[Bf-blender-cvs] [bc8ae58727b] master: Copy Transforms: implement Remove Target Shear and more Mix options.

Alexander Gavrilov noreply at git.blender.org
Fri Jul 2 14:15:21 CEST 2021


Commit: bc8ae58727bf078df1fc5803a9de5c9eb984aeb7
Author: Alexander Gavrilov
Date:   Wed Nov 4 19:29:27 2020 +0300
Branches: master
https://developer.blender.org/rBbc8ae58727bf078df1fc5803a9de5c9eb984aeb7

Copy Transforms: implement Remove Target Shear and more Mix options.

This constraint can be naturally viewed as a prototype for a future
4x4 matrix math node (or subset thereof), since its basic semantics
already is matrix assignment. Thus it makes sense to add math options
to this constraint to increase flexibility in the meantime.

This patch adds support for several operations that would be useful:

- An option to remove shear in the incoming target matrix.

  Shear is known to cause issues for various mathematical operations,
  so an option to remove it at key points is useful.

  Constraints based on Euler like Copy Rotation and Limit Rotation
  already have always enabled shear removal built in, because their
  math doesn't work correctly with shear.

  In the future node system shear removal would be a separate node
  (and currently Limit Rotation can be used as a Remove Shear constraint).
  However removing shear from the result of the target space conversion
  before mixing (similar to Copy Rotation) has to be built into
  Copy Transforms itself as an option.

- More ways to combine the target and owner matrices.

  Similar to multiple Inherit Scale modes for parenting, there are
  multiple ways one may want to combine matrices based on context.
  This implements 3 variants for each of the Before/After modes
  (one of them already existing).

  - Full implements regular matrix multiplication as the most basic
    option. The downside is the risk of creating shear.
  - Aligned emulates the 'anti-shear' Aligned Inherit Scale mode,
    and basically uses Full for location, and Split for rotation/scale.
    (This choice already existed.)
  - Split Channels combines location, rotation and scale separately.

  Looking at D7547 there is demand for Split Channels in some cases,
  so I think it makes sense to include it in Copy Transforms too, so that
  the Mix menu items can be identical for it and the Action constraint.

Differential Revision: https://developer.blender.org/D9469

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

M	release/scripts/startup/bl_ui/properties_constraint.py
M	source/blender/blenkernel/intern/constraint.c
M	source/blender/blenlib/BLI_math_matrix.h
M	source/blender/blenlib/intern/math_matrix.c
M	source/blender/editors/transform/transform_convert.c
M	source/blender/makesdna/DNA_constraint_types.h
M	source/blender/makesrna/intern/rna_constraint.c
M	tests/python/bl_constraints.py

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

diff --git a/release/scripts/startup/bl_ui/properties_constraint.py b/release/scripts/startup/bl_ui/properties_constraint.py
index a88def34767..2a0cf56534c 100644
--- a/release/scripts/startup/bl_ui/properties_constraint.py
+++ b/release/scripts/startup/bl_ui/properties_constraint.py
@@ -505,6 +505,7 @@ class ConstraintButtonsPanel:
 
         self.target_template(layout, con)
 
+        layout.prop(con, "remove_target_shear")
         layout.prop(con, "mix_mode", text="Mix")
 
         self.space_template(layout, con)
diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 193b6d82d03..41da728fa5b 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -2235,17 +2235,47 @@ static void translike_evaluate(bConstraint *con, bConstraintOb *cob, ListBase *t
   bConstraintTarget *ct = targets->first;
 
   if (VALID_CONS_TARGET(ct)) {
+    float target_mat[4][4];
+
+    copy_m4_m4(target_mat, ct->matrix);
+
+    /* Remove the shear of the target matrix if enabled.
+     * Use Y as the axis since it's the natural default for bones. */
+    if (data->flag & TRANSLIKE_REMOVE_TARGET_SHEAR) {
+      orthogonalize_m4_stable(target_mat, 1, false);
+    }
+
+    /* Finally, combine the matrices. */
     switch (data->mix_mode) {
       case TRANSLIKE_MIX_REPLACE:
-        copy_m4_m4(cob->matrix, ct->matrix);
+        copy_m4_m4(cob->matrix, target_mat);
+        break;
+
+      /* Simple matrix multiplication. */
+      case TRANSLIKE_MIX_BEFORE_FULL:
+        mul_m4_m4m4(cob->matrix, target_mat, cob->matrix);
+        break;
+
+      case TRANSLIKE_MIX_AFTER_FULL:
+        mul_m4_m4m4(cob->matrix, cob->matrix, target_mat);
         break;
 
+      /* Aligned Inherit Scale emulation. */
       case TRANSLIKE_MIX_BEFORE:
-        mul_m4_m4m4_aligned_scale(cob->matrix, ct->matrix, cob->matrix);
+        mul_m4_m4m4_aligned_scale(cob->matrix, target_mat, cob->matrix);
         break;
 
       case TRANSLIKE_MIX_AFTER:
-        mul_m4_m4m4_aligned_scale(cob->matrix, cob->matrix, ct->matrix);
+        mul_m4_m4m4_aligned_scale(cob->matrix, cob->matrix, target_mat);
+        break;
+
+      /* Fully separate handling of channels. */
+      case TRANSLIKE_MIX_BEFORE_SPLIT:
+        mul_m4_m4m4_split_channels(cob->matrix, target_mat, cob->matrix);
+        break;
+
+      case TRANSLIKE_MIX_AFTER_SPLIT:
+        mul_m4_m4m4_split_channels(cob->matrix, cob->matrix, target_mat);
         break;
 
       default:
diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 54df88ca541..0c3a184d302 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -211,6 +211,7 @@ void mul_transposed_mat3_m4_v3(const float M[4][4], float r[3]);
 void mul_m3_v3_double(const float M[3][3], double r[3]);
 
 void mul_m4_m4m4_aligned_scale(float R[4][4], const float A[4][4], const float B[4][4]);
+void mul_m4_m4m4_split_channels(float R[4][4], const float A[4][4], const float B[4][4]);
 
 void mul_m3_fl(float R[3][3], float f);
 void mul_m4_fl(float R[4][4], float f);
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index 5eb0125062d..88bef854213 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -1290,6 +1290,9 @@ bool invert_m4_m4(float inverse[4][4], const float mat[4][4])
  * Combines transformations, handling scale separately in a manner equivalent
  * to the Aligned Inherit Scale mode, in order to avoid creating shear.
  * If A scale is uniform, the result is equivalent to ordinary multiplication.
+ *
+ * Note: this effectively takes output location from simple multiplication,
+ *       and uses mul_m4_m4m4_split_channels for rotation and scale.
  */
 void mul_m4_m4m4_aligned_scale(float R[4][4], const float A[4][4], const float B[4][4])
 {
@@ -1307,6 +1310,25 @@ void mul_m4_m4m4_aligned_scale(float R[4][4], const float A[4][4], const float B
   loc_rot_size_to_mat4(R, loc_r, rot_r, size_r);
 }
 
+/**
+ * Separately combines location, rotation and scale of the input matrices.
+ */
+void mul_m4_m4m4_split_channels(float R[4][4], const float A[4][4], const float B[4][4])
+{
+  float loc_a[3], rot_a[3][3], size_a[3];
+  float loc_b[3], rot_b[3][3], size_b[3];
+  float loc_r[3], rot_r[3][3], size_r[3];
+
+  mat4_to_loc_rot_size(loc_a, rot_a, size_a, A);
+  mat4_to_loc_rot_size(loc_b, rot_b, size_b, B);
+
+  add_v3_v3v3(loc_r, loc_a, loc_b);
+  mul_m3_m3m3_uniq(rot_r, rot_a, rot_b);
+  mul_v3_v3v3(size_r, size_a, size_b);
+
+  loc_rot_size_to_mat4(R, loc_r, rot_r, size_r);
+}
+
 /****************************** Linear Algebra *******************************/
 
 void transpose_m3(float R[3][3])
diff --git a/source/blender/editors/transform/transform_convert.c b/source/blender/editors/transform/transform_convert.c
index 99368a40225..00fd008151d 100644
--- a/source/blender/editors/transform/transform_convert.c
+++ b/source/blender/editors/transform/transform_convert.c
@@ -849,10 +849,13 @@ bool constraints_list_needinv(TransInfo *t, ListBase *list)
           /* Copy Transforms constraint only does this in the Before mode. */
           bTransLikeConstraint *data = (bTransLikeConstraint *)con->data;
 
-          if (ELEM(data->mix_mode, TRANSLIKE_MIX_BEFORE) &&
+          if (ELEM(data->mix_mode, TRANSLIKE_MIX_BEFORE, TRANSLIKE_MIX_BEFORE_FULL) &&
               ELEM(t->mode, TFM_ROTATION, TFM_TRANSLATION)) {
             return true;
           }
+          if (ELEM(data->mix_mode, TRANSLIKE_MIX_BEFORE_SPLIT) && ELEM(t->mode, TFM_ROTATION)) {
+            return true;
+          }
         }
         else if (con->type == CONSTRAINT_TYPE_ACTION) {
           /* The Action constraint only does this in the Before mode. */
diff --git a/source/blender/makesdna/DNA_constraint_types.h b/source/blender/makesdna/DNA_constraint_types.h
index 1e4fd2a70f2..25f72da2f15 100644
--- a/source/blender/makesdna/DNA_constraint_types.h
+++ b/source/blender/makesdna/DNA_constraint_types.h
@@ -316,8 +316,9 @@ typedef struct bSameVolumeConstraint {
 /* Copy Transform Constraint */
 typedef struct bTransLikeConstraint {
   struct Object *tar;
+  int flag;
   char mix_mode;
-  char _pad[7];
+  char _pad[3];
   /** MAX_ID_NAME-2. */
   char subtarget[64];
 } bTransLikeConstraint;
@@ -810,6 +811,12 @@ typedef enum eCopyScale_Flags {
   SIZELIKE_UNIFORM = (1 << 5),
 } eCopyScale_Flags;
 
+/* bTransLikeConstraint.flag */
+typedef enum eCopyTransforms_Flags {
+  /* Remove shear from the target matrix. */
+  TRANSLIKE_REMOVE_TARGET_SHEAR = (1 << 0),
+} eCopyTransforms_Flags;
+
 /* bTransLikeConstraint.mix_mode */
 typedef enum eCopyTransforms_MixMode {
   /* Replace rotation channel values. */
@@ -818,6 +825,14 @@ typedef enum eCopyTransforms_MixMode {
   TRANSLIKE_MIX_BEFORE = 1,
   /* Multiply the copied transformation on the right, with anti-shear scale handling. */
   TRANSLIKE_MIX_AFTER = 2,
+  /* Multiply the copied transformation on the left, handling loc/rot/scale separately. */
+  TRANSLIKE_MIX_BEFORE_SPLIT = 3,
+  /* Multiply the copied transformation on the right, handling loc/rot/scale separately. */
+  TRANSLIKE_MIX_AFTER_SPLIT = 4,
+  /* Multiply the copied transformation on the left, using simple matrix multiplication. */
+  TRANSLIKE_MIX_BEFORE_FULL = 5,
+  /* Multiply the copied transformation on the right, using simple matrix multiplication. */
+  TRANSLIKE_MIX_AFTER_FULL = 6,
 } eCopyTransforms_MixMode;
 
 /* bTransformConstraint.to/from */
diff --git a/source/blender/makesrna/intern/rna_constraint.c b/source/blender/makesrna/intern/rna_constraint.c
index d79f2c4d13f..d34885e1a68 100644
--- a/source/blender/makesrna/intern/rna_constraint.c
+++ b/source/blender/makesrna/intern/rna_constraint.c
@@ -1624,18 +1624,48 @@ static void rna_def_constraint_transform_like(BlenderRNA *brna)
        0,
        "Replace",
        "Replace the original transformation with copied"},
+      {0, "", 0, NULL, NULL},
+      {TRANSLIKE_MIX_BEFORE_FULL,
+       "BEFORE_FULL",
+       0,
+       "Before Original (Full)",
+       "Apply copied transformation before original, using simple matrix multiplication as if "
+       "the constraint target is a parent in Full Inherit Scale mode. "
+       "Will create shear when combining rotation and non-uniform scale"},
       {TRANSLIKE_MIX_BEFORE,
        "BEFORE",
        0,
-       "Before Original",
-       "Apply copied transformation before original, as if the constraint target is a parent. "
-       "Scale is handled specially to avoid creating shear"},
+       "Before Original (Aligned)",
+       "Apply copied transformation before original, as if the constraint target is a parent in "
+       "Aligned Inherit Scale mode. This effectively uses Full for location and Split Channels "
+       "for rotation and scale"},
+      {TRANSLIKE_MIX_BEFORE_SPLIT,
+       "BEFORE_SPLIT",
+       0,
+       "Before Original (Split Channels)",
+       "Apply copied transformation before original, handling location, rotation and scale "
+       "separately, similar to a sequence of three Copy constraints"},
+      {0, "", 0, NULL, NULL},
+      {TRANSLIKE_MIX_AFTER_FULL,
+       "AFTER_FULL",
+       0,
+       "After Original (Full)",
+       "Apply copied transformation after original, using simple matrix multiplication as if "
+       "the constraint target is a child in Full Inherit Scale mode. "
+       "Will create shear when combining rotation and non-uniform scale"},
       {TRANSLIKE_MIX_AFTER,
        "AFTER",
        0,
-       "After Original",
-       "Apply copied transformation after original, as if the constraint target is a child. "
-       "Scale is handled specially to avoid creating shear"},
+       "After Original (Aligned)",
+       "Apply copied transformation after original, as if the constraint target is a child in "
+       "Aligned Inherit Scale mode. This effectively uses Full for location and Split Channels "
+       "for rotation and scale"},
+      {TRANSLIKE_MIX_AFTER_SPLIT,
+       "AFTER_SPLIT",
+       0,
+       "After Original (Split Chan

@@ Diff output truncated at 10240 characters. @@



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