From 7d9bcafda8649dee657a727bc2f5d1a4c6beb609 Mon Sep 17 00:00:00 2001
From: Erwin Coumans <erwin.coumans@gmail.com>
Date: Mon, 10 Aug 2020 17:00:19 -0700
Subject: [PATCH] when using stablePDPlugin, approximate inertia by box for
 unsupported shapes.

---
 .../plugins/stablePDPlugin/BulletConversion.cpp | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/examples/SharedMemory/plugins/stablePDPlugin/BulletConversion.cpp b/examples/SharedMemory/plugins/stablePDPlugin/BulletConversion.cpp
index 224afaf9a..cb6bacd33 100644
--- a/examples/SharedMemory/plugins/stablePDPlugin/BulletConversion.cpp
+++ b/examples/SharedMemory/plugins/stablePDPlugin/BulletConversion.cpp
@@ -93,6 +93,7 @@ bool btExtractJointBodyFromTempLinks(btAlignedObjectArray<TempLink>& links, Eige
 					collisionShape = compound->getChildShape(0);
 				}
 			}
+			
 			switch (collisionShape->getShapeType())
 			{
 			case BOX_SHAPE_PROXYTYPE:
@@ -102,6 +103,7 @@ bool btExtractJointBodyFromTempLinks(btAlignedObjectArray<TempLink>& links, Eige
 				param0 = box->getHalfExtentsWithMargin()[0] * 2;
 				param1 = box->getHalfExtentsWithMargin()[1] * 2;
 				param2 = box->getHalfExtentsWithMargin()[2] * 2;
+				
 				break;
 			}
 			case SPHERE_SHAPE_PROXYTYPE:
@@ -124,7 +126,20 @@ bool btExtractJointBodyFromTempLinks(btAlignedObjectArray<TempLink>& links, Eige
 			}
 			default:
 			{
-				btAssert(0);
+				//approximate by its box
+				btTransform identity;
+				identity.setIdentity();
+				btVector3 aabbMin, aabbMax;
+				collisionShape->getAabb(identity, aabbMin, aabbMax);
+				btVector3 halfExtents = (aabbMax - aabbMin) * btScalar(0.5);
+				btScalar margin = collisionShape->getMargin();
+				btScalar lx = btScalar(2.) * (halfExtents.x() + margin);
+				btScalar ly = btScalar(2.) * (halfExtents.y() + margin);
+				btScalar lz = btScalar(2.) * (halfExtents.z() + margin);
+				param0 = lx;
+				param1 = ly;
+				param2 = lz;
+				shapeType = cShape::eShapeBox;
 			}
 			}
 		}