A few basic questions about functions that are capable in Blender.

I am trying to use Blender3D as a CAD program for my Fedora core linux box. I have a friend who is very good with this program, and said it will work well as a CAD program. So far, I am pleased.
So I am reasonably advanced in working with AutoCAD, and while trying to draw, there are a few things I have not yet been able to figure out.

When selecting vertices in a shape, is it possible to make a box while holding the mouse, and having all vertices in that box selected?

Also, say I have a circle which I have extruded up in the Z axis .5" (or BU i think is the proper unit now), how can I fill this in so that it is actually a cylinder? Or at least make a face on it. I tried pressing space>add>mesh>cylinder>scale>enter #6 for 6" which is what I want. BUt it made it 6" in the X,Y, and Z axes.

I did complete the first few tutorials in the wikibook “noob to pro” for blender, it was helpful in becoming familiar with the general interface, but I have always learned better by figuring it out myself.

not sure what a ‘CAD’ program is, but if the same as blender then this should work:

answer to first question - hit the Bkey and drag the left mouse button

second - select the verts you want to be a face and hit Shift-Fkey (if you have 4 verts or less hit the Fkey by itself to make face/edge
- after hitting Skey then ‘6’, hit Zkey, and it will scale it six units on the Z axis

i hope this is clear and answers your questions!


how can I fill this in so that it is actually a cylinder?

Look at Greybeard’s post here:


By the way, you can scale along axes. Hit the SKEY to scale and then hit x, y, or z, to restrict the scaling to one axis. Hit shift-x, shift-y, or shift-z to hold that axis the same while scaling the other two.

Bah- I’m not sure if Blender works well as a CAD substitute… it seems that CAD has alot of useful funtions that Blender doesn’t (according to my dad, anyway ;)) (but don’t go by what I say- I’m still a newbie)… why not just stick with CAD?

There is a python script that will help simulate CAD conditions, although it is not a perfect substitute as it doesn’t support the more advanced features CAD offers. (Its called BlenderCAD, google for it)

If you really want CAD go with AutoCad or an on-par equal. As much of a fan as I am that blender can really do everything, CAD may not be one of its strong suits as the community decided a long while ago (while NaN was still around) to cater more to the artist than the designer/engineer.

I know there are some open source CAD projects around, definitely try Sourceforge and Google. I can’t really think of any off the top of my head, and they are (to my knowledge) still leagues behind CAD, although they do have some of the more useful features that Blender lacks on the engineering side.

While you can model precision in blender using one BU=1cm, 1m, 1km, etc, it becomes tedious as you then have to be sure vertices are positioned exactly via the ‘n’ button where you manually enter vertex location.

I’m working on a project that eventually will be drawn as a CAD drawing, but the animations are needed first for marketing reasons. So I’m designing the entire vessel and some piping to scale (1m=1bu - which gives me precision to the nearest mm). I started by drawing a line at exactly 1m, and leave the object size at sizex/y/z=1.000. That way If I need a line of different lengths, I just scale my “meter stick” to the length I need. I’ve created pipe, fittings and structural steel all dimensionally correct. (We need to do clash detection at the same time, so precision is vital). It’s not quite as fast as ACAD for replicating a 2D drawing, but autocad 3D is painful to work with. Since I can export to DXF and bring my mesh into AutoCAD…I’m laughin’!

I use the snap function in Blender to get my things where I want. It’s slower than a CAD snap function, but better than eyeballing it or using the N properties dialog. (snap cursor to selection, then snap my other vert/obj to cursor).

(I did learn, however, that the mesh name in blender can make your DXF file corrupt if you put in non standard “dos filename” characters. I leave everything.like.this for naming my meshes, and they get converted to something_like_this as a block in Autocad (at least in 2005).)