Blender 3D: Noob to Pro/Image Editor

Blender’s UV/Image Editor window serves a number of related purposes:
 * It is a place to view rendered images, and save them to files.
 * It is a place to view and edit images being used as textures.
 * It is a place to perform UV mapping of meshes to texture images.

In the window header, you will see “View” and “Image” menus, followed by a menu for choosing which image to view. The rest of the window header varies depending on your choice from this last menu.

Viewing Render Results


Here is what the variable part of the window header looks like when you choose the special “Render Result” entry in the image-selection menu. The next menu, showing the word “View”, serves no useful purpose in this case (it is only applicable to editable images, not the render result). Next to that is a Slot menu, allowing you to select from any of 8 numbered slots. Each slot can hold a separate Render Result image. This is handy for trying out different render settings (e.g. quality etc), and quickly flip between them for comparison. You can also use the keyboard shortcuts .. to switch slots. When you perform a render, the generated image is put into the slot you are currently viewing in the UV/Image Editor.

The next two menus, showing “RenderLayer” and “Combined” in the above screenshot, allow you to view different render layers and render passes, if you have more than one of these configured in the render settings, as well as the final compositor result.

The rightmost group of four icons make a further breakdown of the image into RGB channels with/without alpha transparency layer, alpha on its own, and Z (depth) buffer on its own. Alpha transparency only matters if you are rendering a transparent background in place of the sky, as discussed later.

Viewing/Editing Texture Images


Here is what the variable part of the window header looks like when you select some other image, or create a new one. Now the editing-context menu becomes useful: selecting the “Paint” item lets you paint on the image.

Note the rightmost group of icons in the header has shrunk slightly: there is no more Z-buffer option, though the alpha-related options still exist.

UV Mapping


Here is what the variable part of the window header looks like when you select a texture image, and go into Edit mode on a mesh in the 3D View window.