Procedural Bumps

Does anyone know technically why the bump maps made with procedural textures don´t look as good as the exact same material baked and applied as a bump map bitmap??

Procedurals don´t have a 3D feel if you know what I mean, they look flat compared with bitmap bumping, and it is not a matter of adjusting the ´´nor´´ value, thay just don´t look the same.

If I bake a procedural texture as a Normal map, I get almost the same effect when using the baked map vs the original procedural texture. The Normal map is softer, but this can be changed with the filter value.

Are you baking the actual color texture map and then using it as a Bump map?

Can you show us the Map that you baked?

I don´t have it with me right now, but I just assign the material to color instead of normal and bake it. What I´m saying is that the baked material is ´´bumper´´ than the procedural one, it looks better. For some reason it has more depth.

If I wanted to achieve the same result with the original procedural, I would have to increase the ´´nor´´ value, but at some point the bump would start to look dirty, you know, the shadows would become too dark, and still it would be flatter than the bitmap image…

Wow…I’ve done a few test and I’m clueless…I must be doing something really wrong in here with the procedural bump map…

Please take a look at this file

www.jpbouza.com.ar/downloads/bump.blend

There you will find a simple sphere and two textures applied to it. One is the procedural bump, which actually does not bump at all!! It does some kind of bump faking, but not actual bumping.
Secondly, you’ll find a bitmap texture which was baked out of the previously mentioned procedural texture. Well, this bitmap texture bumps perfectly…

I really don’t know what I am doing wrong, hehe, PLEASE HELP!!!

Well you have got me there. I don’t know why the stucci texture is acting all weird. If I remember correctly the procedural textures basically have normal maps behind them. It seems when you add the color ramp to the stucci texture the normal map is getting all kinds of confused. It appears to show two distinct patterns overlaid. However, when you baked the Black and White texture, you are getting what becomes a very crisp bump map with only one pattern. Hopefully someone else will download your blend and have some more insight for you.

You can get fairly high quality bumps if you use nodes to achieve a bumpmapping effect.

You can set the nabla to 1 and set the size to 1000 in the mapping node. You need to input the normal value of the texture node then… the node setup can be found in the pynode thread.

Thanks guys. I find this issue in all procedurals, I used stucci just as an example.

I’ll check the pynode thread and see if I find a nice solution for this!!

Hehe, Where’s the pynode thread??

It’s a bug/feature.

The way the derivative is taken is rather hacky and while it works passably much of the time it isn’t correct.

I had hoped that once tanget-space normal maps were added for image textures the same code would be used for procedural bumps but that hasn’t happened.
https://projects.blender.org/tracker/?func=detail&aid=4437&group_id=9&atid=264
https://projects.blender.org/tracker/download.php/9/264/4437/2245/bump_yz_bug.jpg

Thanks Surt!! Well, I´m glad to know I´m not crazy!!!

Maybe I´ll report this again in the bug tracker, just to bring this issue back to light again!

Does anyone know where the pynode thread mentioned by Cyborg Dragon is?

I think it is a thread in the python forum here on BA.