Adding Geometry after UVing .. prevent stretching?

Hi Guys,

Couldnt think of a better title to describe this.

I was looking at a tutorial over at called “Making of a Victorian Building”. However this was done in 3DS Max:

The tutor added a texture to a mesh, seems to have UVed same and somehow then adds extra edges after UVing without stretching occuring. It seems the method is add a texture and then indent / shape the underlying mesh via adding more geometry for window areas, roof overhang etc.

What is the best way to do this in Blender?

In step 1 it is mentioned “Added an edit mesh modifier.”

“You put an edit mesh modifier between the poly and the UVW modifiers because otherwise, as you push and pull edges around, you’ll see your texture stretch and mess up in your 3d display.”

I know edit mesh modifier is a 3DS Max thing - but is their a similar proceedure OR way to do this in Blender?

Of course maybe i have completely misinterpreted whats going on here - If so please put me straight :smiley:

You can add edge loops and check “Correct UV’s” option available in tools shelf or accesible via “F6” immediately after adding edge loop. after checking the option, you can use “Edge Slide” to work with geometry.
In any case, you’ll be tweaking UV’s , but it will preserve most of it intact.


I tried this. Im using latest 64bit windows build. I create an edge loop but neither F6 or stuff in toolshelf is available - it is at best greyed out. Once the edge is added and before committing it their are not any available tickable options. Maybe I am doing something wrong.

It was a problem that has been very recently corrected.

But you need a very recent build of Blender (more recent than the stable Blender 2.66a) to benefit from the Correct UV option not being greyed out :

Or wait until Blender 2.67 is released (it will have the fix too) in a week or two

I have sort of cracked it. Here is a quick render:

I created a portrait type plane, rotated it to face me in the front view. Added the texture image to the plane. In the workspace front view I started adding edges at the important points ( above / below windows ). Extruded out the window sills. Extruded “in” the windows. Individually “retextured” the window polys, sill polys etc by selecting first in workspace, facing the polys toward me on the screen and using UV UNWRAP // PROJECT FROM VIEW. Then off to the UV/Image editor and moved or adjusted these polys to the correct place on the image/uvmap. I extruded the outer edges back to give the building depth and then went to right / left view, selected all the side polys and once more used UV UNWRAP // PROJECT FROM VIEW. Choose an appropriate area on the image in the editor to texture the sides.

Here is a non textured version:

I never found out how to add an edge ( ala that MAX tute above ) AFTER UV UNWRAP and then be able to move the edge around WITHOUT stretching the texture. BUT some may say why do you need this. The only reason i can think of is to micro adjust the edge after applying it without upsetting the UV Texture.

Any other input appreciated of course.

I use daily builds from:

What you say isnt sorted in these yet it seems?

In 3DS Max, the UVW map or mapping modifier is not unwrapping the model as in “defining seams and then unfolding it to lay it flat on a plane”. The UVW Map is just a planar, sperical, box (or whatever type of projection) mapping of an image to geometry. Max (and Blender for that matter) doesn’t care what is inside the mapping box (if you chose boxmapping). It just projects the image from the faces of the mapping box to whatever is inside.
It is not technically unwrapped (like in Blender hitting “u” and then “unwrap”). To do that in 3DS Max, you apply an “Unwrap UVW” modifier.

I use r56372 and when i add a loop then move it, if i press F6 i can enable “Correct UV” and it works

the same if i make an edge slide (CTRL+E -> Edge slide or select an edge and press G 2 times)

No idea what you’re doing wrong if you’re using the latest buildbot version.

I had a version installed from mid last week. I just installed r56372 and all works fine now. They must just have fixed this? As you said yourself in a previous post here … Thanks

Yes it’s very recent, the fix for the edge sliding was yesterday and the fix for the loop cut was the day before

Thanks all for help. Progress so far: