OOPs and Bump Mapping

Hey there,

I was hoping you could help me out on some incredibly simple questions. They aren’t obvious to me, so please be gentle.

In the OOPs schematic… pretend I have a material, and that material is connected to a cube. Then my new geometry, say a sphere is introduced… how can I unlink the material from the cube, and then link it to the sphere? I’ve tried to disconnect/connect the plugs in the OOPs, and it won’t let me.

In regards to bump mapping, I’ve found this tutorial:


The reason he’s (the guy who wrote this tutorial) creating these shaded areas of color on the monkey is to create an alpha channel, this seems like a overkill to do. Couldn’t I just export an orthographic render, bring it into Pshop, and run a levels on it for the same effect? Lastly, once the bump map is applied, how can I move it, scale it on my material from a more visual guide… I understand I can manually tweak the XYZ UV settings, but I was hoping for more of a visual approach.


Some info on the Outliner if its any help


Isn’t he making a normal map, not an alpha channel?



I assumed he was making an alpha-type image to apply as a bump map. And throughout that tut the final was a rendered image that was then utilized as a bump. I’m not entirely sure, I’m a little confused. I followed the tut but the whole time I wondered if I could have just rendered a basic image, and then pshop’d the image to a grayscale map… seemingly because the rendered image i created via the tutorial was used to act as that (from my point of view at least).

First of all, that tutorial is from way back in 2005 - Blender can now bake normal maps, which is a far, far better way of doing them in any way imaginable.

First, some distinctions - there’s a difference between a bump map and a normal map. Both are used to create the illusion that there is geometry when there is none. Both of them have a benefit over regular images in that they’re dynamic. If the light comes from the right, the right side of the monkey will light up and if it comes from the left, the left side of the monkey will light up (as you’d expect with actual geometry). A static image is bound to the same lighting, always, of course.

Now, a bump map is a greyscale image where any brighter colour means sticking out and a darker colours means denting in. A normal map is a colour image, which usually has a distinctive blue colour (if it’s a tangent space one anyway, which it is in thise case and in most cases). In a normal map, every pixel is a direction, so that the renderer can see how light should bounce. An alpha map is something different altogether, which has to do with transparency, which isn’t at all discussed in the tutorial.

Here is more detailing on how normal maps are made anno 2009.
This is a guide I wrote on normal maps with some theoretical info. It’s not the best out there, but it’s the only one I have bookmarked :wink: .

Thanks Zwebbie!

I’ll take a look at those links when I have a spare moment.

I didn’t know a normal map was different from a bump. So a bump map utilizes an alpha and a normal does not… I think I got that right. So do bumps and normal maps do about the same thing primarily? It sounds like a normal map is a bump map on steroids.

I’ll definitely read more into your links and probably answer these questions myself, but don’t let that deter you into answer these =).

Yeah, it’s hard to find tuts that are relevant, as they are either dated or use 2.5 (which isn’t out yet, weird!)

Thanks! :cool::cool::cool: