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MattBirkett-Smith
03-15-2007, 05:34 PM
I was just wondering if anyone with experience in generating normal maps from within mudbox could answer a quick question.

Normally I use Maya's surface sampler to generate normal maps but if I try and use it on meshes above 500,000 or so it gets pretty flaky. Zbrush is very good for generating normal maps but is only any use if your level one base mesh happens to be exactly you want for topology in UVs which for my current workflow it probably won't be.

I was wondering whether Mudbox allows normal map creation from completely different meshes and also what sort of poly limit I'd be looking at without crashing.

JamesMK
03-15-2007, 05:50 PM
I was wondering whether Mudbox allows normal map creation from completely different meshes

Yes, no problem. You can load any lowpoly object and extract a normal map based on any arbitrary highpoly object - they do not need to be related in any way (aside from the obvious rough matching of volumes)

and also what sort of poly limit I'd be looking at without crashing.

Should be very high. Personally I've used high-res objects around the 5 million mark, further smoothed during extraction (so in theory that would be something like 20 million) for 2048x2048 maps without any problems on a system with only 1 GB of RAM. I know for a fact that others have gone way past those numbers too.

MattBirkett-Smith
03-15-2007, 06:08 PM
Excellent, just the kind of answers I wanted to hear :).

As a random aside and total longshot I don't suppose you know of any reasonably sane workflows for transferring occlusion as well? ;)

edit: I've heard Turtle could probably do this but I don't have access to it

dpizzle
03-19-2007, 12:27 AM
what should the normal map bake setting look like in mudbox?
the reason i'm asking is because whenever i go to export a map out, i get an error.

i open up the lowres .obj file (not mudbox file) and use it for the lowres source for the normal map.

use the highres .obj file (not mudbox file) as the source for the normal map (load from file in the map extraction window)

i set the map to export to my desktop as a .tif (or jpg or png - any suggestions on this?)
@ 1024x1024

whenever i 'start operation' the operation window opens, and it runs through 2 stages, and then after the 2nd is finished, it give me the 'an unknown error has occured' error.

and no map at all is on my desktop.

any idea why this is happening?

any help would be great! pleeeease! :thumbsup:

JamesMK
03-19-2007, 10:20 AM
Matt - nah....

dpizzle, this could be due to one of two problems: the UVs on the lowpoly, or the "monolithicity" of the highpoly -

UV checklist:

- No overlapping UV faces
- No UV faces crossing the border between adjacent UV tiles
- No UV points precisely on tile border (leave a thin frame all the way around each tile)

Highpoly checklist:

- Make sure the highpoly object is properly combined to form ONE SINGLE OBJECT. You can check this by importing the highpoly the standard way first - if it shows up as several different objects in MB's object list, it's not properly combined.

As far as map file format, TIF is indeed the best choice.



.

dpizzle
03-20-2007, 02:43 AM
james,

thank you so much for the info - i'm gonna get on that asap and let you know how that worked out

:thumbsup:

thanks again
p.s. your 'making local weather' image is amazing, the guys at work love it as well.

dpizzle
03-20-2007, 03:05 AM
what should the normal map bake setting look like in mudbox?
i'm getting some weird results inmy map export
the reason they are laid out like this is for a test, of course. I wasn't sure how to go about using the same map on both sides of the mesh so i just laid it out 2x and it seemed to work ok...except for the few little didlies around some of he edges..

http://www.davidpayneonline.com/misc/Dominance/NMTEST.jpg

and, as i asked before -
how would i go about only using half of a mesh to create a normal map that will be mirrored over? can i use a half of a low poly mesh with the full high poly mesh when generating the map from mudbox??

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