public CHull canMerge(CHull a, CHull b)
{
if (!a.overlap(b)) // if their AABB's (with a little slop) don't overlap, then return.
{
return(null);
}
CHull ret = null;
// ok..we are going to combine both meshes into a single mesh
// and then we are going to compute the concavity...
VertexPool vc = new VertexPool();
List <int> indices = new List <int>();
getMesh(a.mResult, vc, indices);
getMesh(b.mResult, vc, indices);
// 20131224 not used int vcount = vc.GetSize();
List <float3> vertices = vc.GetVertices();
int tcount = indices.Count / 3;
//don't do anything if hull is empty
if (tcount == 0)
{
vc.Clear();
return(null);
}
HullResult hresult = new HullResult();
HullDesc desc = new HullDesc();
desc.SetHullFlag(HullFlag.QF_TRIANGLES);
desc.Vertices = vertices;
HullError hret = HullUtils.CreateConvexHull(desc, ref hresult);
if (hret == HullError.QE_OK)
{
float combineVolume = Concavity.computeMeshVolume(hresult.OutputVertices, hresult.Indices);
float sumVolume = a.mVolume + b.mVolume;
float percent = (sumVolume * 100) / combineVolume;
if (percent >= (100.0f - MERGE_PERCENT))
{
ConvexResult cr = new ConvexResult(hresult.OutputVertices, hresult.Indices);
ret = new CHull(cr);
}
}
vc.Clear();
return(ret);
}
// compute's how 'concave' this object is and returns the total volume of the
// convex hull as well as the volume of the 'concavity' which was found.
public static float computeConcavity(List <float3> vertices, List <int> indices, ref float4 plane, ref float volume)
{
float cret = 0f;
volume = 1f;
HullResult result = new HullResult();
HullDesc desc = new HullDesc();
desc.MaxFaces = 256;
desc.MaxVertices = 256;
desc.SetHullFlag(HullFlag.QF_TRIANGLES);
desc.Vertices = vertices;
HullError ret = HullUtils.CreateConvexHull(desc, ref result);
if (ret == HullError.QE_OK)
{
volume = computeMeshVolume2(result.OutputVertices, result.Indices);
// ok..now..for each triangle on the original mesh..
// we extrude the points to the nearest point on the hull.
List <CTri> tris = new List <CTri>();
for (int i = 0; i < result.Indices.Count / 3; i++)
{
int i1 = result.Indices[i * 3 + 0];
int i2 = result.Indices[i * 3 + 1];
int i3 = result.Indices[i * 3 + 2];
float3 p1 = result.OutputVertices[i1];
float3 p2 = result.OutputVertices[i2];
float3 p3 = result.OutputVertices[i3];
CTri t = new CTri(p1, p2, p3, i1, i2, i3);
tris.Add(t);
}
// we have not pre-computed the plane equation for each triangle in the convex hull..
float totalVolume = 0;
List <CTri> ftris = new List <CTri>(); // 'feature' triangles.
List <CTri> input_mesh = new List <CTri>();
for (int i = 0; i < indices.Count / 3; i++)
{
int i1 = indices[i * 3 + 0];
int i2 = indices[i * 3 + 1];
int i3 = indices[i * 3 + 2];
float3 p1 = vertices[i1];
float3 p2 = vertices[i2];
float3 p3 = vertices[i3];
CTri t = new CTri(p1, p2, p3, i1, i2, i3);
input_mesh.Add(t);
}
for (int i = 0; i < indices.Count / 3; i++)
{
int i1 = indices[i * 3 + 0];
int i2 = indices[i * 3 + 1];
int i3 = indices[i * 3 + 2];
float3 p1 = vertices[i1];
float3 p2 = vertices[i2];
float3 p3 = vertices[i3];
CTri t = new CTri(p1, p2, p3, i1, i2, i3);
featureMatch(t, tris, input_mesh);
if (t.mConcavity > 0.05f)
{
float v = t.getVolume();
totalVolume += v;
ftris.Add(t);
}
}
SplitPlane.computeSplitPlane(vertices, indices, ref plane);
cret = totalVolume;
}
return(cret);
}
public int process(DecompDesc desc)
{
int ret = 0;
MAXDEPTH = (int)desc.mDepth;
CONCAVE_PERCENT = desc.mCpercent;
MERGE_PERCENT = desc.mPpercent;
ConvexDecomposition.calcConvexDecomposition(desc.mVertices, desc.mIndices, ConvexDecompResult, 0f, 0, MAXDEPTH, CONCAVE_PERCENT, MERGE_PERCENT);
while (combineHulls()) // keep combinging hulls until I can't combine any more...
{
;
}
int i;
for (i = 0; i < mChulls.Count; i++)
{
CHull cr = mChulls[i];
// before we hand it back to the application, we need to regenerate the hull based on the
// limits given by the user.
ConvexResult c = cr.mResult; // the high resolution hull...
HullResult result = new HullResult();
HullDesc hdesc = new HullDesc();
hdesc.SetHullFlag(HullFlag.QF_TRIANGLES);
hdesc.Vertices = c.HullVertices;
hdesc.MaxVertices = desc.mMaxVertices; // maximum number of vertices allowed in the output
if (desc.mSkinWidth != 0f)
{
hdesc.SkinWidth = desc.mSkinWidth;
hdesc.SetHullFlag(HullFlag.QF_SKIN_WIDTH); // do skin width computation.
}
HullError ret2 = HullUtils.CreateConvexHull(hdesc, ref result);
if (ret2 == HullError.QE_OK)
{
ConvexResult r = new ConvexResult(result.OutputVertices, result.Indices);
r.mHullVolume = Concavity.computeMeshVolume(result.OutputVertices, result.Indices); // the volume of the hull.
// compute the best fit OBB
//computeBestFitOBB(result.mNumOutputVertices, result.mOutputVertices, sizeof(float) * 3, r.mOBBSides, r.mOBBTransform);
//r.mOBBVolume = r.mOBBSides[0] * r.mOBBSides[1] * r.mOBBSides[2]; // compute the OBB volume.
//fm_getTranslation(r.mOBBTransform, r.mOBBCenter); // get the translation component of the 4x4 matrix.
//fm_matrixToQuat(r.mOBBTransform, r.mOBBOrientation); // extract the orientation as a quaternion.
//r.mSphereRadius = computeBoundingSphere(result.mNumOutputVertices, result.mOutputVertices, r.mSphereCenter);
//r.mSphereVolume = fm_sphereVolume(r.mSphereRadius);
mCallback(r);
}
result = null;
cr.Dispose();
}
ret = mChulls.Count;
mChulls.Clear();
return(ret);
}
public static void calcConvexDecomposition(List <float3> vertices, List <int> indices, ConvexDecompositionCallback callback, float masterVolume, int depth,
int maxDepth, float concavePercent, float mergePercent)
{
float4 plane = new float4();
bool split = false;
if (depth < maxDepth)
{
float volume = 0f;
float c = Concavity.computeConcavity(vertices, indices, ref plane, ref volume);
if (depth == 0)
{
masterVolume = volume;
}
float percent = (c * 100.0f) / masterVolume;
if (percent > concavePercent) // if great than 5% of the total volume is concave, go ahead and keep splitting.
{
split = true;
}
}
if (depth >= maxDepth || !split)
{
HullResult result = new HullResult();
HullDesc desc = new HullDesc();
desc.SetHullFlag(HullFlag.QF_TRIANGLES);
desc.Vertices = vertices;
HullError ret = HullUtils.CreateConvexHull(desc, ref result);
if (ret == HullError.QE_OK)
{
ConvexResult r = new ConvexResult(result.OutputVertices, result.Indices);
callback(r);
}
return;
}
List <int> ifront = new List <int>();
List <int> iback = new List <int>();
VertexPool vfront = new VertexPool();
VertexPool vback = new VertexPool();
// ok..now we are going to 'split' all of the input triangles against this plane!
for (int i = 0; i < indices.Count / 3; i++)
{
int i1 = indices[i * 3 + 0];
int i2 = indices[i * 3 + 1];
int i3 = indices[i * 3 + 2];
FaceTri t = new FaceTri(vertices, i1, i2, i3);
float3[] front = new float3[4];
float3[] back = new float3[4];
int fcount = 0;
int bcount = 0;
PlaneTriResult result = PlaneTri.planeTriIntersection(plane, t, 0.00001f, ref front, out fcount, ref back, out bcount);
if (fcount > 4 || bcount > 4)
{
result = PlaneTri.planeTriIntersection(plane, t, 0.00001f, ref front, out fcount, ref back, out bcount);
}
switch (result)
{
case PlaneTriResult.PTR_FRONT:
Debug.Assert(fcount == 3);
addTri(vfront, ifront, front[0], front[1], front[2]);
break;
case PlaneTriResult.PTR_BACK:
Debug.Assert(bcount == 3);
addTri(vback, iback, back[0], back[1], back[2]);
break;
case PlaneTriResult.PTR_SPLIT:
Debug.Assert(fcount >= 3 && fcount <= 4);
Debug.Assert(bcount >= 3 && bcount <= 4);
addTri(vfront, ifront, front[0], front[1], front[2]);
addTri(vback, iback, back[0], back[1], back[2]);
if (fcount == 4)
{
addTri(vfront, ifront, front[0], front[2], front[3]);
}
if (bcount == 4)
{
addTri(vback, iback, back[0], back[2], back[3]);
}
break;
}
}
// ok... here we recursively call
if (ifront.Count > 0)
{
// 20131224 not used int vcount = vfront.GetSize();
List <float3> vertices2 = vfront.GetVertices();
for (int i = 0; i < vertices2.Count; i++)
{
vertices2[i] = new float3(vertices2[i]);
}
// 20131224 not used int tcount = ifront.Count / 3;
calcConvexDecomposition(vertices2, ifront, callback, masterVolume, depth + 1, maxDepth, concavePercent, mergePercent);
}
ifront.Clear();
vfront.Clear();
if (iback.Count > 0)
{
// 20131224 not used int vcount = vback.GetSize();
List <float3> vertices2 = vback.GetVertices();
// 20131224 not used int tcount = iback.Count / 3;
calcConvexDecomposition(vertices2, iback, callback, masterVolume, depth + 1, maxDepth, concavePercent, mergePercent);
}
iback.Clear();
vback.Clear();
}
public int process(DecompDesc desc)
{
int ret = 0;
MAXDEPTH = (int)desc.mDepth;
CONCAVE_PERCENT = desc.mCpercent;
MERGE_PERCENT = desc.mPpercent;
ConvexDecomposition.calcConvexDecomposition(desc.mVertices, desc.mIndices, ConvexDecompResult, 0f, 0, MAXDEPTH, CONCAVE_PERCENT, MERGE_PERCENT);
while (combineHulls()) // keep combinging hulls until I can't combine any more...
{
;
}
int i;
for (i = 0; i < mChulls.Count; i++)
{
CHull cr = mChulls[i];
// before we hand it back to the application, we need to regenerate the hull based on the
// limits given by the user.
ConvexResult c = cr.mResult; // the high resolution hull...
HullResult result = new HullResult();
HullDesc hdesc = new HullDesc();
hdesc.SetHullFlag(HullFlag.QF_TRIANGLES);
hdesc.Vertices = c.HullVertices;
hdesc.MaxVertices = desc.mMaxVertices; // maximum number of vertices allowed in the output
if (desc.mSkinWidth != 0f)
{
hdesc.SkinWidth = desc.mSkinWidth;
hdesc.SetHullFlag(HullFlag.QF_SKIN_WIDTH); // do skin width computation.
}
HullError ret2 = HullUtils.CreateConvexHull(hdesc, ref result);
if (ret2 == HullError.QE_OK)
{
ConvexResult r = new ConvexResult(result.OutputVertices, result.Indices);
r.mHullVolume = Concavity.computeMeshVolume(result.OutputVertices, result.Indices); // the volume of the hull.
mCallback(r);
}
result = null;
cr.Dispose();
}
ret = mChulls.Count;
mChulls.Clear();
return(ret);
}