I have imported a glTF model of coral reef. It is good but has a huge polycount. I have a created a low poly copy but when I look at the uvs and texture image of the high poly import the uvs on the texture image are disjointed.
This is the high poly model
If I want to change the colour or quality of a portion of the model, it is almost impossible to do it because the uvs are not organised together to make changes to the image texture easy (in an external photo editor)
Is there a workflow that will re-arrange the uvs more stragetically so I can make improvements to the quality of the image and then apply it to the low poly mesh.
I have found an acceptable solution, particularly based on Arthur's advise below.
I baked the texture image from the high poly to the low poly mesh. The secret is to UV unwrap 'Projected from View' having positioned the high poly mesh at the correct perspective/angle. The results as follows.
The low poly model in object view (right) and the new image baked from the high poly mesh:
The low poly model in edit mode with vertices selected (right) and those vertices shown on the new texture image (left).
This now makes alteration in a specific area of the image easier to identify in an external photo editor.