Normal Map mystery

# 1 05-09-2006 , 05:24 PM

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Join Date: May 2004

Location: Utah, USA

Posts: 369

I've been searching for info on normal maps. I've found a handful of tutorials and other reference material. I've seached through all of my Maya and Mental Ray books. I seached this board too. After all that searching and reading, the only information that made any sense at all to me was this.

"All those little wrinkles and stuff aren't really there. They're created by the normal map and the light source(s). A bump map would always show the same thing regardless of the light direction. Normal maps take light direction into account. Results are more realistic than regular bump maps."

Other information seems to be suggesting the same thing; a "high powered bump map"... yet other sources suggest that normal maps are only used in video games for realtime surface information.

I remember seeing a behind the scenes clip from The HULK that showed the CGI hulk's head with a normal map on it.

Can someone explain what all the mystery about normal maps is?

What is the actually purpose of a normal map and what is it's typical application?

How is it different from bump maps?

If it's so good, then why use bump maps?

I went to Vlad's site and I noticed that he uses normal maps and his models are fantastic but that doesn't explain why he used them. Vlad, if you're reading this, please shed some light on the subject. I'm not lazy but the truth is that I can't find any info on normal maps that doesn't dance around the subject. Help!!

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# 2 14-09-2006 , 10:15 AM

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normal maps render faster than bump maps. because for normal maps the slope of the normal texture are already calculated; bumpmaps needs to be analyzed at rendertime and calculate the slope.
thats why games use them most. they are realtime/pre calculated.

again like you posted, norma maps take into account lighting info. so it s more realistic than a bump, which is just flat, regadless of light direction.
and also the fact that you can bake a lot of surface info into a a normal map, u can bake something low rez look really great, or a medium rez look like its a high rez mesh, or just use it on a high rez for low frequency details that a displacement map would take too long to compute.

i stopped using bumps maps completely just because its faster and maya can render them without problems.
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# 3 14-09-2006 , 05:21 PM

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OK! That helps. I suppose the next step I should take would be to sit down and generate some normal maps. Since I do all of my medium and high frequency detailing in Zbrush, I will generate them from there. I can tell there is still much I don't understand about normal maps but I will keep digging. Please forgive me if I come back with questions that seem obvious but I really want to understand normal maps. If you could recommend a book or tutorial for clueless people such as myself I will really appreciate it. I have the steps for generating normal maps in Zbrush but I don't have any idea how to make one in Maya. Also, I assume that when you wrote that Maya can easily render Normal maps, you were including Mental ray in that statement.... yes?

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# 4 14-09-2006 , 07:01 PM

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Location: stuck in the 90's boston, USA

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here are some quick links.

https://www.jeffparrott.com/normalmaptut_02.html

great explanation and resource links here

https://www.bencloward.com/tutorials_normal_maps2.shtml

good luck.

i highly suggest zmapper if u extract normal maps in ZB.

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Last edited by vladimirjp; 14-09-2006 at 07:10 PM.

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