Strange behavior with reverse axis and rendering

murray_b wrote at 2012-06-18 03:05:

Hi Objo

I have come across some strange behavor that I don't understand the reason for.

I recently reversed on the of the axis so that it matched the underlying data I am using.

ModelUpDirection=new Vector3D(0,0,-1);

This then draws the data correctly, but I am getting a lot of flickering on my screen. My view is mostly meshed polygons. ( using GeometryModel3D).

There are flat polygons sitting on top of each other ( 0.1 apart). But now the view is not drawing this correctly. It flickers a lot and the polygon mesh from behind is shown in front in places its like it can't work out the z levels even though the two shapes do not touch.

If is rotate the view and look at it from the reverse direction it draws correctly and the flickering disappears.

Do you have any idea why this might be happening? 

Please let me know if my explanation is not detailed enough 

regards

Murray