Maybe this will help - I wrote it to answer a similar question: http://developer.valvesoftware.com/wiki/Rotation_Tutorial
Jay > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Tony Paloma > Sent: Thursday, April 12, 2007 10:42 PM > To: [EMAIL PROTECTED] > Subject: [hlcoders] Rotating something about it's own axis > > This is a multipart message in MIME format. > -- > [ Picked text/plain from multipart/alternative ] I need help > rotating an entity about its own axis. Basically, what I want > to be able to do is add 90 degrees to the entity's y-axis > rotation. This works fine by simply doing a angles.x+=90 when > the entity's orientation matches that of the world's. > However, if the entity is tilted or aligned differently, this > doesn't give the desired result since it will rotate it 90 > degrees to the world's perspective. I have tried using > cross-products and vector multiplication, but everything I am > doing is wrong and not giving the right result. > > > > All I want to do is make a wheel aligned with a plane. If I > do VectorAngles(tr.plane.normal, angles) then apply the > angles, the wheel sticks out perpendicular to the plane > instead of running tangent to it. > Rotating by 90 degrees along the y-axis will fix this, but > only if the plane's "up" is the same as the world's "up". > There is some kind of vector math trick to get this to work > that I don't know. > > > > If any of you know how to solve this, please let me know. > Thanks a lot! > > -- > > > _______________________________________________ > To unsubscribe, edit your list preferences, or view the list > archives, please visit: > http://list.valvesoftware.com/mailman/listinfo/hlcoders > > _______________________________________________ To unsubscribe, edit your list preferences, or view the list archives, please visit: http://list.valvesoftware.com/mailman/listinfo/hlcoders