3 Points Perspective Drawing Using AutoCAD?

[SEANT]

. . . .

 

However, the one that I feel it's so difficult to me is to construct the ellipse-to-ellipse in isometric projection.

 

Can you explain at what point in the process did it break down. Or, better still, upload the drawing. That would be best at explaining the situation.

[huygen]

Can you explain at what point in the process did it break down. Or, better still, upload the drawing. That would be best at explaining the situation.

OK, please see the attached file below.

Isometric Ellipse.dwg

[SEANT]

I see you used an ellipse for the circles. That is good as long as you are only doing Isometric drawings. As you've already pointed out, the ellipse doesn't do so well when it comes to Perspective drawings.

 

As far as Ellipse-Polyline-Spline procedure, see attached.

 

One reminder set SPLINETYPE System Variable to 5 before PEDIT-SPLINE

IsoEllipsefromSpline.dwg

[huygen]

http://www.cadtutor.net/forum/showthread.php?60137-3-Points-Perspective-Drawing-Using-AutoCAD&p=420478&viewfull=1#post420478

 

SEANT, what is the next step after changing the polyline to spline?

[SEANT]

SEANT, what is the next step after changing the polyline to spline?

 

You tell me.

 

If you have to look back in this thread. See posts #9 and #12.

[huygen]

Model it in 3D form.

53_Bevel_Gear_Support_exercise.dwg

[SEANT]

Nicely done.

 

 

And, as has already been mentioned, this is the easier method of creating perspective drawings in AutoCAD.

 

 

 

See the returned drawing with the results of the FLATSHOTcommand.

53_Bevel_Gear_Return.dwg

[SEANT]

I'm working on a .NET routine that converts standard orthographic drawings to perspective drawings. It is currenly targeted at AutoCAD 2012, but should convert down to AutoCAD 2009 easy enough.

 

The project will soon be ready for public testing, and I'll be looking for some Beta Testers. Any interest?

 

By the way, huygen, here is that converted file.

Nozzle.zip

[huygen]

Hi SEANT, These are the files. Thank you Huygen

[lamensterms]

I just wanted to write and say thank you to SEANT for your detailed explanations regarding perspective drawing.

 

Some very handy techniques.

 

Thanks again.

[SEANT]

I just wanted to write and say thank you to SEANT for your detailed explanations regarding perspective drawing.

 

Some very handy techniques.

 

Thanks again.

 

You're welcome.

 

 

 

I'm working on a .NET routine that converts standard orthographic drawings to perspective drawings. It is currenly targeted at AutoCAD 2012, but should convert down to AutoCAD 2009 easy enough.

 

Here is the end result (2012 & 2013 only, though) - if anyone is interested.

http://apps.exchange.autodesk.com/ACD/Detail/Index?id=appstore.exchange.autodesk.com%3astsc_projective2d_2013%3aen

[lamensterms]

Great concept, I will check it out.

 

Regarding the spling drawing... I am having an issue creating a 2 degree spline. All the splines I draw end up being 3 degree (except the ones I create in your DWG). Just wondering if you could please let me know where I might be going wrong?

 

Thanks again.

[SEANT]

The Spline command has to switched to the alternate spline creation method. See command sequence below:

 

Command: _spline

Current settings: Method=Fit Knots=Chord

Specify first point or [Method/Knots/Object]: Method

Enter spline creation method [Fit/CV] : CV

Current settings: Method=CV Degree=3

Specify first point or [Method/Degree/Object]: Degree

Enter degree of spline : 2

Current settings: Method=CV Degree=2

Specify first point or [Method/Degree/Object]: 1,0

Enter next point: 1,1

Enter next point or [undo]: 0,1

[lamensterms]

It might be that the additional spline settings dont exist on 2010?

 

Here is what I get...

 

Command: _spline
Specify first point or [Object]:

 

No option to change the options.

 

Cheers.

[SEANT]

My memory had that feature for splines at 2009; it must have been 2011. If you still want to do the transformation by hand you may have to use the same technique I recommended to theOP. See the file in post #9. It shows how to create a degree 2 spline via the PEDIT’s Spline option.

 

 

 

The plugin I linked to above may not be compatible with 2010; I can’t tell for certain as I no longer have access to AutoCAD below 2012. If you can, let me know the situation. I may be able to recompile to get it working.

[lamensterms]

Hi again SeanT.

 

Thanks for getting back to me, I will certainly let you know how I go with the plug-in and 2010.

 

The splines... it was the instructions from post #9 which I followed to create them. 2 edge polyline > PE to spline > _spline to spline (object) > result (should be 2 degree spline). This does working in 2010 only in the DWG you provided. Any other attempt in any other DWG/session results in a 3 degree spline (with 4 vertexs rather than 3).

 

I will keep at it and see if i can find a way to achieve a 3 degree spline using the above method.

 

Cheers.

[SEANT]

Prior to the Pedit command, change the SPLINETYPE system variable to 5.

[lamensterms]

That did the trick. Magic.

 

Thanks a lot for that SeanT.

 

I tried to download your perspective routine - but I am getting an error about the .ZIP not being valid or something - I cannot open it.

 

Cheers.

[SEANT]

That’s weird. I can understand a problem when attempting to run the installer (MSI), because I may have targeted 2012 a bit too heavily, but I don’t know why there would be a problem with the ZIP. The Exchange-Apps team creates the final install (Zipped) package, but I've tested it and it worked well.

 

 

 

Perhaps your download became corrupted.

[lamensterms]

Yeah, I think my computer is having issues with the Autodesk Exchange site.

 

Ill try again when I get home.

 

Cheers.