Baking a texture map out of Blender is not exactly an intuitive process, especially when using the Cycles Render engine. So here’s a few quick tips for baking Normal and Ambient Occlusion maps out of Blender. I will assume you’ve already done some sculpting on the model using the Multiresolution modifier and the Sculpt tools.
First, the model needs to be UV mapped. The textures will be baked according to the layout of the UV map. So this is necessary before you begin. For more information about UV mapping in Blender, check out my Youtube videos on Blender UV Mapping and Blender Character UV Mapping.
Once you’ve UV mapped your object, you will need an image to bake to. In the UV/Image Editor click New and create an image. Give it a name, like “character_NOR” so you know what it is and that it’s a Normal map. Be sure and save this image by going to Image > Save As Image. The file needs to be saved to your hard drive.
If you don’t already have one, you will also need a material applied to your object.
In addition, you need to have a texture node in the Node Editor with your saved image. So in the Node Editor, click the Use Nodes checkbox so you can see the nodes of the material. Now press Shift + A and go to Texture > Image Texture to add an Image Texture node. Click on the pull-down menu next to the Open button and choose the image you just created and saved.
Now you’re ready to bake. In the Render window, scroll all the way down to the Bake section. Change the Bake Type to Normal. And click the Bake button.
You should see your Normal map appear in the UV/Image Editor. If it’s just a flat purple image without any sculpt information, you may need to turn on Render button in the Multiresolution modifier. This will effect the bake.
Now go to Image > Same Image to save the changes to your hard drive.
Ambient Occlusion Map
Baking an Ambient Occlusion map is a very similar process.
You will need a new image. So click the + button in the UV/Image Editor to create a new image and give it a name like “character_AO”.
In the Node Editor, change the image in the Texture Node by clicking the pull-down menu next to the file name and choose the AO image, in this case it is character_AO.
Now in the Render Window, go to the the Bake section and change the Bake Type to Ambient Occlusion. And then click the Bake button.
Now an Ambient Occlusion map is created. The resolution of the AO map is controlled by the render samples of the scene. So if your AO map is grainy or pixelated, go to the Sampling section in the Render Window and increase the Render Samples.
Once again, in the UV/Image Editor click Image > Save Image.
And there you go, baking out a Normal map and AO map isn’t that difficult. It just isn’t very intuitive. Hope that helped.
For more Blender goodness, check out my Blender Character Creation series.