avi as screen environment in max

[flipside]

Hi,

Any idea why an avi file set as environment map in max (screen) will not render animated? It always renders frame 1 in the background. I even can't get it to animate in the viewport background (I ticked 'animated background' in the viewport background properties).

Also, if you have an object on top of a matte plane, how can you render the shadows, caustics and GI shadows with correct alpha channel so that it can be composited over the background later? When I tick the affect alpha option in the matte properties, it only takes into account the raytraced shadows and part of the shadow pixels contain the background image. So if you for example choose another background in the video editor you will still see the old background partially in the shadows.

Or is the only way to do this to render every single element seperately (so no alpha channel on the shadow) and then blend them together with the correct blending modes?

[vlado]

If you want to be able to replace the back-ground in post, then you will need to render your scene against a black background, and then do the compositing with whatever particular background you need.

For the .avi file, I have no immediate idea; a sequence of .png files works fine though. Does the .avi work with the scanline renderer?

Best regards,
Vlado

[flipside]

hey vlado, no idea about scanline, too busy here but I tried png and indeed works fine now. The avi worked 'sometimes'. I didn't realize I could use a sequence which is in fact easier