BGE soft body: give access to the soft body collision margin in the Advanced panel. By default the collision margin is set to 0.25, which causes the soft body to somewhat float above the ground. You can decrease this value to get more realistic collision. Note that the algorithm may become unstable with lower margin.

4 files changed, 16 insertions, 4 deletions

diff --git a/source/blender/makesdna/DNA_object_force.h b/source/blender/makesdna/DNA_object_force.h
index e8e865a533c..dc449a64c6d 100644
--- a/source/blender/makesdna/DNA_object_force.h
+++ b/source/blender/makesdna/DNA_object_force.h
@@ -120,6 +120,7 @@ typedef struct BulletSoftBody {
 	int		collisionflags;	/* Vertex/Face or Signed Distance Field(SDF) or Clusters, Soft versus Soft or Rigid */
 	int		numclusteriterations;	/* number of iterations to refine collision clusters*/
 	float	welding;		/* welding limit to remove duplicate/nearby vertices, 0.0..0.01 */
+	float   margin;			/* margin specific to softbody */
 } BulletSoftBody;
 
 /* BulletSoftBody.flag */
diff --git a/source/blender/src/buttons_logic.c b/source/blender/src/buttons_logic.c
index 2cda73eaef3..2f8933b593b 100644
--- a/source/blender/src/buttons_logic.c
+++ b/source/blender/src/buttons_logic.c
@@ -3141,8 +3141,14 @@ static uiBlock *advanced_bullet_menu(void *arg_ob)
 			uiBlockEndAlign(block);
 			yco -= 20;
 			xco = 0;
-			uiDefButF(block, NUMSLI, 0, "Welding ", 
-				xco, yco, 360, 19, &ob->bsoft->welding, 0.f, 0.01f, 10, 4, 
+			if (ob->bsoft->margin < 0.001f)
+				ob->bsoft->margin = 0.25f;
+			uiDefButF(block, NUM, 0, "Margin", 
+					xco, yco, 180, 19, &ob->bsoft->margin, 0.001, 1.0, 1, 0, 
+					"Collision margin for soft body. Small value makes the algorithm unstable");
+
+			uiDefButF(block, NUM, 0, "Welding ", 
+				xco+=180, yco, 180, 19, &ob->bsoft->welding, 0.f, 0.01f, 10, 4, 
 				"Welding threshold: distance between nearby vertices to be considered equal => set to 0.0 to disable welding test and speed up scene loading (ok if the mesh has no duplicates)");
 
 			/*
diff --git a/source/gameengine/Converter/BL_BlenderDataConversion.cpp b/source/gameengine/Converter/BL_BlenderDataConversion.cpp
index d4cc047d5e3..13aac74edca 100644
--- a/source/gameengine/Converter/BL_BlenderDataConversion.cpp
+++ b/source/gameengine/Converter/BL_BlenderDataConversion.cpp
@@ -1456,7 +1456,7 @@ void BL_CreatePhysicsObjectNew(KX_GameObject* gameobj,
 			objprop.m_soft_collisionflags= blenderobject->bsoft->collisionflags;	/* Vertex/Face or Signed Distance Field(SDF) or Clusters, Soft versus Soft or Rigid */
 			objprop.m_soft_numclusteriterations= blenderobject->bsoft->numclusteriterations;	/* number of iterations to refine collision clusters*/
 			objprop.m_soft_welding = blenderobject->bsoft->welding;		/* welding */
-		
+			objprop.m_margin = blenderobject->bsoft->margin;
 		} else
 		{
 			objprop.m_gamesoftFlag = OB_BSB_BENDING_CONSTRAINTS | OB_BSB_SHAPE_MATCHING | OB_BSB_AERO_VPOINT;
@@ -1496,6 +1496,7 @@ void BL_CreatePhysicsObjectNew(KX_GameObject* gameobj,
 			objprop.m_soft_collisionflags= OB_BSB_COL_SDF_RS + OB_BSB_COL_VF_SS;
 			objprop.m_soft_numclusteriterations= 16;
 			objprop.m_soft_welding = 0.f;
+			objprop.m_margin = 0.f;
 		}
 	}
 
diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
index 7302c47f4bf..6b00011b693 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
@@ -296,7 +296,11 @@ void CcdPhysicsController::CreateRigidbody()
 			}
 
 		}
-
+		if (m_cci.m_margin > 0.f)
+		{
+			psb->getCollisionShape()->setMargin(m_cci.m_margin);
+			psb->updateBounds();
+		}
 	
 		
 		m_object = psb;