Looking for help to make CAD tools for blender w/Python

[kosty]

Below is my post from a thread on this ng re: "a CAD fork of blender?"

--snip--
What about another approach -- rather than a fork... Leave the underlying 'engine' intact and build a series of tools as python scripts. Or would this be to clunky an implentation?

I'm picking up some info on Python over the next few days so I can get started with the following:

1- dimensioning
2- a reference file manager(???)
3- a tagging utility for windows, doors, and the like...

These are my opening thoughts on the subject. What else?

RSVP & thanks,

John K.

[Rangel]

I already am building some. Having Pyhton scripts to make CAD like modeling easier would be great!

Alexandre Rangel

[kosty]

Alexandre,

Thanks for the reply -- and please spread the word. I have a few people in my area LUG that might get involved as well as some crossovers from:

http://www.freelists.org/archives/cad-linux/

Above is the archive. You might want to joint the mailing list.

Also, what type of work / architecture models are you doing?

[Arathorn]

Do you mean just Blender with some CAD features or a complete Pro Engineer-Blender hybrid like thingy (although that would be a damn lot of work).
I would really love the latter, the the forst option would be very nice too, as far as I know there are no open-source cad programmes.

[kosty]

Originally Posted by Arathorn --snip-- as far as I know there are no open-source cad programmes.

Hopefully, the tide is beginning to turn. In the meantime, check out the following:

http://xspace.sourceforge.net/wiki
http://bugbear.blackfish.org.uk/~bruno/draft/
http://pfrostie.freeservers.com/cad-tastrafy/
http://www.freelists.org/archives/cad-linux/
http://www.freelists.org/webpage/cad-linux-dev

[djfuego]

On a proffessional scale sorry, Autocad will rule and has done for too many years. Although modelling stuff in blender is easy there is no way to get true dimensions unless you can code something up in python. One hell of a job.

[Arathorn]

Yes, Blender would need a lot of work to get at such a level.

Those open-source projects look promisefull, I already searched a bit on sourceforge but couldn't find anything.

[kosty]

Originally Posted by djfuego On a proffessional scale sorry, Autocad will rule and has done for too many years. Although modelling stuff in blender is easy there is no way to get true dimensions unless you can code something up in python. One hell of a job.

On a large scale, I fear you may be correct. However, if I could split my CAD load effectively between Blender and, say, ACAD Lt, I'd be a happy camper. I understand that Blender != CAD and was never designed to be but I can dream can't I? ;-)

[kino]

hi
there is a python script to make some architectural object
at zoologique

http://www.zoo-logique.org/3D.Blende...hp/python.php3

ArchiMause
http://www.zoo-logique.org/3D.Blende...use05c228a.zip

windows, walls, ramps

it work fine , you need to understand french

ciao
kino

[CrackerJack]

I love Blender.
It's great for artistic modelling and animation.
And having some CAD-like tools would be great.

But I don't believe that it is anywhere near being a useful CAD application.

I mean, if you wanted to make something a specific size you could use the grid and numeric input to put each vertex/control point exactly where you want it. And scripting something to make that easier, or expand the modelling toolset would be great.

But if you want to be able to do *real* 3D CAD, you need to add a lot more than the ability to bevel edges or dimension objects.

You need the capability for parametric feature-based solid modelling.
This is what all the big name 3D CAD apps (Pro/E, SolidWorks, Inventor...) are based on.

It would be an enormous leap from what blender was meant to be. It would be kind of like trying to use a screw driver to drill holes. You might be able to get there eventually, but it's really the wrong tool for the job.

You would probably be better off trying to start from scratch then to retro-fit Blender into a truely useful CAD app. I think it would be incredible to have a good Free 3D CAD program, but I don't think we Blender is the answer.

Just my $0.02.

J.

[kosty]

All of these are valid points. Please keep them coming -- positive AND negative.

Blender as a modelling engine shall remain intact. Getting under the hood and re-engineering is far from my goal. I'm more interested in adding lights, guages, signals, if that's an apt analogy(?) by making it "appear" friendly to a CAD user. Good modelllers are not -- necessarily -- artists, though IMO, that certainly helps. I would merely like to have some keyboard or gui stack-ons which allow me to, say, create a model of my mom's house -- an ongoing, long-distance renovation project for my sister and myself -- and cut it into various views. Ie: floor plan; roof plan; elevations; details -- all with appropriate labels for printed output. Agreed, that sounds like a lot of added widgets when there are perfectly good 2d CAD packages already available. However, many of those are piss-poor modellers and it seems to me -- though I'm not much of a programmer -- that it is easier to turn a modeller into a 2d output platform than the other way round. If I am I way off in this assumption, it won't hurt my feelings to be corrected. ;-)

Thanks and RSVP,

John K.

[~ox{]

I think it is a very good idea to have such a python script. As an artist I am very interested in an ecclectic approach to creation and i am very interested in structural accuracy in some of my artwork. Such a script would fill a big need for linux artists.

[atollo]

Not quite on topic but it's my current workaround to the CAD problem - specifically product design - which may be of some use to people.

I currently use Blender for assembling & rendering quite complex product prototype images, packshots & instructions for a construction toy.

I make the components & sometimes the assemblies in a package called ProDesktop Express. This still appears to be available for free (& apparently even for commercial use according to the license!) here:

http://www.ptc.com/products/desktop/express/license.htm

Just click thru the license agreement & download. During the install you'll have to provide a valid e-mail address @ some point so they can send you an activation key. (As far as I can remember - its been a while)

I've been using this for over a year now & only had to reapply for the activation key once few weeks ago (which they sent thru no probs)

It's about a 32Mb download.

It's a fully functional solid modeller (not quite Pro Engineer but more than adequate for quite a few things) but it has a v basic renderer can only really do solid shaded screenshots which are not true in perspective.

It also has a good 2D Mechanical Drawing component.

The learning curve may be a bit steep if you're not used to CAD or 'high end' 3D packages but it comes with a good online help.

It exports to a variety of formats including IGES, STEP (both good for CADCAM) & VRML.

To get stuff into Blender I export to VRML & import into Blender Publisher. Fiddle with the model - rescale & reference duplicate objects to single meshes to reduce the file size & make applying materials easier- then save. Then reopen in Blender 2.3 to light & apply materials.

Hope this is helps.

C

[Rinkhals]

Art Haas has written pythoncad (www.pythoncad.org) which, among other things, can interpret AutoCAD Drawings: has anyone looked at an implementation of some of these python routines in Blender?

Personally, what would interest me would be some way of using the way I work in AutoCAD to generate Blender files. IE, using 'Offset', 'Extend', 'Fillet', etc. to control the drawing interface.

Dave Coventry(Rink)

[MattWeth]

It would be great to see real-world scaling / dimensioning in blender, but I can't see it being able to compete with architectural modelling / rendering packages - it just has a different focus.

However, if it did, IFC support (Industry Foundation Classes):
http://www.interoperability.org.au/3562.html
would be good to see.

just my 2p

Matt

[kosty]

Originally Posted by Rinkhals Art Haas has written pythoncad (www.pythoncad.org) which, among other things, can interpret AutoCAD Drawings: has anyone looked at an implementation of some of these python routines in Blender? Personally, what would interest me would be some way of using the way I work in AutoCAD to generate Blender files. IE, using 'Offset', 'Extend', 'Fillet', etc. to control the drawing interface. Dave Coventry(Rink)

Dave,

Thanks for the tip on PythonCAD -- I had completely forgotten about that project. I'm downloading their code as I write this. It should save me much wailing and gnashing of teeth.

On your second point, I would love to be able to mimic my AutoCAD or Revit keyboard setup. From what I've read, this should now be possible under 2.3. I'm a newbie's newbie at Python so it may take me a while to get up and running.

Thanks,

John K.