View Full Version : makes me mad - prob with wrinkle render using normal map

11 November 2005, 01:54 PM
Hi all i recently modeled a low poly head in xsi5, then imported into zbrush2 and did a high poly one, applied as a normal map back in xsi, but the result is quite bizarre. I painted some wrinkles in zbrush, but when i did a render inside xsi5 the wrinkles arent as 'sharp' as it looks in zbrush... what's more, wrinkles seem to be popping outward of the skin, rather than inward direction... it really drives me mad!!!

The normal map i used was tangent normal map.

img1 is the zbrush model
img2 is the xsi render
img3 is the normal map

notice that weird wrinkle (and many others)...

p.s. also in img3 (the normal map one) notice there is something really strange inside the eye region

11 November 2005, 03:38 PM
What was the process that you used in creating/exporting the normal map (in zbrush)?

From my personal experience, I think that soft create a better normal map.

11 November 2005, 05:52 PM
i did the normal map in zbrush 2 with tangent + adaptive + smooth UV turned on. (i also tried other combinations, but the results are the same)

using xsi to create normal map... are you talking about 'ultimapper'? i tried it, but the zbrush modified model is too heavy for importing for my machine...

thanks for your reply :)

p.s. i think the problem i have come across could be a common prob... i remember one of my friend has told me the same prob before, but he never solved it as well.

11 November 2005, 06:12 PM
hmmm I really wish that I could help but I'm stump on this. Which shaders are you using in Soft?

11 November 2005, 10:24 AM
Hi carnavor, i appreciate your help here!

i was doing some test thesedays, i used a friend's machine to generate normal map inside xsi 5 with ultimapper, now the wrinkle area looks much 'sharper'... (btw, the xsi 5's gigapoly core is so powerful! there's no prob importing 2 million polygon model from zbrush!)

however the prob with the wrinkle's 'inward' and 'outward' prob remains. i had a careful look at the model inside zbrush, and guess it could be my zbrush model's own problem...

11 November 2005, 12:23 PM

It seems your normal map is perfect. The problem seems to be with XSI when it's applying the normal map on your model. Sure it's inverted, just it.

Try invert the normal map when you apply it into your model.

I'm not a XSI user. I play sometimes with 3dsmax and you can invert the effect of the normal map. I'm quite sure XSI can do that too.

If not, try inverting the normal map in photoshop.

See ya!

11 November 2005, 07:42 AM
Hi ctl3d32, i did try inverting the map as u said, the results is wrong as well.

1 is original render; 2 is with normal map applied on; 3 is with inverted normal map on.

11 November 2005, 07:55 AM
4 is my zbrush model, i adjust the light in zbrush, put it on the same position as in xsi... however the wrinkle in zbrush is just looking better

5 is the rendertree in xsi

11 November 2005, 11:53 PM

I will tell you what i do to create and apply normal maps into 3dsmax. Maybe you can take something useful from it.

1. Make my base model in 3dsmax, create a unwrap UVW and export it as an OBJ (including texture coordinates, smooth...);

2. Import my base model into Zbrush and detail it;

3. Let's say i created 4 subdivisions in zbrush when detailing the base model, and i want my subdivision number 2 to be my new base model (i do this because i want my base model a little more detailed). I export subdivision 2 in OBJ format, so that i can open it in 3dsmax later;

4. Still in subdivision 2, go to TOOL menu -> NormalMap. Select Tangent, Adaptive and set a desired resolution ( 1024 or above for more detail). Click button <Create NormalMap>;

5. Now that my NormalMap is created, go to TEXTURE menu. Your normal map might be there, near the Export button. Scrolling down, you face some buttons: Flip H, Flip V, Rotate, Invers. These buttons are precious, see below why;

In 3dsmax, i had problems applying the normal map because it was Flipped in V direction. Before i click Export button in zbrush, to export my normal map, i had to click the Flip V button first in zbrush, later the Export button. I exported it in TIFF format.

(it seems that in XSI, you normal map is inverted. Click Invers button before exporting it into XSI).

6. Now that i have my normal map correctly exported, i import my new base model (step 3) into 3dsmax, create an Unwrap UVW (Should be the same kind of Unwrap UVW created in Step 1), sometimes i apply a little meshsmooth (level 1) modifier on top of all, and apply my normal map into it.

That's it.

See yah!!!

11 November 2005, 09:53 PM
You just need to invert one of the color channels in your native app

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