Actually return a normalized vector from shapecast

1 files changed, 5 insertions, 1 deletions

diff --git a/src/shared/lua_api/load_phys.cpp b/src/shared/lua_api/load_phys.cpp
index d20545e..a03c404 100644
--- a/src/shared/lua_api/load_phys.cpp
+++ b/src/shared/lua_api/load_phys.cpp
@@ -33,7 +33,11 @@ int shapecast(lua_State *L){
 	//printf("before getting results\n\tHasHit:%d\n\tHit:%f,%f,%f\n\tNor:%f,%f,%f\n",cb->hasHit() ? 1 : 0,hw.x(),hw.y(),hw.z(),hn.x(),hn.y(),hn.z());
 	World->convexSweepTest(cs,ft,tt,*cb,1.f);
 	hw = cb->m_hitPointWorld;
-	hn = cb->m_hitNormalWorld;
+	//Okay, turns out m_hitNormalWorld is not the normal of either of the shapes (although it's usually close):
+	//https://pybullet.org/Bullet/phpBB3/viewtopic.php?t=3538
+	//Not only is it not a normal of either of the shapes or the collision, it's not even a normalized vector, I got it's magnitude as low as 0.90 and as high as 1.11 in testing.
+	//So we have to normalize it once it comes out.
+	hn = cb->m_hitNormalWorld.normalized();
 	//printf("Got sweep results\n\tHasHit:%d\n\tHit:%f,%f,%f\n\tNor:%f,%f,%f\n",cb->hasHit() ? 1 : 0,hw.x(),hw.y(),hw.z(),hn.x(),hn.y(),hn.z());
 	lua_newtable(L);//{}
 	lua_pushboolean(L,cb->hasHit() ? 1 : 0);