[Bf-blender-cvs] [5f6d9e3] strand_gpu: Implementation of Volume Sampling on meshes.

Lukas Tönne noreply at git.blender.org
Tue Jul 5 09:56:44 CEST 2016


Commit: 5f6d9e301efc5f9627941c71ba0f464901e71a4e
Author: Lukas Tönne
Date:   Fri Aug 21 15:13:17 2015 +0200
Branches: strand_gpu
https://developer.blender.org/rB5f6d9e301efc5f9627941c71ba0f464901e71a4e

Implementation of Volume Sampling on meshes.

Based on the ray casting technique described here: http://www.joesfer.com/?p=84

Volume samples currently are not bound to mesh deformation in any way, they are
simple object-space locations. Potentially a harmonic weight approach as in
mesh cages could be used.

===================================================================

M	source/blender/blenkernel/BKE_mesh_sample.h
M	source/blender/blenkernel/intern/mesh_sample.c
M	source/blender/makesdna/DNA_meshdata_types.h
M	source/blender/makesrna/intern/CMakeLists.txt
M	source/blender/makesrna/intern/makesrna.c
M	source/blender/makesrna/intern/rna_internal.h
D	source/blender/makesrna/intern/rna_mesh_sample.c

===================================================================

diff --git a/source/blender/blenkernel/BKE_mesh_sample.h b/source/blender/blenkernel/BKE_mesh_sample.h
index 9e34441..3b2e1e1 100644
--- a/source/blender/blenkernel/BKE_mesh_sample.h
+++ b/source/blender/blenkernel/BKE_mesh_sample.h
@@ -28,32 +28,37 @@
 struct DerivedMesh;
 struct Key;
 struct KeyBlock;
+struct MFace;
+struct MVert;
 
-struct MSurfaceSample;
+struct MeshSample;
+struct MeshSampleGenerator;
+
+typedef struct MeshSampleGenerator MeshSampleGenerator;
+typedef float (*MeshSampleVertexWeightFp)(struct DerivedMesh *dm, struct MVert *vert, unsigned int index, void *userdata);
+typedef bool (*MeshSampleRayFp)(void *userdata, float ray_start[3], float ray_end[3]);
 
 /* ==== Evaluate ==== */
 
-bool BKE_mesh_sample_eval(struct DerivedMesh *dm, const struct MSurfaceSample *sample, float loc[3], float nor[3]);
-bool BKE_mesh_sample_shapekey(struct Key *key, struct KeyBlock *kb, const struct MSurfaceSample *sample, float loc[3]);
+bool BKE_mesh_sample_is_volume_sample(const struct MeshSample *sample);
+
+bool BKE_mesh_sample_eval(struct DerivedMesh *dm, const struct MeshSample *sample, float loc[3], float nor[3], float tang[3]);
+bool BKE_mesh_sample_shapekey(struct Key *key, struct KeyBlock *kb, const struct MeshSample *sample, float loc[3]);
 
 
 /* ==== Sampling ==== */
 
-/* Storage descriptor to allow generic data storage by arbitrary algorithms */
-typedef struct MSurfaceSampleStorage {
-	bool (*store_sample)(void *data, int capacity, int index, const struct MSurfaceSample *sample);
-	void *data;
-	int capacity;
-	int free_data;
-} MSurfaceSampleStorage;
+/* face_weights is optional */
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_random(struct DerivedMesh *dm, unsigned int seed);
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_random_ex(struct DerivedMesh *dm, unsigned int seed,
+                                                                      MeshSampleVertexWeightFp vertex_weight_cb, void *userdata, bool use_facearea);
+
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_raycast(struct DerivedMesh *dm, MeshSampleRayFp ray_cb, void *userdata);
 
-void BKE_mesh_sample_storage_single(struct MSurfaceSampleStorage *storage, struct MSurfaceSample *sample);
-void BKE_mesh_sample_storage_array(struct MSurfaceSampleStorage *storage, struct MSurfaceSample *samples, int capacity);
-void BKE_mesh_sample_storage_release(struct MSurfaceSampleStorage *storage);
+struct MeshSampleGenerator *BKE_mesh_sample_gen_volume_random_bbray(struct DerivedMesh *dm, unsigned int seed, float density);
 
-int BKE_mesh_sample_generate_random(struct MSurfaceSampleStorage *dst, struct DerivedMesh *dm, unsigned int seed, int totsample);
+void BKE_mesh_sample_free_generator(struct MeshSampleGenerator *gen);
 
-typedef bool (*MeshSampleRayCallback)(void *userdata, float ray_start[3], float ray_end[3]);
-int BKE_mesh_sample_generate_raycast(struct MSurfaceSampleStorage *dst, struct DerivedMesh *dm, MeshSampleRayCallback ray_cb, void *userdata, int totsample);
+bool BKE_mesh_sample_generate(struct MeshSampleGenerator *gen, struct MeshSample *sample);
 
 #endif  /* __BKE_MESH_SAMPLE_H__ */
diff --git a/source/blender/blenkernel/intern/mesh_sample.c b/source/blender/blenkernel/intern/mesh_sample.c
index ae49668..537b565 100644
--- a/source/blender/blenkernel/intern/mesh_sample.c
+++ b/source/blender/blenkernel/intern/mesh_sample.c
@@ -43,45 +43,80 @@
 
 /* ==== Evaluate ==== */
 
-bool BKE_mesh_sample_eval(DerivedMesh *dm, const MSurfaceSample *sample, float loc[3], float nor[3])
+bool BKE_mesh_sample_is_volume_sample(const MeshSample *sample)
+{
+	return sample->orig_verts[0] == 0 && sample->orig_verts[1] == 0;
+}
+
+bool BKE_mesh_sample_eval(DerivedMesh *dm, const MeshSample *sample, float loc[3], float nor[3], float tang[3])
 {
 	MVert *mverts = dm->getVertArray(dm);
 	unsigned int totverts = (unsigned int)dm->getNumVerts(dm);
 	MVert *v1, *v2, *v3;
-	float vnor[3];
 	
 	zero_v3(loc);
 	zero_v3(nor);
+	zero_v3(tang);
 	
-	if (sample->orig_verts[0] >= totverts ||
-	    sample->orig_verts[1] >= totverts ||
-	    sample->orig_verts[2] >= totverts)
-		return false;
-	
-	v1 = &mverts[sample->orig_verts[0]];
-	v2 = &mverts[sample->orig_verts[1]];
-	v3 = &mverts[sample->orig_verts[2]];
-	
-	madd_v3_v3fl(loc, v1->co, sample->orig_weights[0]);
-	madd_v3_v3fl(loc, v2->co, sample->orig_weights[1]);
-	madd_v3_v3fl(loc, v3->co, sample->orig_weights[2]);
-	
-	normal_short_to_float_v3(vnor, v1->no);
-	madd_v3_v3fl(nor, vnor, sample->orig_weights[0]);
-	normal_short_to_float_v3(vnor, v2->no);
-	madd_v3_v3fl(nor, vnor, sample->orig_weights[1]);
-	normal_short_to_float_v3(vnor, v3->no);
-	madd_v3_v3fl(nor, vnor, sample->orig_weights[2]);
-	
-	normalize_v3(nor);
+	if (BKE_mesh_sample_is_volume_sample(sample)) {
+		/* VOLUME SAMPLE */
+		copy_v3_v3(loc, sample->orig_weights);
+	}
+	else {
+		/* SURFACE SAMPLE */
+		if (sample->orig_verts[0] >= totverts ||
+		    sample->orig_verts[1] >= totverts ||
+		    sample->orig_verts[2] >= totverts)
+			return false;
+		
+		v1 = &mverts[sample->orig_verts[0]];
+		v2 = &mverts[sample->orig_verts[1]];
+		v3 = &mverts[sample->orig_verts[2]];
+		
+		{ /* location */
+			madd_v3_v3fl(loc, v1->co, sample->orig_weights[0]);
+			madd_v3_v3fl(loc, v2->co, sample->orig_weights[1]);
+			madd_v3_v3fl(loc, v3->co, sample->orig_weights[2]);
+		}
+		
+		{ /* normal */
+			float vnor[3];
+			
+			normal_short_to_float_v3(vnor, v1->no);
+			madd_v3_v3fl(nor, vnor, sample->orig_weights[0]);
+			normal_short_to_float_v3(vnor, v2->no);
+			madd_v3_v3fl(nor, vnor, sample->orig_weights[1]);
+			normal_short_to_float_v3(vnor, v3->no);
+			madd_v3_v3fl(nor, vnor, sample->orig_weights[2]);
+			
+			normalize_v3(nor);
+		}
+		
+		{ /* tangent */
+			float edge[3];
+			
+			/* XXX simply using the v1-v2 edge as a tangent vector for now ...
+		 * Eventually mikktspace generated tangents (CD_TANGENT tessface layer)
+		 * should be used for consistency, but requires well-defined tessface
+		 * indices for the mesh surface samples.
+		 */
+			
+			sub_v3_v3v3(edge, v2->co, v1->co);
+			/* make edge orthogonal to nor */
+			madd_v3_v3fl(edge, nor, -dot_v3v3(edge, nor));
+			normalize_v3_v3(tang, edge);
+		}
+	}
 	
 	return true;
 }
 
-bool BKE_mesh_sample_shapekey(Key *key, KeyBlock *kb, const MSurfaceSample *sample, float loc[3])
+bool BKE_mesh_sample_shapekey(Key *key, KeyBlock *kb, const MeshSample *sample, float loc[3])
 {
 	float *v1, *v2, *v3;
-	
+
+	(void)key;  /* Unused in release builds. */
+
 	BLI_assert(key->elemsize == 3 * sizeof(float));
 	BLI_assert(sample->orig_verts[0] < (unsigned int)kb->totelem);
 	BLI_assert(sample->orig_verts[1] < (unsigned int)kb->totelem);
@@ -103,7 +138,7 @@ bool BKE_mesh_sample_shapekey(Key *key, KeyBlock *kb, const MSurfaceSample *samp
 
 /* ==== Sampling Utilities ==== */
 
-BLI_INLINE void mesh_sample_weights_from_loc(MSurfaceSample *sample, DerivedMesh *dm, int face_index, const float loc[3])
+BLI_INLINE void mesh_sample_weights_from_loc(MeshSample *sample, DerivedMesh *dm, int face_index, const float loc[3])
 {
 	MFace *face = &dm->getTessFaceArray(dm)[face_index];
 	unsigned int index[4] = { face->v1, face->v2, face->v3, face->v4 };
@@ -128,108 +163,278 @@ BLI_INLINE void mesh_sample_weights_from_loc(MSurfaceSample *sample, DerivedMesh
 
 /* ==== Sampling ==== */
 
-static bool mesh_sample_store_array_sample(void *vdata, int capacity, int index, const MSurfaceSample *sample)
+typedef void (*GeneratorFreeFp)(struct MeshSampleGenerator *gen);
+typedef bool (*GeneratorMakeSampleFp)(struct MeshSampleGenerator *gen, struct MeshSample *sample);
+
+typedef struct MeshSampleGenerator
 {
-	MSurfaceSample *data = vdata;
-	if (index >= capacity)
-		return false;
-	
-	data[index] = *sample;
-	return true;
-}
+	GeneratorFreeFp free;
+	GeneratorMakeSampleFp make_sample;
+} MeshSampleGenerator;
 
-void BKE_mesh_sample_storage_single(MSurfaceSampleStorage *storage, MSurfaceSample *sample)
+static void sample_generator_init(MeshSampleGenerator *gen, GeneratorFreeFp free, GeneratorMakeSampleFp make_sample)
 {
-	/* handled as just a special array case with capacity = 1 */
-	storage->store_sample = mesh_sample_store_array_sample;
-	storage->capacity = 1;
-	storage->data = sample;
-	storage->free_data = false;
+	gen->free = free;
+	gen->make_sample = make_sample;
 }
 
-void BKE_mesh_sample_storage_array(MSurfaceSampleStorage *storage, MSurfaceSample *samples, int capacity)
+/* ------------------------------------------------------------------------- */
+
+//#define USE_DEBUG_COUNT
+
+typedef struct MSurfaceSampleGenerator_Random {
+	MeshSampleGenerator base;
+	
+	DerivedMesh *dm;
+	RNG *rng;
+	float *face_weights;
+	float *vertex_weights;
+	
+#ifdef USE_DEBUG_COUNT
+	int *debug_count;
+#endif
+} MSurfaceSampleGenerator_Random;
+
+static void generator_random_free(MSurfaceSampleGenerator_Random *gen)
 {
-	storage->store_sample = mesh_sample_store_array_sample;
-	storage->capacity = capacity;
-	storage->data = samples;
-	storage->free_data = false;
+#ifdef USE_DEBUG_COUNT
+	if (gen->debug_count) {
+		if (gen->face_weights) {
+			int num = gen->dm->getNumTessFaces(gen->dm);
+			int i;
+			int totsamples = 0;
+			
+			printf("Surface Sampling (n=%d):\n", num);
+			for (i = 0; i < num; ++i)
+				totsamples += gen->debug_count[i];
+			
+			for (i = 0; i < num; ++i) {
+				float weight = i > 0 ? gen->face_weights[i] - gen->face_weights[i-1] : gen->face_weights[i];
+				int samples = gen->debug_count[i];
+				printf("  %d: W = %f, N = %d/%d = %f\n", i, weight, samples, totsamples, (float)samples / (float)totsamples);
+			}
+		}
+		MEM_freeN(gen->debug_count);
+	}
+#endif
+	if (gen->face_weights)
+		MEM_freeN(gen->face_weights);
+	if (gen->vertex_weights)
+		MEM_freeN(gen->vertex_weights);
+	if (gen->rng)
+		BLI_rng_free(gen->rng);
+	MEM_freeN(gen);
 }
 
-void BKE_mesh_sample_storage_release(MSurfaceSampleStorage *storage)
+/* Find the index in "sum" array before "value" is crossed. */
+BLI_INLINE int weight_array_binary_search(const float *sum, int size, float value)
 {
-	if (storage->free_data)
-		MEM_freeN(storage->data);
+	int mid, low = 0, high = size - 1;
+	
+	if (value <= 0.0f)
+		return 0;
+	
+	while (low < high) {
+		mid =

@@ Diff output truncated at 10240 characters. @@




More information about the Bf-blender-cvs mailing list