleg Klimov for the report and reproduction case.
This commit is contained in:
erwincoumans
2017-01-30 18:12:09 -08:00
parent 26a34e3cda
commit 72dd8285e8
4 changed files with 70 additions and 54 deletions

View File

@@ -100,45 +100,54 @@ bool SphereTriangleDetector::collide(const btVector3& sphereCenter,btVector3 &po
btScalar radiusWithThreshold = radius + contactBreakingThreshold;
btVector3 normal = (vertices[1]-vertices[0]).cross(vertices[2]-vertices[0]);
normal.safeNormalize();
btVector3 p1ToCentre = sphereCenter - vertices[0];
btScalar distanceFromPlane = p1ToCentre.dot(normal);
if (distanceFromPlane < btScalar(0.))
{
//triangle facing the other way
distanceFromPlane *= btScalar(-1.);
normal *= btScalar(-1.);
}
bool isInsideContactPlane = distanceFromPlane < radiusWithThreshold;
// Check for contact / intersection
btScalar l2 = normal.length2();
bool hasContact = false;
btVector3 contactPoint;
if (isInsideContactPlane) {
if (facecontains(sphereCenter,vertices,normal)) {
// Inside the contact wedge - touches a point on the shell plane
hasContact = true;
contactPoint = sphereCenter - normal*distanceFromPlane;
} else {
// Could be inside one of the contact capsules
btScalar contactCapsuleRadiusSqr = radiusWithThreshold*radiusWithThreshold;
btVector3 nearestOnEdge;
for (int i = 0; i < m_triangle->getNumEdges(); i++) {
btVector3 pa;
btVector3 pb;
m_triangle->getEdge(i,pa,pb);
btScalar distanceSqr = SegmentSqrDistance(pa,pb,sphereCenter, nearestOnEdge);
if (distanceSqr < contactCapsuleRadiusSqr) {
// Yep, we're inside a capsule
hasContact = true;
contactPoint = nearestOnEdge;
if (l2 >= SIMD_EPSILON*SIMD_EPSILON)
{
normal /= btSqrt(l2);
btVector3 p1ToCentre = sphereCenter - vertices[0];
btScalar distanceFromPlane = p1ToCentre.dot(normal);
if (distanceFromPlane < btScalar(0.))
{
//triangle facing the other way
distanceFromPlane *= btScalar(-1.);
normal *= btScalar(-1.);
}
bool isInsideContactPlane = distanceFromPlane < radiusWithThreshold;
// Check for contact / intersection
if (isInsideContactPlane) {
if (facecontains(sphereCenter, vertices, normal)) {
// Inside the contact wedge - touches a point on the shell plane
hasContact = true;
contactPoint = sphereCenter - normal*distanceFromPlane;
}
else {
// Could be inside one of the contact capsules
btScalar contactCapsuleRadiusSqr = radiusWithThreshold*radiusWithThreshold;
btVector3 nearestOnEdge;
for (int i = 0; i < m_triangle->getNumEdges(); i++) {
btVector3 pa;
btVector3 pb;
m_triangle->getEdge(i, pa, pb);
btScalar distanceSqr = SegmentSqrDistance(pa, pb, sphereCenter, nearestOnEdge);
if (distanceSqr < contactCapsuleRadiusSqr) {
// Yep, we're inside a capsule
hasContact = true;
contactPoint = nearestOnEdge;
}
}
}
}
}