View Full Version : Normal Map Extraction from two different models...

09 September 2004, 03:27 PM
Hi, I was wondering if there was a way to extract normal maps from a lowpoly model created in another program from a high poly model (also created from another program) that was Zbrushed. From my understanding (I could be completely wrong), Zbrush generates its normal and displacement maps from the same one model and uses the difference between subdivision level 1 and the highest subdivision level. However, I want to use two completely different models. Is this possible? Thanks.

-I tried searching the forum, but didn't come up with anything.

09 September 2004, 05:29 PM
I'm pretty sure this isn't possible.

You might want to do a search on the forums...

But again, doubt highly that there is any way that this could work.

09 September 2004, 05:39 PM
This can't be done inside of Zbrush. You could use ATI's normal mapper utility to do it oustside of Zbrush though. Although I have had zero success with it myself. And I think XSI, Maya, and perhaps 3ds Max (with the kaldera plugin) can make normal maps within them.

09 September 2004, 12:29 AM
Oh well, I guess I will have to use ATI's plugin. Would be so much easier to be able to do it in Zbrush with 2 models since importing a 500k - 1Million poly model back into XSI or Max is such a pain as they are not as capable of handling such high poly counts as Zbrush is (well alteast on my machine). Anyways, thanks for the info.

09 September 2004, 12:34 AM
your best bet is to use a program called melody from nvidia.. that allows you to load in two different models and will create a displacement map and or normal map from the difference. you can export an obj from zbrush and load that directly into the program.. i've had success with objs in excess of 2 million polygons.. so i know it works. unfortunetly you just can't view the obj when its that high in melody.. unless you have a crazy computer..but it works without showing the high version either way.. zbrush cannot do what you need. and maya always crashes while trying to import obj's in the millions.. i haven't had too much success with the displacement maps being spit out of melody though.. but normal maps are fine.. good luck!

09 September 2004, 01:44 AM
I should have mentioned melody too. I think you need an Nvidia card with that though, since I can't even get it to run on my PC system.

09 September 2004, 02:09 AM
Ah, Melody does sound like best fit since you dont have to go through a 3d package and export your model from there. I will give it a shot..although I do have an ATI card so I hope it still works. :scream:

09 September 2004, 03:28 AM
it works.. dont worry.. i'm running a 9800 pro and it works fine! :)

09 September 2004, 08:51 PM
I have not liked the results I have recieved out of melody. I really wanted it to work, the interface is nice but the normal map it outputs is low quality. The colors are odd, there isn't many choices for anti aliasing. I also had a terrible time with seams being created. I would recommend ATI.

09 September 2004, 11:47 PM
I tried Melody today, but for some reason I couldn't see the models I was loading. I could tell they were loading because it took a while on the high poly, but neither the lowpoly or the high would display in the window. Very strange. I will go through the pdf file again and see if I overlooked anything, but so far no luck becuase when I hit button to create a normal map it crashed on me. :sad: I have used both XSi and the stand alone ATI program and have gotten good results, but I really would like to get Melody to work for ease of use by not having to import a high poly model back into XSI. I'll give it another shot.

01 January 2005, 11:23 PM
Melody is crashing on me like mad. i can load the first model in fine but when i load the reference model it crashes. when i try to export a 3ds from max (the hi res) it bitches about it being too high poly or something like that, and the obj will export, but all crash on import, i even tried a test with a not so high poly model.. like what, 30k?? and it still crashed. I'm having so much bad luck with doing ANY normal mapping at all (i'm trying EVERYTHING) that i'm starting to think its my video card or something. i have a radeon 9700 (supports 2.0 shaders) and so things should work out fine, but so far NOTHING has worked for me.

Jonny Bubonic
02 February 2005, 06:13 PM
In the manual for Melody, it mentions that 3ds format has a much lower poly limit (although I believe it said 64k, higher than yours). If you can get your model into .obj format you might have more success. I've found the normal maps made in Melody to be very good quality, with very few, if any, artifacts or seams. I've use a 750k reference model without problems.

02 February 2005, 10:23 PM
You could do it I think if the objects share the same UVset. But this would actually requires you to start from the beginning. You would make the first objecy in Zbrush, map it in Zbrush or Maya, export it then make your second object by altering your first mesh. Then export the second mesh to maya and do a blendshape between the two. Because they have the smae number of polygons, the blendshape would work but might prduce unexpected results. Since they also share the same UV, you can apply the normal map to both.

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