Architectural modeling tip: How to offset faces in Blender 3D

In some CAD software's and 3d packages as well, there is a tool called offset that can create parallel copies of faces and edges. If you create architectural models using Blender 3D and have used some of those tools, you probably miss this type of feature. Even not being available as a default tool or modifiers, it doesn't mean that Blender can't do an Offset for faces. There is a very nice script that came along with Blender 2.48a called solidify selection created by Campbell Barton, witch works pretty much in the same way as an extrude from software's like AutoCAD or 3ds Max. The name of the tool can differ in that software's, but it is there, and it's a great help in geometrical modeling.

Here is an example of how this script can be useful. Imagine that we have a wall, made by a series of faces and an arc. As you can imagine, this wall is a composition of a series of planes.

blender3d-offset-modeling-architecture01

If we try to create a solid wall by selection those faces and creating an extrude, the result won't be exactly a wall:

blender3d-offset-modeling-architecture02

The arc makes everything a mess of faces.

With the use of Solidify selection, we can manage to create the wall using a technique similar to the offset.

It works like this, first we have to select the faces that will be solidified. When the faces are solidified, select the script in the Mesh scripts folder. There are basic only two parameters to worry about, which are:

  • Thick: Distance from original faces to the copies
  • Skin edges: Turn this button on to create faces connecting the original and copied planes

blender3d-offset-modeling-architecture03

The direction of the copies are controlled by the normal's of the faces that e are editing. If something goes wrong, like faces copied in opposite sides, check the normal's. If all normal's are pointing to the same direction, everything should work fine.

blender3d-offset-modeling-architecture04

There are a lot of applications for this script, for modeling walls and other structural elements and especially in furniture modeling, where we have to deal with curved surfaces all the time.

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Comments

  • KevinW
    Reply

    You can do this example with the built in “Shrink/Flatten along normals” tool (Alt-S).

    Still, I bet I’ll find a handy use for this script somewhere.

    Thanks for posting this.


    Kevin

  • Jerry Yoder
    Reply

    Allan,

    I really could have used this a little while ago. This is a great little script. It would be nice if Blender would build these into the program.

    Thanks for what you are doing with this website Allan. It helps me a great deal!

    Jerry

  • reezjer
    Reply

    Once again a great tut !!

    Thanks

  • Mats Halldin
    Reply

    Indeed, a great tool. Thanks for sharing! (You to Kevin.)

    / Mats

  • LuisM
    Reply

    For me it doesn’t work in the proper way, like in your images is possible to see: in my case the new faces are generated scaled, bigger when thick is positive, smaller when negative.
    What’s the problem?
    Thanks.
    Great blog!

  • Toni
    Reply

    I’m having the same problem than LuisM. Any ideas?

    Thanks.

  • LuisM
    Reply

    Toni, sorry, I already know what’s the problem, but i didn’t put it on.
    If you do just like in the example exposed by Allan, it works. We had the problem because we didn’t solidify just a groupe of “vertical” isolated faces but a group of vertical faces belonging to a bigger group including “horizontal” faces also.
    If you add a floor to the example probably you’ll find the difficulties we had reported previously.
    I hope this will help.
    LuisM.

  • Shariq Mushir
    Reply

    This is a nice script. Thanks for the cool information. Also as far as Shrink/Flatten is concerned I don’t think it’s the same as offsetting.

    S/F resizes the polygons in the direction of vertex normals whereas offsetting resizes and moves all vertices towards the median of the selected faces.

    Maya allows you to offset polygons while being extruded and otherwise.

    A good example would be how Paths are offset in Adobe Illustrator.