[osg-users] Get current Billboard ModelView matrix?

[Philipp Meyer]

Hi,


> If you only need the movement towards/away from you, you can use the
> previous frames depth and perform difference computation based on the
> difference of the linear depth. 


Im not exactly sure what you mean here. Are you talking about rendering the depth of each frame to a texture and comparing the values with the next frame to compute the delta?

If so, wouldnt that be a pixel based approach again suffering the same problems as I mentioned earlier as a response to mp3butcher?


> I'd simply pass the view matrix inverse (pre frame) and calculate the
> modelmatrix via inverse_view * model_view_matrix.


That works, but only gives me the current modelMatrix. I need the modelMatrix of the previos frame though. Because objects can move in my scene, I can not calculate the old vertex position by simply using the current modelMatrix with the old viewMatrix.

Thank you!

Cheers,
Philipp

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