Simple question (but I'm a newbie) and need help ASAP!

Hello Blender artists!
I’m new to Blender and using it for 3D rendering of the human brain for a scientific publication (to be submitted on Thursday!!!)

I have 56 separate meshes (generated from separate sections of the human brain, which all fit together to form the whole brain).

I need to color each mesh (separate brain sections) a different color (this I know how to do… at least one-by-one as I load the meshes).

Now here are my problems…

#1 I need to specify precise colors ON A GRADIENT for my 56 meshes… I want the first mesh to be light gray, and the last mesh to be dark blue, and I want all meshes in between to transition in a evenly manner from light gray to dark blue. I know I need to specify exact RGB values, but it’s more complicated then using evenly spaced values from one slider alone, because all three color parameters (R,G, and B) and needed to create these colors.

#2 I would like to be able to view a list of all the meshes I have, and to go down that list and color my separate meshes, one by one. It’s difficult to find the meshes once I’ve loaded them, because they all interlock in 3D space (the brain is complicated, after all!) So far, I’ve only been able to select colors for meshes as I load each mesh in turn, using the materials buttons.

#3 I would like to render the whole brain looking from the side (which I can do), but I would also like to render the brain, cut in half down the middle (so that the different sections down the middle of the half brain are exposed). I can do this by moving the camera inside the brain, but then everything is too close up. Is there a way I can make half the brain transparent or another technique so that the other half can be seen?

#4 Finally, I’ve been told that radiosity rendering is the way to go for a natural effect. How specifically do I accomplish this (remember, I’m one step below amateur!)… something about using an icosphere with its vertices as an emitter as in the skydome example??? Or something else maybe???

I would much appreciate help on any of these problems.

#1 - Try using HSV (Hue, Saturation, Value) instead of RGB to set your material colors. It’s a button on the Material Tab, under the color swatches.

#2 - For a list of objects in the scene, use the Outliner window. You can split your 3D view, and change the new window to the Outliner. It won’t allow changing properties, but does make selection of objects in complicated scenes easier.

#3 - One option is to use camera clipping . . . increase the Clipping Start in the Editing buttons for the camera. But keep in mind that the objects will appear hollow, as Blender does not have volumetric rendering. Booleans are another possibility (I haven’t worked with them much, and you may have to use a script to get the best results with complex meshes).

#4 - Rendering methods depend on the exact look you’re going for. You mentioned ‘natural’, but that’s a little general. If you can post samples of other images with the look you want, maybe someone will know how to replicate it in Blender, or other external renderers.

Hope that helps!