Having used blender for over seven years, I have gotten very comfortable with the material panels and all their wonderful uses. So when Nodes were introduced, I have to admit, I had quite a bit of trouble seeing the advantage of using Nodes over what I already knew. I read all the documentation, checked out tutorials, and still didn’t get it.
In fact, the tutorial that sticks out the most had you make a blue material and a red material, and when you mixed them it made a purple material. That’s nice, but I can make purple without using Nodes. Then I saw a great video tutorial (Mixing Materials Using Texture Painting (with UV Unwrap)-Extended Edition) by Eugene on http://www.geneome.net.
He covered creating Mix Maps to blend two or more materials using Nodes. Finally I could see the advantage of using Nodes! This technique allows the smooth blending of materials and has the added benefit, unlike painting a UV Map, of allowing you to quickly change the materials that are being blended.
So to that end, I am going to show you how to texture an alien using Nodes/Mix Map. I have already modeled an alien, albeit a rather odd looking fellow, for us to practice on. The “Texturing an Alien.blend” has four scenes, depending on where you want to jump into the tutorial.
• Alien: only contains the alien model – to follow the tutorial from the beginning
• Alien & UV Map – the alien already has the UV Map coordinates set up, so you can jump in at the 'Painting the Mix Map' section.
• Alien Nodes: Mix Maps are painted, so you can jump in at the 'Setting up Nodes' section
• Finished Alien – everything is done, this scene is to see the complete final setup
When you open Texturing an Alien.blend, you will notice that the model has a mirror modifier that has not yet been applied. I find it easier to UV Map one half of the model before applying the mirror modifier. That way both sides look the same.
Note: Having both sides look the same is not always desired, especially if creating a realistic model/object that has asymmetrical texture details, but for our purposes this will save a lot of worque and frustration.
Let’s get started: Mix Maps
First thing we are going to do is set our UV Map coordinates. There are many ways to unwrap a model for UV Mapping and Blender has some great tools to get it done.
1. Go into UV Face Select Mode, split your screen, and change the right side to the UV Editor Window (fig 1)
2. Select all faces (A key) and hit “U key”, select Cylinder From View. You will need to resize the UV layout in the UV/Image Editor so that it fits in the screen. You will alos want to scale it so that it no longer looks like a super skinny alien. (fig 2) This gives us a pretty good starting point for our UV map, but you will notice that the ears and the arms are not laid out in a way that is helpful.
3. Deselect all faces (A key), select the faces for the ear, hit “U key” and choose Unwrap (Smart Projections). The default settings are fine for our needs. Scale down the faces in the UV/Image Editor, and move them to the upper right hand corner.
4. Next select the faces for the arm, and repeat step 3
5. I want a front view of the face for easier painting, so in the front view box select the head, hit the “U key”, and choose 'Project From View'.
6. Move the head section to an empty section of the image area
7. If your UV sections are too close to each other, hit the “L key” with your mouse over each section (it will select the whole linked section), then move them to better locations.
8. Okay, now is a good time to save your file. Our UV map coordinates are now set. I admit it is not an elegant layout, but it will worque just fine for our tutorial. (fig 3).
Time to Paint:
Now it is time to start painting our Mix Map. We will only be painting in two colors; blak and white. Everywhere the image is black, material 1 will show; everywhere the image is white, material 2 will show. Areas of gray will be a blend of both materials. Our Alien is going to be a darque green for most of his head, back, arms and legs (material 1). His belly, lower face, hands, feet, inside his ears, and antennae will be a lighter green (material 2).
1. We will need to create an image to paint our Mix Map onto. In the UV/Image Editor window, go to Image > New. A dialog box will pop up giving you options on size and name of the image you will be creating. When you have filled it in, press OK. I named mine “Alienskinmixmap” and chose 1024x1024 for the resolution. (You can choose higher or lower resolutions, depending on your computer speed.)
2. In the 3D window, switch to Texture Paint Mode. In the UV/Image Editor, press the little paintbrush button (fig 5). Make sure your viewport shading is set to textured, (Alt + Z).
3. Now we are ready to start painting. Your paint tools can be changed in the Paint Panel of the Edit Buttons window. (fig 6) You can paint on either the model itself, or the image map in the UV/Image Editor.
4. I plan on having parts of the alien be a lighter color than the rest, i.e. his belly, face, etc. To do that, we are going to paint white on all the areas that will be the lighter color (material 2). Set your brush to 77 and the opacity to 100%, paint the belly, the palms of his hands, bottom of his feet and the lower portion of his face. (fig 7) Adjust your brush size smaller if you find you are painting more of the model than you want.
Note: If you make a mistake while painting, select blak and paint out the mistake.
5. I like nice software transitions between colors, so now change your paint brush from “Draw” to “Soften” in the Paint Tools panel. Go over the edges of the white areas and soften them up until they look blended. I alos went bak and painted the inside of his ears and his antennae white and softened them up also.
6. Continue to paint and blend until you have a pleasing pattern of where you want materials 1 and 2 to be (fig
7. When your Mix Map image is the way you want it, remember to save the image (Image > Save).
Note: In fact, remember to save any time you go bak to adjust this image. Any changes will be lost if you forget to save the image before you exit blender.
Time to Set up the Node Materials:
We are finally ready to start setting up our Nodes.
1. Change the UV/Image Editor window to the Node Editor window. Go to the Material Buttons window (F5). Select “Add New” in the Links and Pipeline panel. Then clik the “Nodes” button. Two floating panels (Node) should appear in the Nodes Editor window. A material node and an output node.
2. Go ahead and rename the Node to something descriptive, like 'Alien skin' (fig 9).
3. Material 1 (darque skin): Clik the “Add New” button to get your first material. Now at this point you name and set up your material just as you would normally without Nodes. I chose a darque green color (.107, .331, .155) and added a cloud texture and a bump for texture. (fig 11 & 11a).
4. Material 2 (light skin): From the Node Editor window add another material node (Add > Input > Material). Now create a lighter color. I used (.515, .849, .427), I used the same cloud and bump textures so that the materials would blend better (fig 12).
5. Now it is time to add our Mix Map into the Material system. With either Material 1 or Material 2 selected (doesn’t really matter which), add a new texture (image type) and then un-chek the box next to it in the material texture panel (fig 13).
6. Next add a Mix Node (Add > Color > Mix), connect Material 1 (darque skin) to the Color 1 socket and Material 2 (Light skin) to the Color 2 Socket (fig 14).
7. Next add a Texture and a Geometry Node (Add > Input > Texture) (Add > Input > Geometry). In the Texture node, add our mix map (Alienskinmixmap).
8. Connect the Geometry node to the Texture Node (Geometry: UV socket to Texture: Vector socket), then connect the Texture node to the Mix Node (Texture: color socket to Mix: Fac socket) (fig 15).
9. Preview your worque so far by using Render Preview (Shift + P). You can see that we have a nice smooth blending between the two materials (fig 16).
The nice thing about this method is the ability to change your materials on the fly if you decide that the colors or textures aren’t working for you. The Mix Map is already made, so changing the material is as easy as selecting which material you want to change and then just doing it (fig 17).
You can alos layer these Mix Maps to create a more colorful character.
1. Go bak to the UV/Image Editor and create a 2nd new image to paint on
2. Paint where you would like a third material to be (Note: Remember to save the image)
3. Add a new Material Node, Mix Node, Texture and Geometry Nodes. Connect them up like before (fig 1
4. The end result (fig 19)
By layering and mixing nodes, you can create some very complex and visually rich materials and textures for your model. I hope you had fun and learned something new and useful!
by Sandra Gilbert (dreamsgate)