3D objects don’t look like real world objects because they lack colour, depth and texture. But there are ways you can digitally paint your 3D objects in Blender 3D to make them look like the real thing.
In this article we show you how to texturize objects that you make in Blender 3D using photographic bitmaps and graphics you create. If you don’t already have Blender 3D, get your free copy at http://www.blender.org and follow along. It’s available for a variety of platforms.
Painting with Pixels
Modeling objects in Blender 3D is only a third of the picture. First you need objects, then you need textures on the surfaces of those objects, and finally you need lighting. We’ve already covered the first step, and the last step we’ll cover in a later article. Let’s talk about bitmaps.
Bitmaps are old computer speak for graphic image files, the kind you get from Photoshop or Gimp made up of pixels, as opposed to the kind you get from Illustrator or Inkscape which are CAD-type graphics. Files from the latter programs are not a picture; they are a list of instructions for how to draw a picture.
So we need to concern ourselves only with bitmap images, such as JPG, PNG or GIF files. What kind of graphics can you use for object textures? Well if you are an artist you can draw them from scratch. But the majority of usages just use artfully edited photos of real world textures.
A lot of CG you see in movies and TV is not ultra detailed 3D models, but quite simple models with realistic bitmaps covering them. They are like a car covered in photographic vinyls.
If you haven’t already added an object, for simplicity’s sake, add a sphere. Use “Shift + A” to open the floating menu and “Add -> Mesh -> UV Sphere.” Click the Modifiers button on the Properties menu (the little Spanner). Add modifier, choose Subdivision surfaces and turn the Subdivision Surface up to 3 on View and 6 on Render.
Change the view to camera by pressing 0 on the keypad.
To add a texture to an object, place the mouse cursor in the bottom left-hand corner of the interface till the cursor turns to a cross. Now drag till you have opened another viewport.
In the left viewport, select Node editor from the View menu. This is where the attributes of the texture will be set by adding nodes.
If you want to see the changes you make to the texture in real time (and your computer is fast enough), you can set the view to Rendered in the right hand viewport. Click the Viewport Shading menu (the little ball) and choose Rendered. This will show the textures on the objects in the viewport, so you will know when you have it right.
Note: if you haven’t set it already, choose Cycles Render from the drop-down at the top of the screen. This is a much higher quality rendering engine which we’ll be talking about in a subsequent article when we talk about rendering.
Right-click on the object you created to select it. On the row of buttons in the Properties editor, select the Material button.
Click the New button on the default material to assign a basic texture to the object. The default surface type is Diffuse BSDF.
In the Node editor a couple of nodes will now appear by default: the Diffuse BSDF node and the Object Output node. This is what we will use to form the basis of our texture.
Use the Add menu down the bottom of the interface to “Add -> Texture -> Image Texture.” The node will be stuck to the cursor until you left-click somewhere in the Node view.
Click the Open button and add a graphic, a pattern of some kind is best. Change the projection type by clicking on Flat and selecting Sphere from the popup menu.
Click the output “noodle” on the right of the Image Texture node marked Color, and drag it to connect with the input dot that says Color on the Diffuse BSDF node. Note: input nodes are on the left of each node, and output nodes are on the right. You connect nodes left to right, input -> output.
Congratulations, you have just mastered Node editing.
Now use “Add -> Vector -> Mapping” to add a mapping node. This will allow you to scale and rotate the bitmap to match the size of your object. Connect the output noodle marked Vector to the input dot marked Vector on the Image Texture node.
The default on the Mapping node is the Point tab. Change the scale until the texture looks correct in the preview-rendered image in Camera viewport.
Finally “Add -> Input -> Texture Coordinate node” and connect the Generate output noodle to the input dot on the Mapping node marked Vector.
That’s it: you have a textured sphere. Okay, it won’t win an Academy Award for visual effects, but it’s an object you made, and it’s textured. We’ll get into bump, diffuse and specular highlight maps and UV texture mapping in a forthcoming article.
If you have any questions about texture mapping and making textures in Blender, let us know in the comments below.