On 8/30/06, Jeff Kershner <[EMAIL PROTECTED]> wrote:
The TriangleFunctor will just pass along the xyz values that are in the osg::Geometry unchanged in order or sign.
I have noticed that the vertices x, y, z from a model come to the TriangleFunctor as x, z, -y. This is probably normal as OSG is Z pos up…
The OSG's plugins generally assume z up, y north, x east, and the OSG's camera manipulator also default to home position with z up, y north, x east.
This convention is the standard in vis-sim, but not all modelling apps follow it, and some graphics apps/users are used to y up. OpenGL being one of them, the eye coordinates are y up, z out of the screen, x to the right. The OSG's camera view matrices will take you from the z up coordinate frame to the y up OpenGL one.
The way I think about things is z up works well for world coordinates, when you think about your whole scene, and real world maps etc. However, when thinking about screen coordinates its useful to think a y up and x the right as this is what we are used to when draw xy graphs.
Robert.
Now if you load a model which had y up, z out the
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