Physics Simulation Forum


All times are UTC

Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Mon Feb 18, 2013 10:50 am 

Joined: Tue Oct 24, 2006 11:52 pm
Posts: 83
Location: Australia

I've just spent some time debugging a bullet problem - when falling down on one particular spot the kart would be shot up high into the sky. Reason is that m_hitNormalInWorld in btVehicleRaycasterResult is not normalised. While I knew that this value is not normalised (I normalise it in my code when using it), the problem is that this value is actually used without normalisation in btRaycastVehicle:
                wheel.m_raycastInfo.m_contactNormalWS  = rayResults.m_hitNormalInWorld;
                btVector3 impulse = wheel.m_raycastInfo.m_contactNormalWS * suspensionForce * step;

Normalising m_contactNormalWS fixed the problem for us, but I think it would be good to fix this in bullet as well. I guess the reason that this only happens at one spot is that the triangle the kart was falling on is big.

Now we have used the code without normalisation for years now, and never noticed a problem - were we just lucky (in that we apparently never fell onto a big triangle)? Or are we perhaps introducing some kind of problem with the normalisation?


Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC

Who is online

Users browsing this forum: Baidu [Spider], Bing [Bot], Google [Bot] and 14 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group