Absolute rotation of a mesh

Will Piovano · Post by **Will Piovano** » Mon Oct 30, 2006 3:24 am

Is it possible to rotate a mesh with absolute values? When I rotate a die around a board, as soon as I perform a sideways rotation, the axis gets shifted and I can no longer roll in the correct direction.

Thanks,

Will

sgt_pinky · Post by **sgt_pinky** » Mon Oct 30, 2006 3:48 am

If you are going to do more complex rotations, you need to dig out a maths book and read up on transformation matrices. Or Google it, whatever. When you apply a rotation to an object, what you are actually doing is creating a 4x4 matrix that transforms the coordinates of each vertex (in world space).

Pinky

CodeDog · Post by **CodeDog** » Mon Oct 30, 2006 8:01 am

It can also be done with spherical trigonometry.

sgt_pinky · Post by **sgt_pinky** » Mon Oct 30, 2006 8:21 am

It can also be done in an abstract coordinate system of any number of dimensions - but it's unlike that's what he will do, isn't it?!

mystic jimbo · Post by **mystic jimbo** » Mon Oct 30, 2006 3:38 pm

I am struggling with this as well. Say I have a simple cube and I want it roll correctly towards a certain direction, how would I figure out how to rotate it? When I rotate just by a single axis it works OK, but when I add another axis it all goes to nuts.

I have tried to google, but I can't find a good example.

mystic jimbo · Post by **mystic jimbo** » Mon Oct 30, 2006 4:58 pm

This topic got me going:

http://irrlicht.sourceforge.net/phpBB2/ ... hp?t=12629

I still don't have rolling, but the cube now turns to right direction...