Baking in Blender allows you to transfer different aspects of your rendered scene/model to a 2D planar projection, or UV map. This is primarily used for creating Normal Maps but can also be a very helpful aide in texturing, render time optimization, etc.
Before we dive into the specifics, let me give you a quick crash course in baking.
In order to bake out the necessary maps, the three requirements are that you have at least one mesh, that the UVs of that mesh have been unwrapped and that you have applied an image to the UVs of that mesh. Beyond this, it all depends on what you are doing. To bake out an object:
- Select all vertices of the default cube (or any object of your choice) in Edit Mode, press U > Unwrap (smart projections) > OK
- Switch your viewport to the UV/Image Editor, select all UVs with A, add a new image by going to Image > New > OK
- Under the Render properties, in the Bake panel click Bake.
- If all is correct, you should now see the results of the Full Render bake in the UV/Image Editor.
You should see something like this:
With the default Blender settings, you will get this result. As you can see Blender is baking out all of the lighting details of our default cube and saving it to the UV mapped image.
These few steps are all it takes for most baking purposes.
This is the basics of baking. Of course we did not yet bother to adjust anything or to select the method of baking needed, and so the results are quite useless. However, if you were to adjust the lighting to fit a specific purpose, as demonstrated further in this tutorial, you would see very different results. Let us now examine each of the different kinds of bakes and how to use them.
Baking the Full Render enables you to bake out everything you see at render time, this includes lighting, materials, textures, and ambient occlusion. When used correctly this can be very helpful for transferring procedural materials to a 2D color map or for baking in the lighting details of textures to be used in ultra lowpoly games that do not offer dynamic lighting.
Here is an example of procedural materials that have been baked out to our cube using the default lighting setup:
Here is the same cube and same material with a basic 3-point lighting setup:
This baking method is very useful as an aide in the texturing process. When texturing, particularly for lowpoly models, creating realistic shading from light can be quite difficult. Using Ambient Occlusion baking can ease this process by giving you a plane, shaded map of your object in 2D. This is best demonstrated with an image as seen below:
Here is our same cube and same material with ambient occlusion:
As you can see it is plain grey, this is due to our cube having no variation in the surface and thus nothing to affect the lightness and shadows.
Here is a modified cube with surface variation:
Due to the modified surface I have also re-unwrapped the UVs using Smart Projections.
Shadow baking is also helpful for lowpoly game models as it allows you to apply all of the shadows to your textures for static shadows.
Using the same cube from above with surface variation, here is my result:
A good way to use this is to overlay it over your texture maps using blending modes. This is nothing more than an alpha map of sorts.
Possibly the most widely used baking option, the Normals allows you to create normal maps for low poly models from a high resolution version. This is done by used the Selected to Active option, which will cause Blender to bake the normals from the secondary selection to the primary selection in your viewport.
Using the two cubes again, here is what you get, baking the normals from the surface variation cube to the default cube:
As you can see, it also bakes out the normals from any bump maps you have added to your material (in this case I have a slight Nor value applied to my Marble texture).
You will also notice that you can change the space for normal baking. By default this is set to “Camera,” but in most cases you will use either “Object” or “Tangent.”
This baking mode is used to transfer all texture channels details to your UV map. Texture baking ignores all lighting and other variables and bakes out strictly the texture details. This one is about as simple as it gets.
Here you can see the result of the surface variety cube with the textures baked:
Next to Normals, Displacement might be the most useful baking mode. It allows you to bake out the displacements from one object to another. These displacement maps can then be used as a displacement map in game engines, Blender’s renderer, or even substituted as bump maps anywhere they are needed.
Here you can see the displacement details baked from our cube with variation to the default cube:
As with Normals, it is important to check the Selected to Active option.
That is it! I have just given you a overview on Baking in Blender. Although, there are more options you may play with to fine tune your results, that is the gist of what you need to know for most cases. It should definitely get you started.
In this article, we have learnt all the basics that are essential to start off with baking in blender.
If you have read this article you may be interested to view :
- Modeling, Shading, Texturing, Lighting, and Compositing a Soda Can in Blender 2.49: Part 1
- Modeling, Shading, Texturing, Lighting, and Compositing a Soda Can in Blender 2.49: Part 2
- Creating an Underwater Scene in Blender- Part 1
- Creating an Underwater Scene in Blender- Part 2
- Creating an Underwater Scene in Blender- Part 3
- Creating Convincing Images with Blender Internal Renderer-part1
- Creating Convincing Images with Blender Internal Renderer-part2
- Textures in Blender