Just today I stumbled upon this again and wondered why it is the way it is.
If you create a plane, unwrap it, add a material and texture, set it to image and load it, oh joy, it shows up in the viewport and in the render.
Now, I want another texture and go to the texture tab and load another image.
Sometimes the image loads and shows up in the viewport.
Sometimes the image loads and does not shop up in the viewport, then you see the old texture in the viewport and it renders the new texture.
Only way to change the texture in viewport is to go to editmode, to the UVImageEditor and switch to the other texture and leave edit mode again.
So, why is this happening? The plane is just a random example, it usually happens to me in complex scenes I’ve been working on some time.
seems to me that the image seen in viewport is the one selected in UV editor only!
not certain why but in a way it makes sense cause you may have many texture channel images
so need to show only one which is the one selected in UV editor i think !
Building on what Ricky implies , It comes down to priority.
The idea is that textures assigned in the UV editor take priority over those in material/texture slots is so that you can visualize an individual texture from a material ( for instance the UV grid in favor of a dirt texture ).
I try to abide by that design principle and only assign a image in the UV editor if I need it for some reason ( image painting and such). All in all I have to do that about 2% of the times I have to create a model with UV and textured material.
Sorry, but there’s no such principle as “only assign in the UV editor”
Else the texture would appear in the viewport if you’d unwrap the object and load the texture in edit mode in the UVImage editor.
But it does not, it only appears if you also add it as texture to the material.
If I assing a material and texture to an UVmapped object, the texture is rendered, and shows in GLSL textured viewport.
If I change the image texture in the material editor, it changes for the render AND for the viewport.
And here’s the gag: Not always, sometimes the old image sticks in the viewport and the new one is only visible in render.
Personally I’d say that whole thing is rather inconsitant, that’s why I wanted to know if there’s a reason why it is the way it is, and why sometimes the texture changes, and sometimes not.
It’s as painful as loading brush textures for texpaint or sculpting, especially if you have lots of textures to change, you can always do it twice, once for the viewport, once for the rendered material, but not always - sometimes it magicall works, sometimes it doesnt.