Parametric Constraints and 3D?

[tzframpton]

Now that I'm getting much more familiar with Revit, I am really loving the true parametric environment, especially for 3D objects. I know that AutoCAD finally introduced Parametric Constraints a few versions back but are they capable of being used with 3D solids at all? Has anybody attempted this?

 

If so, looking to start a good discussion here. Thanks in advance.

[ReMark]

I don't believe they are.

 

"Parametric drawing is a technology that is used for designing with constraints. Constraints are associations and restrictions applied to 2D geometry."

[JD Mather]

I find the constraints painful to use in AutoCAD while I love using them in Inventor.

 

Then the problem in AutoCAD is once you create your solid from the 2D (sketch in Inventor terms) the solid is divorced from the 2D.

 

If Autodesk's intention was to introduce parametric constraints to the AutoCAD users thinking that would help them make the transistion to the next-generation products - I think that was a big mistake. AutoCAD constraints are so clunky - they scare users off from what I can gather.

 

I thought this was an impressive use of constraints with 3D in AutoCAD, but unfortunately it was not recorded.

http://au.autodesk.com/?nd=class&session_id=9238

[tzframpton]

ReMark, thanks for the find.

 

JD, I think you are so right. Man.... Revit really did it right. I mean its just so beautiful how you can build 3D objects using parameters and reference planes. To have AutoCAD have similar procedures would be so fun. I guess it'll stay a dream.

 

I did find that you cannot apply a parameter to any 3D object in the last ten minutes of fiddling with it. Such a downfall... I bet Autodesk eventually deploys it. I know it already exists in AutoCAD MEP but is far inferior to Revit's interface. Like, not even in the same universe when compared, kind of inferior. I could only imagine how intricate and great Inventor is now that I'm getting familiar with Revit's parametric interface.

 

Thanks for the discussion gentlemen.

[shettyvip7687]

hi..

autocad parametric constraints can be used in 3d..they generate good models too.:)convert a assembled model into block and use parameters and actions in block editer...try it its very interesting.

[tzframpton]

I did try it, or so I thought. Can you elaborate a bit more on how this is accomplished? Thanks for the post.

[scj]

Have a look at HOFCADs ideas:

http://www.cadtutor.net/forum/showthread.php?24797-Animation-Simulation-LIsp&highlight=hofcad

And - yes, you can use it for 3D-simulation too - make a skeleton sketch (lines, arcs ...) for the moving parts and connect them as blocks to the skeleton.

Regards

Jochen

[khama]

I abandoned constraints in Autocad 2011 and have been using the old method for solids using point filters. Then I am in control of the outcome.

[JD Mather]

Why are you not in control of the outcome using Constraints?

You should have far far far more control with Constraints.

[khama]

Why are you not in control of the outcome using Constraints?

You should have far far far more control with Constraints.

 

Constraints don't work properly in Autocad. Point filters are precise constraints on which ever axis you choose and I choose which axis is to be constrained and what point I want it at. With constraints in Autocad if you choose the wrong type undesirable results occur. So how is that FAR FAR more control?

 

Sounds like you have too much faith in Parametric software which limits you so much. I like to be free of parametric limitations. Each their own I suppose.

[ReMark]

I thought one of the reasons to utilize constraints was to limit the geometry so as to avoid unintended consequences (i.e. - precise control).

[khama]

have you guys explored point filters? They ROCK !! Faster more accurate and as precise as you make them. Point filters available are .x .y .z .xy .xz .yz double moves and you pick the point at which it moves to. Easy to use as well. start a command pick the point you want to move from enter .x (or whatever) during the command and pick the point you want it to go to and wellah done. It takes seconds..

[ReMark]

Yeah, been there, pointed that. No one is arguing that point filters don't have their uses just as constraints do. Use the right tool for the right job.

[khama]

OK whatever, keep using constraints and I will keep using point filters and I would be finished way before you. Productivity is king..

[ReMark]

Maybe you just don't understand when constraints are warranted. Fine by me.

 

Now if you said constraints in plain AutoCAD don't match up with those in Inventor then I'd have to agree wholeheartedly with you.

[khama]

i understand when they are required fully. Just useless junk and not needed.

[ReMark]

Your confidence in point filters is inspiring.

 

Maybe you could educate me then how you would accomplish a point-to-object coincident constraint using point filters instead. Take your time. I'll wait.

 

As Brian Benton of AUGI points out in his three part series on AutoCAD and Constraints...."It’s one thing to know that commands and features exist inside AutoCAD or any other program, but it’s a completely different thing to know how and when to use them. Knowing "why" doesn’t hurt, either."

[SLW210]

Productivity is king..

 

Wrong, Wrong, Wrong!!!

 

Accuracy and properly done drawings that are legible and easily interpreted and used by others is KING.

Edited February 24, 2012 by SLW210

[JD Mather]

I have always found that those who do the best quality work are also generally the fastest (and nearly always the fastest if you consider re-work).

In my opinion (based on years of experience) true productivity follows quality.

Those who really know how to use the tools, when to use particular "power user" tools can be astonishingly fast.

[ReMark]

I once worked with a guy on the "board" who was astonishingly fast on the first go around until you saw all the mistakes he made. Unfortunately he mistook speed for quality. LoL