Commit: bb32d9240fe17a7c239417701e69f00fa165906b
Author: Luca Rood
Date: Thu Dec 15 21:03:12 2016 -0200
Branches: cloth-improvements
https://developer.blender.org/rBbb32d9240fe17a7c239417701e69f00fa165906b
Implement angular plasticity (has issues)
Same issues as the previous structural plasticity commit.
===================================================================
M release/scripts/startup/bl_ui/properties_physics_cloth.py
M source/blender/blenkernel/BKE_cloth.h
M source/blender/blenkernel/intern/cloth.c
M source/blender/physics/intern/BPH_mass_spring.cpp
M source/blender/physics/intern/implicit.h
M source/blender/physics/intern/implicit_blender.c
===================================================================
diff --git a/release/scripts/startup/bl_ui/properties_physics_cloth.py
b/release/scripts/startup/bl_ui/properties_physics_cloth.py
index d49d88c..fc14855 100644
--- a/release/scripts/startup/bl_ui/properties_physics_cloth.py
+++ b/release/scripts/startup/bl_ui/properties_physics_cloth.py
@@ -103,6 +103,8 @@ class PHYSICS_PT_cloth(PhysicButtonsPanel, Panel):
layout.prop(cloth, "structural_plasticity")
layout.prop(cloth, "structural_yield_factor")
+ layout.prop(cloth, "bending_plasticity")
+ layout.prop(cloth, "bending_yield_factor")
split = layout.split()
diff --git a/source/blender/blenkernel/BKE_cloth.h
b/source/blender/blenkernel/BKE_cloth.h
index a7a13cd..53c2f27 100644
--- a/source/blender/blenkernel/BKE_cloth.h
+++ b/source/blender/blenkernel/BKE_cloth.h
@@ -140,6 +140,7 @@ typedef struct ClothSpring {
float restlen; /* The original length of the spring */
float restang; /* The original angle of the bending springs */
float lenfact; /* Factor of restlen used for plasticity */
+ float angoffset; /* Offset of restang used for plasticity */
int type; /* types defined in BKE_cloth.h ("springType")
*/
int flags; /* defined in BKE_cloth.h, e.g. deactivated due
to tearing */
float stiffness; /* stiffness factor from the vertex groups */
diff --git a/source/blender/blenkernel/intern/cloth.c
b/source/blender/blenkernel/intern/cloth.c
index d0b9d6b..1d4aef2 100644
--- a/source/blender/blenkernel/intern/cloth.c
+++ b/source/blender/blenkernel/intern/cloth.c
@@ -1634,6 +1634,7 @@ static int cloth_build_springs ( ClothModifierData *clmd,
DerivedMesh *dm )
spring->lenfact = 1.0f;
spring->restang =
spring_angle(cloth->verts, spring->ij, spring->kl, spring->pa, spring->pb,
spring->la, spring->lb);
+ spring->angoffset = 0.0f;
spring->stiffness =
(cloth->verts[spring->ij].bend_stiff + cloth->verts[spring->kl].bend_stiff) /
2.0f;
diff --git a/source/blender/physics/intern/BPH_mass_spring.cpp
b/source/blender/physics/intern/BPH_mass_spring.cpp
index eff4a1c..a8b1a61 100644
--- a/source/blender/physics/intern/BPH_mass_spring.cpp
+++ b/source/blender/physics/intern/BPH_mass_spring.cpp
@@ -434,10 +434,10 @@ BLI_INLINE void cloth_calc_spring_force(ClothModifierData
*clmd, ClothSpring *s,
s->flags |= CLOTH_SPRING_FLAG_NEEDED;
scaling = parms->bending + s->stiffness * fabsf(parms->max_bend
- parms->bending);
- k = scaling * s->restlen * 0.1f; /* multiplying by 0.1, just to
scale the forces to more reasonable values */
+ k = scaling * s->restlen * s->lenfact * 0.1f; /* multiplying by
0.1, just to scale the forces to more reasonable values */
- BPH_mass_spring_force_spring_angular(data, s->ij, s->kl, s->pa,
s->pb, s->la, s->lb,
- s->restang, k,
parms->bending_damping);
+ BPH_mass_spring_force_spring_angular(data, s->ij, s->kl, s->pa,
s->pb, s->la, s->lb, s->restang, &s->angoffset,
+ k, parms->bending_damping,
parms->bend_plasticity, parms->bend_yield_fact * M_PI * 2);
#endif
}
else if (s->type & CLOTH_SPRING_TYPE_BENDING_HAIR) {
diff --git a/source/blender/physics/intern/implicit.h
b/source/blender/physics/intern/implicit.h
index 0146961..02d07c0 100644
--- a/source/blender/physics/intern/implicit.h
+++ b/source/blender/physics/intern/implicit.h
@@ -119,7 +119,8 @@ bool BPH_mass_spring_force_spring_linear(struct
Implicit_Data *data, int i, int
bool no_compress, float clamp_force,
float plasticity, float yield_fact);
/* Angular spring force between two polygons */
bool BPH_mass_spring_force_spring_angular(struct Implicit_Data *data, int i,
int j, int *i_a, int *i_b, int len_a, int len_b,
- float restang, float stiffness,
float damping);
+ float restangorig, float *angoffset,
float stiffness, float damping,
+ float plasticity, float yield_ang);
/* Bending force, forming a triangle at the base of two structural springs */
bool BPH_mass_spring_force_spring_bending(struct Implicit_Data *data, int i,
int j, float restlen,
float kb, float cb);
diff --git a/source/blender/physics/intern/implicit_blender.c
b/source/blender/physics/intern/implicit_blender.c
index cc388eb..d91136b 100644
--- a/source/blender/physics/intern/implicit_blender.c
+++ b/source/blender/physics/intern/implicit_blender.c
@@ -1752,19 +1752,37 @@ BLI_INLINE bool spring_angle(Implicit_Data *data, int
i, int j, int *i_a, int *i
/* Angular springs roughly based on the bending model proposed by Baraff and
Witkin in "Large Steps in Cloth Simulation" */
bool BPH_mass_spring_force_spring_angular(Implicit_Data *data, int i, int j,
int *i_a, int *i_b, int len_a, int len_b,
- float restang, float stiffness,
float damping)
+ float restangorig, float *angoffset,
float stiffness, float damping,
+ float plasticity, float yield_ang)
{
float angle, dir_a[3], dir_b[3], vel_a[3], vel_b[3];
float f_a[3], f_b[3], f_e[3];
float force;
+ float restang;
int x;
+ restang = restangorig + *angoffset;
+
spring_angle(data, i, j, i_a, i_b, len_a, len_b,
dir_a, dir_b, &angle, vel_a, vel_b);
/* spring force */
force = stiffness * (angle - restang);
+ /* compute plasticity offset */
+ if (angle > restang) {
+ if (angle - restang > yield_ang) {
+ restang += (angle - restang - yield_ang) * plasticity;
+ *angoffset = restang - restangorig;
+ }
+ }
+ else if (angle < restang) {
+ if (restang - angle > yield_ang) {
+ restang -= (restang - angle - yield_ang) * plasticity;
+ *angoffset = restang - restangorig;
+ }
+ }
+
/* damping force */
force += -damping * (dot_v3v3(vel_a, dir_a) + dot_v3v3(vel_b, dir_b));
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