Adding a new SPH solver that is more physically accurate. See patch #29681

    http://projects.blender.org/tracker/index.php?func=detail&aid=29681&group_id=9&atid=127

The solver was mostly implemented by John Mansour at VPAC, with help from me and with funding from the AutoCRC. The SPH formulation is due to Gingold and Monaghan, and the smoothing kernel is due to Wendland.

This solver does not replace the old one; it is available as an option. Note that the new solver uses different units than the old one. The patch page has a couple of attachments that can be used to test the new solver, particularly sphclassical_dam_s0.01_grav.blend (ignore the earlier tests). The simulation in that file compares well with a physical experimental dam break; details in a paper by Changhong Hu and Makoto Sueyoshi, also referred to on that page.

1 files changed, 18 insertions, 5 deletions

diff --git a/source/blender/makesrna/intern/rna_particle.c b/source/blender/makesrna/intern/rna_particle.c
index 96b6197cf69..93f940b1aa3 100644
--- a/source/blender/makesrna/intern/rna_particle.c
+++ b/source/blender/makesrna/intern/rna_particle.c
@@ -1112,12 +1112,25 @@ static void rna_def_fluid_settings(BlenderRNA *brna)
 {
 	StructRNA *srna;
 	PropertyRNA *prop;
-	
+
+	static EnumPropertyItem sph_solver_items[] = {
+		{SPH_SOLVER_DDR, "DDR", 0, "Double-Density", "An artistic solver with strong surface tension effects (original)"},
+		{SPH_SOLVER_CLASSICAL, "CLASSICAL", 0, "Classical", "A more physically-accurate solver"},
+		{0, NULL, 0, NULL, NULL}
+	};
+
 	srna = RNA_def_struct(brna, "SPHFluidSettings", NULL);
 	RNA_def_struct_path_func(srna, "rna_SPHFluidSettings_path");
 	RNA_def_struct_ui_text(srna, "SPH Fluid Settings", "Settings for particle fluids physics");
-	
+
 	/* Fluid settings */
+	prop = RNA_def_property(srna, "solver", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "solver");
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+	RNA_def_property_enum_items(prop, sph_solver_items);
+	RNA_def_property_ui_text(prop, "SPH Solver", "The code used to calculate internal forces on particles");
+	RNA_def_property_update(prop, 0, "rna_Particle_reset");
+
 	prop = RNA_def_property(srna, "spring_force", PROP_FLOAT, PROP_NONE);
 	RNA_def_property_float_sdna(prop, NULL, "spring_k");
 	RNA_def_property_range(prop, 0.0f, 100.0f);
@@ -1186,7 +1199,7 @@ static void rna_def_fluid_settings(BlenderRNA *brna)
 	/* Double density relaxation */
 	prop = RNA_def_property(srna, "stiffness", PROP_FLOAT, PROP_NONE);
 	RNA_def_property_float_sdna(prop, NULL, "stiffness_k");
-	RNA_def_property_range(prop, 0.0f, 100.0f);
+	RNA_def_property_range(prop, 0.0f, 100000.0f);
 	RNA_def_property_ui_range(prop, 0.0f, 10.0f, 1, 3);
 	RNA_def_property_ui_text(prop, "Stiffness", "How incompressible the fluid is");
 	RNA_def_property_update(prop, 0, "rna_Particle_reset");
@@ -1201,7 +1214,7 @@ static void rna_def_fluid_settings(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "rest_density", PROP_FLOAT, PROP_NONE);
 	RNA_def_property_float_sdna(prop, NULL, "rest_density");
-	RNA_def_property_range(prop, 0.0f, 100.0f);
+	RNA_def_property_range(prop, 0.0f, 10000.0f);
 	RNA_def_property_ui_range(prop, 0.0f, 2.0f, 1, 3);
 	RNA_def_property_ui_text(prop, "Rest Density", "Fluid rest density");
 	RNA_def_property_update(prop, 0, "rna_Particle_reset");
@@ -2281,7 +2294,7 @@ static void rna_def_particle_settings(BlenderRNA *brna)
 
 	/* physical properties */
 	prop = RNA_def_property(srna, "mass", PROP_FLOAT, PROP_NONE);
-	RNA_def_property_range(prop, 0.001f, 100000.0f);
+	RNA_def_property_range(prop, 0.00000001f, 100000.0f);
 	RNA_def_property_ui_range(prop, 0.01, 100, 1, 3);
 	RNA_def_property_ui_text(prop, "Mass", "Mass of the particles");
 	RNA_def_property_update(prop, 0, "rna_Particle_reset");