3DS Max - Render to texture results in black screen when saved to file

Violet

This is a long standing problem I've had, we had it in work and now I have it at home. We could never figure out how to fix it, so went back to 'default scanline renderer' AO texture bakes, which isn't very good - we ended up using Maya. A few minutes with Maya - it's done!

The scene renders fine visually, but when it comes to saving the file, it is always black. It's using Mental Ray.

We messed around with all the settings, and even had a single PC to do AO renders, and never got it fixed - it's not file format, compression, 16/32 bit settings - I believe we tried changing every setting. The render is visible, but the saved file is black when it is saved as a 'Complete Map' and a black and white image when it's saved as 'MR Ambient Occlusion'. Saving to TGA, BMP, EXR, etc has the same effect - it's just saving a blank image in 'CompleteMap'. Saving as 'MRAmbient Occlusion' is visually useless.

It's easy to save the file out, but the rendered image on screen doesn't apply padding, so you're left with a black line when you put it on your texture.

Did anyone ever figure this out? It's going back as far as Max 2011.

Eric Chadwick

I think this is solved by changing the Object Properties of the lowpoly mesh to be not visible to the camera. Because when baking with Mentalray in 3ds Max, it renders both meshes for some dumb reason.

It could also be this:
http://wiki.polycount.com/wiki/Texture_Baking#High_Poly_Materials

Violet

I'm not trying to bake from hi poly to lo poly, it's just to get a nice AO treatment for the texture - will try the things you've listed. Back onto it now and I just can't figure out how to get the blasted AO out into a TGA.

If you reset and have a standard scene with the renderer set to mental ray (standard scanline is just not usable in terms of quality and speed), render out a single unmodified box with no material using a mental ray light (any) it comes out black. The only light that works is the standard 'Skylight', which is no good.

You can't render a texture using Mental Ray lighting using Mental Ray renderer, only standard none Max lighting. Go figure.

Either way, mental ray AO texture bake (regardless of what is on the render screen) saves out a black image, or artifacts of some completely undesirable render.

Eric Chadwick

Hmm, not sure what your trouble is. A box works for me, though it puts out a white TGA of course. Here's a teapot with an Unwrap and a Flatten with default settings. This is 3ds Max 2015.

Violet

Could you send that scene to me? I don't know what's going wrong here ...
Thanks
davidnibi@gmail.com

first image is the saved file, second is what you see in the viewport once it's rendered. I think I've tried everything, file formats, compression, alpha settings, 8/16/32 bit, etc etc etc

Eric Chadwick

Here you go
http://ericchadwick.com/examples/files/teapot_mr_ao_max2015.zip