Is it possible to make spheres and cylinders by painting a normal map?

malcolm · Nov 2010

I'm wondering if it's possible to create sphere or cylindrical shapes in a normal map from a greyscale image, or is it only possible to do this via a high to low bake or render of a normal map shader from a top down view and then composite these elements onto your normal map.

00Zero · Nov 2010

sure you can. unless youre talking 100% accurate then probably not.

Carl Brannstrom · Nov 2010

It's possible with layer effects in photoshop (bevel and emboss).
Check this out: http://www.paultosca.com/makingofvarga.html

(Part 4.4.2)

PogoP · Nov 2010

Or you could use nDo if you're talking about what I think you're talking about!

malcolm · Nov 2010

I'm using nDo but can't get it working. My sphere always goes flat on top.

Eric Chadwick · Nov 2010

It's really hard to do correctly. I used to work with a programmer that really wanted displacement maps instead of normal maps, so he could convert them into normals himself.

The gradient for a dome has to be biased/weighted in just the right way to get that nice spherical curvature when it's converted into a normal map. That kind of weighting is pretty hard to do. And you need more than the standard 8bit range (16bit works OK) otherwise you get stairstepping and/or noise in the normal map.

Bevel/emboss can do it, but the curve controls in the layer style have to be tweaked carefully, and even then it only really works for smaller shapes. In my experience anyhow.

Modeling is soooo much faster. Besides, you can bake one set of doodads, then copy/paste/resize them a bunch of times. For example...
http://wiki.polycount.com/NormalMap#Pre-Created_Templates

malcolm · Nov 2010

Thanks Eric, I came to that same conclusion today after much trial and error.

Eric Chadwick · Nov 2010

Heh, sometimes that's the best way to do it.

Is it possible to make spheres and cylinders by painting a normal map?

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