Animating extrusions ??? Help :)

Hello all:
I am fairly new to Blender but have followed through on a couple of tutorials online. I have a project that is a 2d floorplan of a house. I would like to animate the walls growing out of the 2d floorplan (extrusion) but can’t seem to figure it out. Could anybody give me any tips?

I have tried adding a cube at frame 1 and inserting a size key. Then at frame 50 extrude it upward adding another size key and doing al-a but it doesn’t work.

I can do a work around by building it then animating a plane moving down it but wanted a more elegant solution.

Thanks for any help.

Hi and welcome.

Not quite sure but I think you mix up two things.

Extrusion (E-Key) is a modeling tool that and can’t be keyframed.

Scaling (S-key, restricted scaling with S-key +MMB, or N-key for numeric input) is a method that can be keyframed and refers to the Size key frames.

Therfore, to animate the grow of a plane you would have to set i.e. SizeZ =1 in frame 1 and SizeZ=5 in frame 50.

The scaling method should look ok for walls without windows.
Probably best is to set the center point (small pink sphere) to the bottom of the mesh before scaling (in Edit mode select a vertex of mesh’s buttom, Shift+S --> cursor to selection, Object mode --> center cursor). This way the walls will only be scaled in one direction of the axis (with restricted scaling).

For walls with windows this could look a bit odd.

In this case an animated blend --> Lin, Quad, or Ease texture for the alpha value of the wall’s material could be better.

A third method could be the use of a Build Effect for a highly subdivided wall mesh.

Hello there!

I think the answer to what you’re trying to do is RVK’s or “Relative Vertex Keys.”

It works like this (in VERY basic… do a search here for RVK tutorials and you’ll get some good stuff). 2.28 Blender has a new method for doing this that saves you the steps of turning on “Relative Keys” and deleting the “speed” curve, BTW.

  1. Create your basic mesh. Make sure that it has grab-able vertices everywhere you want the walls to “grow.” IMPORTANT!! You can’t add or subtract vertices from a relative key, so make sure you have already started the extrude even if it’s a TINY bit… or better yet “underground” so it can’t be seen. Otherwise this doesn’t work.

  2. With the floor plan selected in Object mode (i.e. not in Edit mode), hit the “I” key in the 3d window and select “Mesh” from the list of possible keys to Insert. From the next menu select “Relative Keys” and that will set you up to move on. You’ve just created your “base” mesh.

  3. Without changing anything else, hit the “I” key again, and select “Mesh” again. You’ve just created your first “relative key.”

  4. Split your 3d window, and in one side choose the “Action Editor” (or do this in the same window, as you choose). You’ll see a “sliders” bar. If you don’t see “key 1” below that, turn the little “arrow” triangle down by clicking on it. You now have a slider from 0 to 1.

  5. Tap the left arrow key to advance frames, or simply type in the frame number where you want your highest “walls” to be.

  6. Move the slider from 0 to 1, and advance one more frame. You should see an orange block appear there if you have automatic keys turned on.

Preview your anim, and your walls should smoothly grow!

Good luck!


Why not have the walls fully modelled, but just below the level of your ground plane? Have them rise out of the ground plane by simply moving them upward.


Just give him the EASY way, Harky.

Just like a prepress manager, I tell you.

(Personally, I like a combination of that method and the method suggested above which uses animated alpha mapping to fade in windows & doors and such without dealing with increased vertex counts.)

Good luck!


Nice one, Harkyman!! %|

Standles just said he could animate a plane moving down but he wanted a more elegant solution."

so what do you propose? Right, animate the walls moving up… Way more elegant… :smiley:

:wink: UglyMike


Err - yeah, he did say that, didn’t he? Truthfully, I had made a little mockup, with a backbuf image and the covering plane textured with the same image as shadeless win coords, so it looked like the walls were growing out of nowhere, but forgot to include that part.

Thanks for all the help. As for the elegant solution… well I decided to modle the walls below grade and animate them upward. I will work on the elegance as new versions.

I tried animating the scaling with some success. Will continue to look into that technique.

As for RVK… Lets just say “color me confused” :slight_smile: I will look at some tutorials and see if I can figure it out.

It is nice to have multiple ways to attack a problem. Never know when an alternate technique learned will save your can one day.

Thanks again for all the help and quick advice.

I did use the animated alpha to fade out the doors.