Fix T51703: Rigid body with delta transform jumps when transforming

When doing any transformation on a rigid body object that has delta
transforms, the object would be offset by the amount of the delta
transform.

2 files changed, 41 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/rigidbody.c b/source/blender/blenkernel/intern/rigidbody.c
index c18366d1b8a..e8c0cf53d0b 100644
--- a/source/blender/blenkernel/intern/rigidbody.c
+++ b/source/blender/blenkernel/intern/rigidbody.c
@@ -1486,24 +1486,60 @@ void BKE_rigidbody_sync_transforms(RigidBodyWorld *rbw, Object *ob, float ctime)
 void BKE_rigidbody_aftertrans_update(Object *ob, float loc[3], float rot[3], float quat[4], float rotAxis[3], float rotAngle)
 {
 	RigidBodyOb *rbo = ob->rigidbody_object;
+	bool correct_delta = !(rbo->flag & RBO_FLAG_KINEMATIC || rbo->type == RBO_TYPE_PASSIVE);
 
 	/* return rigid body and object to their initial states */
 	copy_v3_v3(rbo->pos, ob->loc);
 	copy_v3_v3(ob->loc, loc);
 
+	if (correct_delta) {
+		add_v3_v3(rbo->pos, ob->dloc);
+	}
+
 	if (ob->rotmode > 0) {
-		eulO_to_quat(rbo->orn, ob->rot, ob->rotmode);
+		float qt[4];
+		eulO_to_quat(qt, ob->rot, ob->rotmode);
+
+		if (correct_delta) {
+			float dquat[4];
+			eulO_to_quat(dquat, ob->drot, ob->rotmode);
+
+			mul_qt_qtqt(rbo->orn, dquat, qt);
+		}
+		else {
+			copy_qt_qt(rbo->orn, qt);
+		}
+
 		copy_v3_v3(ob->rot, rot);
 	}
 	else if (ob->rotmode == ROT_MODE_AXISANGLE) {
-		axis_angle_to_quat(rbo->orn, ob->rotAxis, ob->rotAngle);
+		float qt[4];
+		axis_angle_to_quat(qt, ob->rotAxis, ob->rotAngle);
+
+		if (correct_delta) {
+			float dquat[4];
+			axis_angle_to_quat(dquat, ob->drotAxis, ob->drotAngle);
+
+			mul_qt_qtqt(rbo->orn, dquat, qt);
+		}
+		else {
+			copy_qt_qt(rbo->orn, qt);
+		}
+
 		copy_v3_v3(ob->rotAxis, rotAxis);
 		ob->rotAngle = rotAngle;
 	}
 	else {
-		copy_qt_qt(rbo->orn, ob->quat);
+		if (correct_delta) {
+			mul_qt_qtqt(rbo->orn, ob->dquat, ob->quat);
+		}
+		else {
+			copy_qt_qt(rbo->orn, ob->quat);
+		}
+
 		copy_qt_qt(ob->quat, quat);
 	}
+
 	if (rbo->physics_object) {
 		/* allow passive objects to return to original transform */
 		if (rbo->type == RBO_TYPE_PASSIVE)
diff --git a/source/blender/editors/transform/transform_conversions.c b/source/blender/editors/transform/transform_conversions.c
index ba474e93b70..1eb9b3caa3e 100644
--- a/source/blender/editors/transform/transform_conversions.c
+++ b/source/blender/editors/transform/transform_conversions.c
@@ -5349,7 +5349,8 @@ static void ObjectToTransData(TransInfo *t, TransData *td, Object *ob)
 			}
 			/* update object's loc/rot to get current rigid body transform */
 			mat4_to_loc_rot_size(ob->loc, rot, scale, ob->obmat);
-			BKE_object_mat3_to_rot(ob, rot, false);
+			sub_v3_v3(ob->loc, ob->dloc);
+			BKE_object_mat3_to_rot(ob, rot, false); /* drot is already corrected here */
 		}
 	}