topic Re: create smooth curved solid 3D in AUTOCAD in AutoCAD Forum

create smooth curved solid 3D in AUTOCAD

Anonymous — Mon, 27 Jun 2016 19:19:57 GMT

I have the problem in AUTOCAD how to create curve in 3D to make a solid 3D curved transition

Re: create smooth curved solid 3D in AUTOCAD

john.vellek — Mon, 27 Jun 2016 19:22:03 GMT

Hi @Anonymous,

Can you attach a sample or illustration of what you are trying to build? I look forward to helping you.

Re: create smooth curved solid 3D in AUTOCAD

rkmcswain — Mon, 27 Jun 2016 19:25:01 GMT

Does this help?

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Tue, 28 Jun 2016 11:16:07 GMT

the follow attached contain my model,I want to connect this two parts by a curved 3D, But the broblem is the difference in elevation between two parts which arc can not be created in 3D

https://drive.google.com/open?id=0B3t03lOcC-CSWUlmb0xaUnNTSEE

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Tue, 28 Jun 2016 11:30:49 GMT

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Tue, 28 Jun 2016 11:29:34 GMT

thanks, Your video is benefit but I dont know how much the rotational angle it is irregular shape

Re: create smooth curved solid 3D in AUTOCAD

john.vellek — Tue, 28 Jun 2016 19:17:03 GMT

Hi @Anonymous,

I apologize for not getting back to you earlier on this. I am still playing with this issue and making a bit of progress. Building a 3D arc has always been a bit tricky. Typically, one would create a UCS based upon three points but perhaps due to my lack of expertise this wasn't working very well for me.

I had better luck creating a solid between the two structures and then creating a 3P cylinder attach to the two corners that are at different heights. Then I used a Subtract so that only the concave solid remains. It is still not perfect so I haven't attached it yet but I am going to give it another attempt.

Thanks for your patience.

Re: create smooth curved solid 3D in AUTOCAD

Michiel.Valcke — Wed, 29 Jun 2016 06:54:10 GMT

I added two closed 3dpolylines (3DPOLY) to the face of each end and then used the LOFT command to connect them. You can choose a guiding line if you want to accentuate a certain shape or curve. You can also play with the vertex to change the smoothness and the settings of the curve.

If you make a 3D Arc first you can use that as a guide so the solid will follow the shape and angle of that arc.

I hope this helps

Re: create smooth curved solid 3D in AUTOCAD

SEANT61 — Wed, 29 Jun 2016 08:05:41 GMT

Here's another method of creating that transition.

Extract the edges of the two rectangular ducts. Create a Blend curve between corresponding edges. Loft surfaces for each set of Blend curves.

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Wed, 29 Jun 2016 11:00:45 GMT

i is a good idea

thanks

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Wed, 29 Jun 2016 11:04:30 GMT

thanks, but how to create blend curve in 3D

Re: create smooth curved solid 3D in AUTOCAD

Michiel.Valcke — Wed, 29 Jun 2016 11:29:27 GMT

I'm not really sure what you mean by that.

But can the command BLEND help you?

you make two polylines along your duct and then use the blend command to make a spline in between them that is adjustable.

Re: create smooth curved solid 3D in AUTOCAD

Michiel.Valcke — Wed, 29 Jun 2016 11:42:08 GMT

Is it something like this that you want to do?

Re: create smooth curved solid 3D in AUTOCAD

john.vellek — Wed, 29 Jun 2016 15:25:12 GMT

HI @Anonymous,

I am checking back to see if my post or others helped you with your problem.
Please add a post with your results so other Forum users can benefit.

Please select the Accept as Solution button if a post or posts fully solved your issue or answered your question.

Re: create smooth curved solid 3D in AUTOCAD

elshawadfy — Wed, 29 Jun 2016 21:39:12 GMT

Hi @Anonymous,

You can also copy both rods first and -

1- convert both geometries to NURBS (CONVTONURBS)

2- Delete the end caps surfaces where you want to connect your geometries..

3- Use SURFBLEND to connect both ends:

- CH (for chain) > select first rectangle > enter

- CH (for chain) > select second rectangle > enter

- You'll see 2 small icons at both ends, click on each and change the continuity to curvature G2.. then Enter..

4- You can now copy the newly created element to it's original place.. and delete unnecessary elements..

Regards..

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Sat, 02 Jul 2016 10:47:02 GMT

when I want to create loft using guide it does not work (for arc it worked), but in my case I created curve using coordinate by Spline, please see attached

https://drive.google.com/open?id=0B3t03lOcC-CSTXJGb3MzNXFmUzQ

Re: create smooth curved solid 3D in AUTOCAD

SEANT61 — Sat, 02 Jul 2016 13:43:10 GMT

See the screencast below to see how I envisioned the ‘Blend Curve to Surface’ approach. The process is a variation, with essentially the same results, of the process demonstrated by elshawadfy.

The attached file has all of the surfaces lofted, plus that geometry unrolled if this is a ‘tin knocker’ project.

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Sat, 02 Jul 2016 13:55:21 GMT

this is surface (not Solid body) any way, I can generate loft for this case but if guide is curve (part of circle) but for attached profile I constructed using coordinate (may consists of some circles) it does not generate

Re: create smooth curved solid 3D in AUTOCAD

SEANT61 — Sat, 02 Jul 2016 14:20:24 GMT

@Anonymous wrote:
this is surface (not Solid body) any way, I can generate loft for this case but if guide is curve (part of circle) but for attached profile I constructed using coordinate (may consists of some circles) it does not generate

I'm having a bit of trouble understanding. The one part I did follow was that my assumptions were not correct.

Are you reverse engineering existing components - and trying to fabricate a connecting part?

Re: create smooth curved solid 3D in AUTOCAD

Anonymous — Sat, 02 Jul 2016 16:03:57 GMT

thanks, your method is quite good, but when I repeat same thing transition does not create (for Solid 3D), for transition design I used a function (x=ay^b), this produce arc composed more than one curve, finally I want to say transition using one curve (one radius) can be create using loft but for arc (composed multiple curve) can not be create but I do not why!!!, please guide me if Iam wrong