Just reposting with correct subject thread. ;-)
On 26/10/2007, Chris Denham <[EMAIL PROTECTED]> wrote: > Hi Michele, > Thanks for this. You're probably right, I was floundering about a bit > in that snippet of code I sent. Robert's suggestion contained a much > neater solution - using the sign of the dot product of the vectors > between eye point and face normal. i.e. cull when this is negative. > (Convieniently, the node visitor gives you the eye point in local > coordinates). All this is neatly wrapped up in ClusterCullingCallback > class, so all I needed was one line of code to acheive my objective! > Cheers. > Chris. > > Date: Fri, 26 Oct 2007 13:32:53 +0200 > From: "Michele Bosi" <[EMAIL PROTECTED]> > Subject: Re: [osg-users] Backface culling for a group containing a > plane of linestrips. > To: "OpenSceneGraph Users" <[email protected]> > Message-ID: > <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="iso-8859-1" > > Hi Chris, > I did something similar once, I am not totally sure but I think that the > vector should be multiplied before the matrix and that you need to multiply > only the direction component without the position. Once you have the > direction transformed in camera space to see if it faces the camera you > should only need to test if the Z component is > 0 (assuming a right handed > reference system). > > Good luck, > Michele > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
