As you might know, there we are using Blender’s new render engine Cycles for ManICan. Since all of this is so new I think it’s better if we start from the basics. So for starters here’s what I know about correctly setting up bump maps. I’ll assume you have a basic knowledge of Blender and the Cycles render engine. Also, this Cycles allows to setup basic materials using a property interface, however I’ll be using only the node tree for clarity
First step is to create an Image Texture node and connect it to the displacement socket in your material output. This will inmediatly show some result acording to the image and the mapping coordinate you pick. In my case I’m using UVs
A word about Gamma:
Your monitor does not display colors how they really are stored in the image files. It actually distorts the image’s gamma with a curve. It is important to input images in the correct gamma mode to cycles. For example an image you use for coloring your model would probably be brought in as sRGB space, which means you want Cycles to render it just as you see it in your monitor, distortion and all. Why? because you created it that way, if the image looks good to you in your monitor you want to keep that result. How ever in the case of a bump map cycles should import the image just as it is in the file, ignoring all the correction workflow designed to compensate for your monitor. Confusing? lets get back to this in a later post, I’m really oversimplifying here 🙂
So anyway, in practice changing the color space is really easy. Open the N panel, set the image to Linear and see how the resulting bump effect changes!
I noticed a little glitch in the circles caused by the automatic subdivision of the UVs by the SubSurf modifier. Let’s turn that off
Now, as you can see, the Displacement socket of the output node is colored gray, this means it should receive Value lines. It’s a good idea to listen to that and convert our Color line (Yellow) to Value with a convertor node. This can prevent problems in more complex shaders (mixed closures). Just drag and drop a new RGB to BW node into the existing line and it will connect itself in between!
Controlling the strength of the bump effect is as easy as multiplying that value to the amount you want, let’s reduce it to only 10%
Much better. A Final touch can be grouping this bump map’s “treatment” nodes since we’ll likely be using them a lot all over the scene. This way reusing the same setup over and over becomes really easy!
Edit: someone asked how to tile textures in cycles! It’s very simple, just add a Mapping node and set scale higher than 1