I am creating some objects, like cylinders, cones, and planes, where I want to color individual faces. When I try to do that for these mesh objects, it colors the entire object instead of just the face I selected. Can someone help me understand how to do this?
I should let you know, I am new to Blender and am running version 5.1.2.
Hi there,
You can do this easily in edit mode. Start by creating multiple materials and multiple material slots
Once you have two or more materials that you are happy with, enter edit mode by pressing tab, then enter face select by pressing 3 on your keyboard.
Start by selecting the faces you want the first material, then go over to the materials editor and press assign.
You can repeat this for multiple materials and faces.
You can then enter material preview by pressing Z then 2 to get a live preview.
Here is a quick screen recording I did:
Yes, that works fine for a cube but it does now work for a cylinder, cone, or other objects shapes. I also would like to be able to apply loop cuts to something like a cone and color faces in the cone or extrude the face of a cylinder and scale the extrusion, add a loop cuts to something to the extedne and scaled part and then add some additional colors to the results.
As a silly example: I am going to draw a pencil and the “sharpened” end needs to come to a point. Part of the point will be brown (for the “sharpened” portion, and the there will be the part for the lead which will be black. I have not been able to control the coloring on the “sharpened” and lead parts correctly.
As I said, I am new to Blender so this is part of my learning process.
Are you in face or edge selection mode?
If you are selecting only the vertical edges of the cone or cylinder, you wouldn’t be able to assign the material because the face isn’t actually selected. You have to either switch to face selection or select all the sides of the faces for them to be really selected.
In edge selection, the face itself is selected only if all its sides are.
You should be able to control the colours of individual faces the same way for a more complex object that you would with a simpler one.
The only thing to make sure is that you are in fave select mode.
It would be useful if you could share a screenshot of the issue you are having.
Applying multiple materials might be a good way to do it but you can also use a UV-mapped texture. It might be more work but, depending on what you’re going for, you might have a better result.
UV-unwrap the object. Go to the UV Editor. Make sure your UV layout is the way you want it. i.e. all your verts and edges are “plum, level and square” so to speak. Once you have your UV layout the way you want it, export the image as a PNG.
Now, open that PNG of your UV-layout in GIMP, Photoshop, et. al. Make your UV a separate layer. Put another layer over top then paint on that layer (or whatever graphics techniques you want to use) and make sure that your art matches up with the UVs on the bottom layer.
When you are done, before you export, turn off, hide or disable the UV-map layer. Export JUST the imagery you made. Look at the finishing touches and, when you’re satisfied, apply that image as a UV-texture to the original object.
If you’ve done your job well, the colors and textures of the image you made will line up with the verts, edges and faces of your original object.
Bonus: If your object is animated, by shape keys, armatures or other things, as long as the faces move in a predictable manner, Blender will be able to keep everything lined up. Just be aware that if your animation warps the object in an extreme manner your UV-layout might not stay lined up the way you expect.
OK Guys, thanks for your replies. Here is a model that I am going to attach for you to try to review and let me know what the heck I am doing wrong.
As you will notice, I have the Face selected. I did that in when trying to assign the color to a face in each of the object. As you will notice, it worked fine with the cube, but the other 3 objects (with green arrows) it assigned the color to the entire object even though I had the face selected.
Understand what you are trying to say but I am trying to understand why the “simple” approach is not working/what I am trying to do.
You need to first add a second material to the object (step 1 in the picture), then pick the material containing the other color you want to use for this newly-created slot (steps 2 and 3), then finally assign this second slot to the selected face (step 4). You can do the same steps for additional colors, just make sure you’re in edit mode (like you are in the screenshot), make sure the newly-created slot is selected in the panel under that “1” arrow from my picture, and make sure the faces you intend a new color are the ones currently selected before you click the button “Assign”.
Edited for better wording and additional, important details.
Each object has its own separate list of materials. In your scene, only the cube has a list with multiple materials, that’s why you can’t assign them to the other objects.
If you want multiple materials on a second object, you have to create material slots on that new object too and assign materials to those slots like @dsilverz explained.
OK, you guys have solved the problem for me. Clicking the + turned out to be the real key and now I understand be issue about each object having it own set of materials. Since I kind of kney ahead of time the colors I wanted to use. I went off and created a set of materials and then using the + and then going to the list of materials in the model, I was able to successfully assign the wanted material to the portion of the object I wanted to color.
For me, understanding this is a big step forward. 
