3DStudioMax padding problem

capone

Trying to create a lightmap with render to texture, tried adjusting padding amount from 2 to 12 but it makes no difference at all. I could paint out the errors but I want to know what the problem is and potential solutions?



Anyone? thanks

Valandar

It's possibly not padding, if the geometry is intersecting. Were you rendering with scanline or MR?

00Zero

well, its working on some bits but not others...

is it all a unique unwrap or are you overlapping some parts that are the same shape?
(thats ok to do as long as you bake with just 1 pieces and then overlap them AFTER).

but your problem might be that youre overlapping the uvs of the pieces on the left to the pieces on the right (or vice versa) but the spacing of the vertical column meshes isnt perfect.

basically, it just looks like you have to go into the unwrap and make sure all your islands are exactly on top of each other (if youre overlapping) and that the actual distance between the vertical columns is equal.

marks

I've had problems similar to this for pretty much every AO bake using the Scanline renderer in max, since I started using Max. Also gives a blue hue to the AO bake which it looks like you also have. Desaturate and see the difference. I just figured this was how Scanline did it, I've been fixing the bake errors by hand for a number of years

Valandar

Marks: That's probably because Skylights load in with a very faint blue tint; change the color of the light to white and it's gone.

Another thing is intersecting geometry will not render quite right UNLESS... unless the material applied is solid white, AND has 2-sided checked. Then any intersecion between "watertight" meshes will be solid black instead of solid white.

capone

Thanks for the suggestions. Fixed it with Valandar's tip about applying a white material with 2sided enabled. As you can see in the image I'm not sure if it's the perfect solution...

1) Some occlusion is darker then others (the beams on both sides have darker occlusion than that of the middle beam)

2) If you look closely on the very outer edges of the beams they have a faint dark line

of course, these are hardly noticeable once you apply the diffuse map etc but would be interested to know of a better solution. I am indeed using scanline. As for the overlapping UV's I do have these in some places (it has it's own unique mapping for lightmap). For example the left and right beams share the same mapping and the middle bean has it's own unique mapping. As 00zero mentioned I need to identify the overlapping parts and place the extra pieces outside the area then overlay them later.

I'd still also be interested to know why upping the padding in RenderToTexture doesn't make a difference to the entire render.

Xenobond

The padding value affects the file saved in your output path. The padding will not be visible in the render preview.

Valandar

Because padding only applies to the edges of the UV Template. There's still geometry under those overlapping sections, so the padding doesn't affect it.

Scanline AO also has a much sharper curve than AO rendering with MR. If you MUST use Scanline AO, then I'd suggest rendering it at a MUCH higher resolution, then scaling it down in Photoshop or your image editor of choice.

capone

So generally people make lightmaps using mental ray as opposed to default scanline?

Eric Chadwick

A nice review of different AO methods in Max.
http://www.laurenscorijn.com/articles/ambient-occlusion-baking