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perform GrahamScanConvexHull2D around an arbitrary oriented 2D plane in 3D, to fix some convex hull face merging problems

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add compound shape support to BulletXmlWorldImporter and fix some compile issue under Debian (hopefully)
object picking change in the demos: create a ball-socket picking constraint when holding shift while mouse dragging, otherwise a fixed (6dof) constraint
add assert in constraint solver, when both objects have their inertia tensor rows set to zero
btPolyhedralContactClipping: add edge-edge contact point in  findSeparatingAxis (similar to the default GJK case)
This commit is contained in:
erwin.coumans
2012-09-28 07:14:48 +00:00
parent 837e5cb5e0
commit 60bf599246
24 changed files with 385 additions and 153 deletions
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30
src/LinearMath/btGrahamScan2dConvexHull.h
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@@ -21,9 +21,9 @@ subject to the following restrictions:
#include "btVector3.h"
#include "btAlignedObjectArray.h"
struct GrahamVector2 : public btVector3
struct GrahamVector3 : public btVector3
{
GrahamVector2(const btVector3& org, int orgIndex)
GrahamVector3(const btVector3& org, int orgIndex)
:btVector3(org),
m_orgIndex(orgIndex)
{
@@ -39,7 +39,7 @@ struct btAngleCompareFunc {
: m_anchor(anchor)
{
}
bool operator()(const GrahamVector2& a, const GrahamVector2& b) const {
bool operator()(const GrahamVector3& a, const GrahamVector3& b) const {
if (a.m_angle != b.m_angle)
return a.m_angle < b.m_angle;
else
@@ -56,32 +56,38 @@ struct btAngleCompareFunc {
}
};
inline void GrahamScanConvexHull2D(btAlignedObjectArray<GrahamVector2>& originalPoints, btAlignedObjectArray<GrahamVector2>& hull)
inline void GrahamScanConvexHull2D(btAlignedObjectArray<GrahamVector3>& originalPoints, btAlignedObjectArray<GrahamVector3>& hull, const btVector3& normalAxis)
{
btVector3 axis0,axis1;
btPlaneSpace1(normalAxis,axis0,axis1);
if (originalPoints.size()<=1)
{
for (int i=0;i<originalPoints.size();i++)
hull.push_back(originalPoints[0]);
return;
}
//step1 : find anchor point with smallest x/y and move it to first location
//also precompute angles
//step1 : find anchor point with smallest projection on axis0 and move it to first location
for (int i=0;i<originalPoints.size();i++)
{
const btVector3& left = originalPoints[i];
const btVector3& right = originalPoints[0];
if (left.x() < right.x() ||
(!(right.x() < left.x()) && left.y() < right.y()))
btScalar projL = originalPoints[i].dot(axis0);
btScalar projR = originalPoints[0].dot(axis0);
if (projL < projR)
{
originalPoints.swap(0,i);
}
}
for (int i=0;i<originalPoints.size();i++)
//also precompute angles
originalPoints[0].m_angle = -1e30f;
for (int i=1;i<originalPoints.size();i++)
{
btVector3 xvec(1,0,0);
btVector3 xvec = axis0;
btVector3 ar = originalPoints[i]-originalPoints[0];
originalPoints[i].m_angle = btCross(xvec, ar).dot(btVector3(0,0,1)) / ar.length();
originalPoints[i].m_angle = btCross(xvec, ar).dot(normalAxis) / ar.length();
}
//step 2: sort all points, based on 'angle' with this anchor
@@ -99,7 +105,7 @@ inline void GrahamScanConvexHull2D(btAlignedObjectArray<GrahamVector2>& original
while (!isConvex&& hull.size()>1) {
btVector3& a = hull[hull.size()-2];
btVector3& b = hull[hull.size()-1];
isConvex = btCross(a-b,a-originalPoints[i]).dot(btVector3(0,0,1))> 0;
isConvex = btCross(a-b,a-originalPoints[i]).dot(normalAxis)> 0;
if (!isConvex)
hull.pop_back();
else