Use a fixed, uniform cell size for hair continuum grids.

This is a bit more awkward for artists to use, but necessary for
a stable solution of the hair continuum calculation. The grid size is
defined by the user, the extent of the grid is then calculated based on
the hair geometry. A hard upper limit prevents bad memory allocation
in case too small values are entered.

Conflicts:
	source/blender/physics/intern/BPH_mass_spring.cpp

1 files changed, 9 insertions, 14 deletions

diff --git a/source/blender/physics/intern/BPH_mass_spring.cpp b/source/blender/physics/intern/BPH_mass_spring.cpp
index 15693965fe0..45032b1f233 100644
--- a/source/blender/physics/intern/BPH_mass_spring.cpp
+++ b/source/blender/physics/intern/BPH_mass_spring.cpp
@@ -584,7 +584,7 @@ static void cloth_calc_volume_force(ClothModifierData *clmd)
 #endif

 

 /* returns active vertexes' motion state, or original location the vertex is disabled */

-BLI_INLINE bool cloth_get_grid_location(Implicit_Data *data, const float cell_scale[3], const float cell_offset[3],

+BLI_INLINE bool cloth_get_grid_location(Implicit_Data *data, float cell_scale, const float cell_offset[3],

                                         ClothVertex *vert, int index, float x[3], float v[3])

 {

 	bool is_motion_state;

@@ -592,7 +592,7 @@ BLI_INLINE bool cloth_get_grid_location(Implicit_Data *data, const float cell_sc
 	BPH_mass_spring_get_new_velocity(data, index, v);

 	is_motion_state = true;

 	

-	mul_v3_v3(x, cell_scale);

+	mul_v3_fl(x, cell_scale);

 	add_v3_v3(x, cell_offset);

 	

 	return is_motion_state;

@@ -618,7 +618,7 @@ BLI_INLINE LinkNode *hair_spring_next(LinkNode *spring_link)
  *   (3,4), (2,3), (1,2)

  * This is currently the only way to figure out hair geometry inside this code ...

  */

-static LinkNode *cloth_continuum_add_hair_segments(HairGrid *grid, const float cell_scale[3], const float cell_offset[3], Cloth *cloth, LinkNode *spring_link)

+static LinkNode *cloth_continuum_add_hair_segments(HairGrid *grid, const float cell_scale, const float cell_offset[3], Cloth *cloth, LinkNode *spring_link)

 {

 	Implicit_Data *data = cloth->implicit;

 	LinkNode *next_spring_link = NULL; /* return value */

@@ -723,16 +723,14 @@ static void cloth_continuum_fill_grid(HairGrid *grid, Cloth *cloth)
 	}

 #else

 	LinkNode *link;

-	float cellsize[3], gmin[3], cell_scale[3], cell_offset[3];

+	float cellsize, gmin[3], cell_scale, cell_offset[3];

 	

 	/* scale and offset for transforming vertex locations into grid space

 	 * (cell size is 0..1, gmin becomes origin)

 	 */

-	BPH_hair_volume_grid_geometry(grid, cellsize, NULL, gmin, NULL);

-	cell_scale[0] = cellsize[0] > 0.0f ? 1.0f / cellsize[0] : 0.0f;

-	cell_scale[1] = cellsize[1] > 0.0f ? 1.0f / cellsize[1] : 0.0f;

-	cell_scale[2] = cellsize[2] > 0.0f ? 1.0f / cellsize[2] : 0.0f;

-	mul_v3_v3v3(cell_offset, gmin, cell_scale);

+	BPH_hair_volume_grid_geometry(grid, &cellsize, NULL, gmin, NULL);

+	cell_scale = cellsize > 0.0f ? 1.0f / cellsize : 0.0f;

+	mul_v3_v3fl(cell_offset, gmin, cell_scale);

 	negate_v3(cell_offset);

 	

 	link = cloth->springs;

@@ -760,7 +758,6 @@ static void cloth_continuum_step(ClothModifierData *clmd)
 	float pressfac = parms->pressure;

 	float minpress = parms->pressure_threshold;

 	float gmin[3], gmax[3];

-	float cellsize[3];

 	int i;

 	

 	/* clear grid info */

@@ -772,11 +769,9 @@ static void cloth_continuum_step(ClothModifierData *clmd)
 	

 	/* gather velocities & density */

 	if (smoothfac > 0.0f || pressfac > 0.0f) {

-		HairGrid *grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_res, gmin, gmax);

+		HairGrid *grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_cell_size, gmin, gmax);

 		BPH_hair_volume_set_debug_data(grid, clmd->debug_data);

 		

-		BPH_hair_volume_grid_geometry(grid, cellsize, NULL, NULL, NULL);

-		

 		cloth_continuum_fill_grid(grid, cloth);

 		

 		for (i = 0, vert = cloth->verts; i < numverts; i++, vert++) {

@@ -1010,7 +1005,7 @@ bool BPH_cloth_solver_get_texture_data(Object *UNUSED(ob), ClothModifierData *cl
 	

 	hair_get_boundbox(clmd, gmin, gmax);

 	

-	grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_res, gmin, gmax);

+	grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_cell_size, gmin, gmax);

 	cloth_continuum_fill_grid(grid, cloth);

 	

 	BPH_hair_volume_get_texture_data(grid, vd);