In the UVImage Editor header I need to know what the “Active UV Map” selection box does.
By my intuition I thought it was a way to assign different Tangent Nodes to different parts of an object’s mesh. For this to be true I expected a different UV Map to be possible for each selection of “Active UV Map”. I expected when I use the U Key in 3D View to do a mapping, that mapping would be assigned only to the named map currently selected in that “Active UV Map” selection box.
I find this not to be case. After I do several mappings I find that when I create a new mapping to select from in Properties => Object data => UV Maps, and change to that in the UV Editor’s “Active UV Map” selection box, all the mappings I did before that change remain displayed (when their vertexes are selected in 3D View). I did not see any difference between the two “Active UV Map” selections.
What does the “Active UV Map” selection box do? Can different Tangent Nodes be assigned to different faces on the same object?
I find that when I create a new mapping to select from in Properties => Object data => UV Maps, and change to that in the UV Editor’s “Active UV Map” selection box, all the mappings I did before that change remain displayed (when their vertexes are selected in 3D View). I did not see any difference between the two “Active UV Map” selections.
When you create a new UV map, it starts life as a copy of the active one. So if you haven’t yet made any changes to the new one, you won’t see any difference.
Can different Tangent Nodes be assigned to different faces on the same object?
I’m not sure what you mean by ‘Tangent Nodes’. You only need multiple UV maps in order to get different unwrappings of the same face; even with just one UV map different faces can already be unwrapped completely independently of each other.
I’m not sure what you mean by ‘Tangent Nodes’. You only need multiple UV maps in order to get different unwrappings of the same face; even with just one UV map different faces can already be unwrapped completely independently of each other
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I know that different faces can be unwrapped to the same UV map and I have already done this. But if a single UV Map has several unwraps is there a way to assign each unwrap to its own Tangent node in its own Cycles material? The only way I saw to do this was with different UV Maps because the Cycles Tangent node seems to take only an entire UV Map as an input.
When you create a new UV map, it starts life as a copy of the active one. So if you haven’t yet made any changes to the new one, you won’t see any difference.
When a new UV map is made, and an unwrap that is not desired in the new UV map is copied from the pre-existing one, is there a way to delete that unwrap in the new UV Map? I find the usual X key for deletion that works in every other circumstance does not work in the UV Editor. Nor does the keyboard’s delete key. I cannot find a command to delete one in the UVImage Editor’s menu. Can it be done? If not it means I have to establish in advance how many wrappings I need and create this many blank ones before start doing any unwraps. And after starting the unwrapping task I find I must have more UV Maps than originally figured, I have to delete all the UV Mappings and start over.
I have realized how it is done. In 3D View, in the pop up menu that opens in response to the U key there is a “Reset” item that deletes all the wrappings. There does not appear to be a way to delete an individual wrapping.
I have also have seen that vertices are assigned a material in Properties => Materials. Here there is a list of material links. The highlighted one is the one the selected vertices are assigned when the “Assign” button is pressed. A link is assigned a material by the Material Browser that is below the Assign button and also in the Node Editor’s header.
A material applies only to the faces that are assigned to it. The UV coordinates of any other faces in the same UV map are completely irrelevant, so there is no problem with different materials using the same UV map. To repeat my previous statement: you only ever need multiple UV maps in order to get different unwrappings of the same face. For example, if you have one layout of faces for the diffuse texture, and a different layout for normal mapping, then each face needs two different unwrappings, so you need two UV maps. But if your mesh has 100 different materials, you still only need one UV map for a basic diffuse texture, since each face will only be assigned to one of those 100 materials.
When a new UV map is made, and an unwrap that is not desired in the new UV map is copied from the pre-existing one, is there a way to delete that unwrap in the new UV Map? I find the usual X key for deletion that works in every other circumstance does not work in the UV Editor.
in the pop up menu that opens in response to the U key there is a “Reset” item that deletes all the wrappings. There does not appear to be a way to delete an individual wrapping.
Every UV map contains coordinates for each vertex of every face. You can reset them, or hide them, or move them out of the way, but you cannot actually delete any individual coordinates. Resetting is not deleting: it sets the UV coordinates of each face to be the entire UV space. All the UV unwrapping commands (including reset) apply only to the faces selected in the 3D view at the time; if you want to reset only some faces, just select those faces.
Yes. If you add a UV map to an object that did not previously have one, but do not perform any unwrapping, you will still have a mapping for the entire mesh. By default, each quad face is mapped to the entire UV space, with one vertex at each corner, while tris have one vertex at each of three corners; I’m not sure what the default is for N-gons. Resetting restores this default.