[Bf-blender-cvs] [f98d388] master: Extended line/face collision near-check, to allow for distance margins.
Lukas Tönne
noreply at git.blender.org
Tue Jan 20 09:49:25 CET 2015
Commit: f98d388fd3b6225101692de994d64955557b3be5
Author: Lukas Tönne
Date: Wed Sep 3 11:17:24 2014 +0200
Branches: master
https://developer.blender.org/rBf98d388fd3b6225101692de994d64955557b3be5
Extended line/face collision near-check, to allow for distance margins.
The original BLI method for line/triangle intersection returns false
in case the line does not actually intersect, but in order to generate
repulsion forces we need to also handle contacts inside the margin.
===================================================================
M source/blender/blenkernel/BKE_collision.h
M source/blender/blenkernel/intern/collision.c
===================================================================
diff --git a/source/blender/blenkernel/BKE_collision.h b/source/blender/blenkernel/BKE_collision.h
index dab5631..c0ee5dc 100644
--- a/source/blender/blenkernel/BKE_collision.h
+++ b/source/blender/blenkernel/BKE_collision.h
@@ -91,9 +91,6 @@ typedef struct CollPair {
int ap1, ap2, ap3, bp1, bp2, bp3;
#endif
int pointsb[4];
-
- /* hair collision */
- float va[3], vb[3]; /* */
}
CollPair;
diff --git a/source/blender/blenkernel/intern/collision.c b/source/blender/blenkernel/intern/collision.c
index e8cad3d..de2d239 100644
--- a/source/blender/blenkernel/intern/collision.c
+++ b/source/blender/blenkernel/intern/collision.c
@@ -1061,6 +1061,7 @@ static bool cloth_points_collision_response_static(ClothModifierData *clmd, Coll
return result;
}
+#if 0
BLI_INLINE void face_normal(float co1[3], float co2[3], float co3[3], float nor[3])
{
float p[3], q[3];
@@ -1069,20 +1070,70 @@ BLI_INLINE void face_normal(float co1[3], float co2[3], float co3[3], float nor[
cross_v3_v3v3(nor, p, q);
normalize_v3(nor);
}
+#endif
+
+BLI_INLINE bool cloth_point_face_collision_params(const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3],
+ float r_nor[3], float *r_lambda, float r_uv[2])
+{
+ float p[3], vec1[3], line[3], edge1[3], edge2[3], q[3];
+ float a, f, u, v;
+
+ sub_v3_v3v3(edge1, v1, v0);
+ sub_v3_v3v3(edge2, v2, v0);
+ sub_v3_v3v3(line, p2, p1);
+
+ cross_v3_v3v3(p, line, edge2);
+ a = dot_v3v3(edge1, p);
+ if (a == 0.0f) return 0;
+ f = 1.0f / a;
+
+ sub_v3_v3v3(vec1, p1, v0);
+
+ u = f * dot_v3v3(vec1, p);
+ if ((u < 0.0f) || (u > 1.0f))
+ return false;
+
+ cross_v3_v3v3(q, vec1, edge1);
+
+ v = f * dot_v3v3(line, q);
+ if ((v < 0.0f) || ((u + v) > 1.0f))
+ return false;
+
+ *r_lambda = f * dot_v3v3(edge2, q);
+ /* don't care about 0..1 lambda range here */
+ /*if ((*r_lambda < 0.0f) || (*r_lambda > 1.0f))
+ * return 0;
+ */
+
+ r_uv[0] = u;
+ r_uv[1] = v;
+
+ cross_v3_v3v3(r_nor, edge1, edge2);
+ normalize_v3(r_nor);
+
+ return true;
+}
static CollPair *cloth_point_collpair(float p1[3], float p2[3], MVert *mverts, int bp1, int bp2, int bp3,
- int index_cloth, int index_coll, CollPair *collpair)
+ int index_cloth, int index_coll, float epsilon, CollPair *collpair)
{
float *co1 = mverts[bp1].co, *co2 = mverts[bp2].co, *co3 = mverts[bp3].co;
- float lambda, uv[2];
- float fnor[3], vec[3];
+ float lambda, uv[2], distance1, distance2;
+ float facenor[3], v1p1[3], v1p2[3];
float w[3];
+
+// if (!isect_line_tri_v3(p1, p2, co1, co2, co3, &lambda, uv))
+// return collpair;
- if (!isect_line_tri_v3(p1, p2, co1, co2, co3, &lambda, uv))
+ if (!cloth_point_face_collision_params(p1, p2, co1, co2, co3, facenor, &lambda, uv))
return collpair;
- face_normal(co1, co2, co3, fnor);
- sub_v3_v3v3(vec, p2, p1);
+ sub_v3_v3v3(v1p1, p1, co1);
+ distance1 = dot_v3v3(v1p1, facenor);
+ sub_v3_v3v3(v1p2, p2, co1);
+ distance2 = dot_v3v3(v1p2, facenor);
+ if (distance2 > epsilon || (distance1 < 0.0f && distance2 < 0.0f))
+ return collpair;
collpair->face1 = index_cloth; /* XXX actually not a face, but equivalent index for point */
collpair->face2 = index_coll;
@@ -1096,18 +1147,15 @@ static CollPair *cloth_point_collpair(float p1[3], float p2[3], MVert *mverts, i
* the current updated position that needs to be corrected
*/
copy_v3_v3(collpair->pa, p2);
- collpair->distance = dot_v3v3(fnor, vec) * lambda;
+ collpair->distance = distance2;
+ mul_v3_v3fl(collpair->vector, facenor, distance2);
w[0] = 1.0f - uv[0] - uv[1];
w[1] = uv[0];
w[2] = uv[1];
interp_v3_v3v3v3(collpair->pb, co1, co2, co3, w);
- /* note: face normal smoothing is ignored here,
- * it would probably not work with collision response
- */
- copy_v3_v3(collpair->normal, fnor);
- copy_v3_v3(collpair->vector, vec);
+ copy_v3_v3(collpair->normal, facenor);
collpair->time = lambda;
collpair->flag = 0;
@@ -1117,7 +1165,7 @@ static CollPair *cloth_point_collpair(float p1[3], float p2[3], MVert *mverts, i
//Determines collisions on overlap, collisions are written to collpair[i] and collision+number_collision_found is returned
static CollPair* cloth_point_collision(ModifierData *md1, ModifierData *md2,
- BVHTreeOverlap *overlap, CollPair *collpair, float UNUSED(dt))
+ BVHTreeOverlap *overlap, float epsilon, CollPair *collpair, float UNUSED(dt))
{
ClothModifierData *clmd = (ClothModifierData *)md1;
CollisionModifierData *collmd = (CollisionModifierData *) md2;
@@ -1129,16 +1177,16 @@ static CollPair* cloth_point_collision(ModifierData *md1, ModifierData *md2,
vert = &clmd->clothObject->verts[overlap->indexA];
face = &collmd->mfaces[overlap->indexB];
- collpair = cloth_point_collpair(vert->x, vert->tx, mverts, face->v1, face->v2, face->v3, overlap->indexA, overlap->indexB, collpair);
+ collpair = cloth_point_collpair(vert->x, vert->tx, mverts, face->v1, face->v2, face->v3, overlap->indexA, overlap->indexB, epsilon, collpair);
if (face->v4)
- collpair = cloth_point_collpair(vert->x, vert->tx, mverts, face->v3, face->v4, face->v1, overlap->indexA, overlap->indexB, collpair);
+ collpair = cloth_point_collpair(vert->x, vert->tx, mverts, face->v3, face->v4, face->v1, overlap->indexA, overlap->indexB, epsilon, collpair);
return collpair;
}
static void cloth_points_objcollisions_nearcheck(ClothModifierData * clmd, CollisionModifierData *collmd,
CollPair **collisions, CollPair **collisions_index,
- int numresult, BVHTreeOverlap *overlap, double dt)
+ int numresult, BVHTreeOverlap *overlap, float epsilon, double dt)
{
int i;
@@ -1148,7 +1196,7 @@ static void cloth_points_objcollisions_nearcheck(ClothModifierData * clmd, Colli
for ( i = 0; i < numresult; i++ ) {
*collisions_index = cloth_point_collision((ModifierData *)clmd, (ModifierData *)collmd,
- overlap+i, *collisions_index, dt);
+ overlap+i, epsilon, *collisions_index, dt);
}
}
@@ -1246,18 +1294,20 @@ int cloth_points_objcollision(Object *ob, ClothModifierData *clmd, float step, f
CollisionModifierData *collmd = (CollisionModifierData *)modifiers_findByType(collob, eModifierType_Collision);
BVHTreeOverlap *overlap = NULL;
unsigned int result = 0;
+ float epsilon;
if (!collmd->bvhtree)
continue;
/* search for overlapping collision pairs */
overlap = BLI_bvhtree_overlap ( cloth_bvh, collmd->bvhtree, &result );
+ epsilon = BLI_bvhtree_getepsilon(collmd->bvhtree);
// go to next object if no overlap is there
if (result && overlap) {
/* check if collisions really happen (costly near check) */
cloth_points_objcollisions_nearcheck(clmd, collmd, &collisions[i], &collisions_index[i],
- result, overlap, round_dt);
+ result, overlap, epsilon, round_dt);
// resolve nearby collisions
ret += cloth_points_objcollisions_resolve(clmd, collmd, collob->pd, collisions[i], collisions_index[i], round_dt);
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