[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [24972] trunk/blender: BGE: ray casting works on soft body, the hit polygon is also returned.

[Benoit Bolsee]

Revision: 24972
          http://projects.blender.org/plugins/scmsvn/viewcvs.php?view=rev&root=bf-blender&revision=24972
Author:   ben2610
Date:     2009-11-28 18:30:34 +0100 (Sat, 28 Nov 2009)

Log Message:
-----------
BGE: ray casting works on soft body, the hit polygon is also returned. The modifications to Bullet have been reported to Bullet forum. Note: welding is completely disabled on soft body as it breaks the relationship between the soft body collision shape and the graphics mesh without bringing any additional stability (the reverse actually).

Modified Paths:
--------------
    trunk/blender/extern/bullet2/src/BulletCollision/BroadphaseCollision/btBroadphaseProxy.h
    trunk/blender/extern/bullet2/src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp
    trunk/blender/extern/bullet2/src/BulletCollision/CollisionShapes/btCollisionShape.h
    trunk/blender/source/gameengine/Converter/BL_BlenderDataConversion.cpp
    trunk/blender/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp

Modified: trunk/blender/extern/bullet2/src/BulletCollision/BroadphaseCollision/btBroadphaseProxy.h
===================================================================
--- trunk/blender/extern/bullet2/src/BulletCollision/BroadphaseCollision/btBroadphaseProxy.h	2009-11-28 17:20:42 UTC (rev 24971)
+++ trunk/blender/extern/bullet2/src/BulletCollision/BroadphaseCollision/btBroadphaseProxy.h	2009-11-28 17:30:34 UTC (rev 24972)
@@ -152,6 +152,10 @@
 	{
 		return (proxyType == STATIC_PLANE_PROXYTYPE);
 	}
+	static SIMD_FORCE_INLINE bool isSoftBody(int proxyType)
+	{
+		return (proxyType == SOFTBODY_SHAPE_PROXYTYPE);
+	}
 	
 }
 ;

Modified: trunk/blender/extern/bullet2/src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp
===================================================================
--- trunk/blender/extern/bullet2/src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp	2009-11-28 17:20:42 UTC (rev 24971)
+++ trunk/blender/extern/bullet2/src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp	2009-11-28 17:30:34 UTC (rev 24972)
@@ -31,6 +31,7 @@
 #include "LinearMath/btAabbUtil2.h"
 #include "LinearMath/btQuickprof.h"
 #include "LinearMath/btStackAlloc.h"
+#include "BulletSoftBody/btSoftBody.h"
 
 //#define USE_BRUTEFORCE_RAYBROADPHASE 1
 //RECALCULATE_AABB is slower, but benefit is that you don't need to call 'stepSimulation'  or 'updateAabbs' before using a rayTest
@@ -411,6 +412,31 @@
 					// restore
 					collisionObject->internalSetTemporaryCollisionShape(saveCollisionShape);
 				}
+			} else {
+				if (collisionShape->isSoftBody()) {
+					btSoftBody* softBody = static_cast<btSoftBody*>(collisionObject);
+					btSoftBody::sRayCast softResult;
+					if (softBody->rayTest(rayFromTrans.getOrigin(), rayToTrans.getOrigin(), softResult)) 
+					{
+						btCollisionWorld::LocalShapeInfo shapeInfo;
+						shapeInfo.m_shapePart = 0;
+						shapeInfo.m_triangleIndex = softResult.index;
+						// get the normal
+						btVector3 normal = softBody->m_faces[softResult.index].m_normal;
+						btVector3 rayDir = rayToTrans.getOrigin() - rayFromTrans.getOrigin();
+						if (normal.dot(rayDir) > 0) {
+							// normal always point toward origin of the ray
+							normal = -normal;
+						}
+						btCollisionWorld::LocalRayResult rayResult
+							(collisionObject,
+							 &shapeInfo,
+							 normal,
+							 softResult.fraction);
+						bool	normalInWorldSpace = true;
+						resultCallback.addSingleResult(rayResult,normalInWorldSpace);
+					}
+				}
 			}
 		}
 	}

Modified: trunk/blender/extern/bullet2/src/BulletCollision/CollisionShapes/btCollisionShape.h
===================================================================
--- trunk/blender/extern/bullet2/src/BulletCollision/CollisionShapes/btCollisionShape.h	2009-11-28 17:20:42 UTC (rev 24971)
+++ trunk/blender/extern/bullet2/src/BulletCollision/CollisionShapes/btCollisionShape.h	2009-11-28 17:30:34 UTC (rev 24972)
@@ -72,6 +72,10 @@
 	{
 		return btBroadphaseProxy::isCompound(getShapeType());
 	}
+	SIMD_FORCE_INLINE bool	isSoftBody() const
+	{
+		return btBroadphaseProxy::isSoftBody(getShapeType());
+	}
 
 	///isInfinite is used to catch simulation error (aabb check)
 	SIMD_FORCE_INLINE bool isInfinite() const

Modified: trunk/blender/source/gameengine/Converter/BL_BlenderDataConversion.cpp
===================================================================
--- trunk/blender/source/gameengine/Converter/BL_BlenderDataConversion.cpp	2009-11-28 17:20:42 UTC (rev 24971)
+++ trunk/blender/source/gameengine/Converter/BL_BlenderDataConversion.cpp	2009-11-28 17:30:34 UTC (rev 24972)
@@ -1458,7 +1458,9 @@
 			objprop.m_soft_kAHR= blenderobject->bsoft->kAHR;			/* Anchors hardness [0,1] */
 			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_soft_welding = blenderobject->bsoft->welding;		/* welding */
+			/* disable welding: it doesn't bring any additional stability and it breaks the relation between soft body collision shape and graphic mesh */
+			objprop.m_soft_welding = 0.f;		
 			objprop.m_margin = blenderobject->bsoft->margin;
 			objprop.m_contactProcessingThreshold = 0.f;
 		} else

Modified: trunk/blender/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp
===================================================================
--- trunk/blender/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp	2009-11-28 17:20:42 UTC (rev 24971)
+++ trunk/blender/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp	2009-11-28 17:30:34 UTC (rev 24972)
@@ -1070,6 +1070,8 @@
 					rayCallback.m_hitTriangleIndex < shapeInfo->m_polygonIndexArray.size())
 				{
 					result.m_meshObject = shapeInfo->GetMesh();
+					// note for softbody: this assumes that the softbody shape uses the same triangle numbering 
+					// than the triangle mesh shape that was used to build it
 					result.m_polygon = shapeInfo->m_polygonIndexArray.at(rayCallback.m_hitTriangleIndex);
 
 					// Bullet returns the normal from "outside".
@@ -1078,8 +1080,14 @@
 					{
 						// mesh shapes are shared and stored in the shapeInfo
 						btTriangleMeshShape* triangleShape = shapeInfo->GetMeshShape();
-						if (triangleShape)
+
+						if (shape->isSoftBody()) 
 						{
+							// we can get the real normal directly from the body
+							btSoftBody* softBody = static_cast<btSoftBody*>(rayCallback.m_collisionObject);
+							rayCallback.m_hitNormalWorld = softBody->m_faces[rayCallback.m_hitTriangleIndex].m_normal;
+						} else if (triangleShape)
+						{
 							// this code is copied from Bullet 
 							btVector3 triangle[3];
 							const unsigned char *vertexbase;