[Bf-blender-cvs] [28f173b] hair_immediate_fixes: Added a calculation function for the fictitious forces introduced by moving hair root reference frames.
Lukas Tönne
noreply at git.blender.org
Mon Sep 15 14:23:25 CEST 2014
Commit: 28f173b3e7b84c12dce5f2fd88c81818c253ec74
Author: Lukas Tönne
Date: Mon Sep 15 14:18:40 2014 +0200
Branches: hair_immediate_fixes
https://developer.blender.org/rB28f173b3e7b84c12dce5f2fd88c81818c253ec74
Added a calculation function for the fictitious forces introduced by
moving hair root reference frames.
This calculates Euler, Coriolis and Centrifugal forces which result
from describing hair in a moving reference frame.
http://en.wikipedia.org/wiki/Fictitious_force
===================================================================
M source/blender/blenlib/BLI_math_matrix.h
M source/blender/blenlib/intern/math_matrix.c
M source/blender/editors/object/object_bake_api.c
M source/blender/physics/intern/implicit.h
M source/blender/physics/intern/implicit_blender.c
===================================================================
diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 7bcaab1..178c83b 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -121,7 +121,8 @@ void mul_m3_fl(float R[3][3], float f);
void mul_m4_fl(float R[4][4], float f);
void mul_mat3_m4_fl(float R[4][4], float f);
-void negate_m3(float R[4][4]);
+void negate_m3(float R[3][3]);
+void negate_mat3_m4(float R[4][4]);
void negate_m4(float R[4][4]);
bool invert_m3_ex(float m[3][3], const float epsilon);
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index 09c581a..a7e0484 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -612,7 +612,16 @@ void mul_mat3_m4_fl(float m[4][4], float f)
m[i][j] *= f;
}
-void negate_m3(float m[4][4])
+void negate_m3(float m[3][3])
+{
+ int i, j;
+
+ for (i = 0; i < 3; i++)
+ for (j = 0; j < 3; j++)
+ m[i][j] *= -1.0f;
+}
+
+void negate_mat3_m4(float m[4][4])
{
int i, j;
diff --git a/source/blender/editors/object/object_bake_api.c b/source/blender/editors/object/object_bake_api.c
index fd4db4f..2d8de6c 100644
--- a/source/blender/editors/object/object_bake_api.c
+++ b/source/blender/editors/object/object_bake_api.c
@@ -768,7 +768,7 @@ static int bake(
normalize_m4_m4(highpoly[i].rotmat, highpoly[i].imat);
zero_v3(highpoly[i].rotmat[3]);
if (is_negative_m4(highpoly[i].rotmat))
- negate_m3(highpoly[i].rotmat);
+ negate_mat3_m4(highpoly[i].rotmat);
i++;
}
diff --git a/source/blender/physics/intern/implicit.h b/source/blender/physics/intern/implicit.h
index c7becfd..2577174 100644
--- a/source/blender/physics/intern/implicit.h
+++ b/source/blender/physics/intern/implicit.h
@@ -118,17 +118,27 @@ void BPH_mass_spring_add_constraint_ndof2(struct Implicit_Data *data, int index,
bool BPH_mass_spring_solve(struct Implicit_Data *data, float dt);
void BPH_mass_spring_apply_result(struct Implicit_Data *data);
+/* Clear the force vector at the beginning of the time step */
void BPH_mass_spring_force_clear(struct Implicit_Data *data);
+/* Fictitious forces introduced by moving coordinate systems */
+void BPH_mass_spring_force_reference_frame(struct Implicit_Data *data, int index);
+/* Simple uniform gravity force */
void BPH_mass_spring_force_gravity(struct Implicit_Data *data, const float g[3]);
+/* Global drag force (velocity damping) */
void BPH_mass_spring_force_drag(struct Implicit_Data *data, float drag);
+/* Wind force, acting on a face */
void BPH_mass_spring_force_face_wind(struct Implicit_Data *data, int v1, int v2, int v3, int v4, const float (*winvec)[3]);
+/* Wind force, acting on an edge */
void BPH_mass_spring_force_edge_wind(struct Implicit_Data *data, int v1, int v2, const float (*winvec)[3]);
+/* Linear spring force between two points */
bool BPH_mass_spring_force_spring_linear(struct Implicit_Data *data, int i, int j, int spring_index, float restlen,
float stiffness, float damping, bool no_compress, float clamp_force,
float r_f[3], float r_dfdx[3][3], float r_dfdv[3][3]);
+/* 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, int spring_index, float restlen,
float kb, float cb,
float r_f[3], float r_dfdx[3][3], float r_dfdv[3][3]);
+/* Global goal spring */
bool BPH_mass_spring_force_spring_goal(struct Implicit_Data *data, int i, int spring_index, const float goal_x[3], const float goal_v[3],
float stiffness, float damping,
float r_f[3], float r_dfdx[3][3], float r_dfdv[3][3]);
diff --git a/source/blender/physics/intern/implicit_blender.c b/source/blender/physics/intern/implicit_blender.c
index f493055..1317230 100644
--- a/source/blender/physics/intern/implicit_blender.c
+++ b/source/blender/physics/intern/implicit_blender.c
@@ -580,6 +580,20 @@ BLI_INLINE void outerproduct(float r[3][3], const float a[3], const float b[3])
mul_v3_v3fl(r[1], a, b[1]);
mul_v3_v3fl(r[2], a, b[2]);
}
+
+BLI_INLINE void cross_m3_v3m3(float r[3][3], const float v[3], float m[3][3])
+{
+ cross_v3_v3v3(r[0], v, m[0]);
+ cross_v3_v3v3(r[1], v, m[1]);
+ cross_v3_v3v3(r[2], v, m[2]);
+}
+
+BLI_INLINE void cross_v3_identity(float r[3][3], const float v[3])
+{
+ r[0][0] = 0.0f; r[1][0] = v[2]; r[2][0] = -v[1];
+ r[0][1] = -v[2]; r[1][1] = 0.0f; r[2][1] = v[0];
+ r[0][2] = v[1]; r[1][2] = -v[0]; r[2][2] = 0.0f;
+}
/////////////////////////////////////////////////////////////////
///////////////////////////
@@ -798,14 +812,14 @@ DO_INLINE void subadd_bfmatrixS_bfmatrixS( fmatrix3x3 *to, fmatrix3x3 *from, flo
// simulator start
///////////////////////////////////////////////////////////////////
typedef struct RootTransform {
- float loc[3];
- float rot[3][3];
+ float loc[3]; /* translation in world space */
+ float rot[3][3]; /* rotation from root to world space */
- float vel[3];
- float omega[3];
+ float vel[3]; /* velocity in root space */
+ float omega[3]; /* angular velocity in root space */
- float acc[3];
- float domega_dt[3];
+ float acc[3]; /* acceleration in root space */
+ float domega_dt[3]; /* angular acceleration in root space */
} RootTransform;
typedef struct Implicit_Data {
@@ -1715,6 +1729,50 @@ void BPH_mass_spring_force_clear(Implicit_Data *data)
init_bfmatrix(data->dFdV, ZERO);
}
+void BPH_mass_spring_force_reference_frame(Implicit_Data *data, int index)
+{
+#ifdef CLOTH_ROOT_FRAME
+ RootTransform *root = &data->root[index];
+ float f[3], dfdx[3][3], dfdv[3][3];
+ float euler[3], coriolis[3], centrifugal[3], rotvel[3];
+ float deuler[3][3], dcoriolis[3][3], dcentrifugal[3][3], drotvel[3][3];
+
+ cross_v3_v3v3(euler, root->domega_dt, data->X[index]);
+ cross_v3_v3v3(coriolis, root->omega, data->V[index]);
+ mul_v3_fl(coriolis, 2.0f);
+ cross_v3_v3v3(rotvel, root->omega, data->X[index]);
+ cross_v3_v3v3(centrifugal, root->omega, rotvel);
+
+ sub_v3_v3v3(f, root->acc, euler);
+ sub_v3_v3(f, coriolis);
+ sub_v3_v3(f, centrifugal);
+
+ mul_m3_v3(data->M[index].m, f); /* F = m * a */
+
+ cross_v3_identity(deuler, root->domega_dt);
+ cross_v3_identity(dcoriolis, root->omega);
+ mul_m3_fl(dcoriolis, 2.0f);
+ cross_v3_identity(drotvel, root->omega);
+ cross_m3_v3m3(dcentrifugal, root->omega, drotvel);
+
+ add_m3_m3m3(dfdx, deuler, dcentrifugal);
+ negate_m3(dfdx);
+ mul_m3_m3m3(dfdx, data->M[index].m, dfdx);
+
+ copy_m3_m3(dfdv, dcoriolis);
+ negate_m3(dfdv);
+ mul_m3_m3m3(dfdv, data->M[index].m, dfdv);
+
+ add_v3_v3(data->F[index], f);
+ add_m3_m3m3(data->dFdX[index].m, data->dFdX[index].m, dfdx);
+ add_m3_m3m3(data->dFdV[index].m, data->dFdV[index].m, dfdv);
+
+#else
+ (void)data;
+ (void)index;
+#endif
+}
+
void BPH_mass_spring_force_gravity(Implicit_Data *data, const float g[3])
{
int i, numverts = data->M[0].vcount;
@@ -2026,9 +2084,7 @@ bool BPH_mass_spring_force_spring_goal(Implicit_Data *data, int i, int UNUSED(sp
dfdv_damp(dfdv, dir, damping);
add_v3_v3(data->F[i], f);
-
add_m3_m3m3(data->dFdX[i].m, data->dFdX[i].m, dfdx);
-
add_m3_m3m3(data->dFdV[i].m, data->dFdV[i].m, dfdv);
if (r_f) copy_v3_v3(r_f, f);
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