Smooth Circles

[John_M]

I am using VW 12.5 (Fundamentals, RenderWorks) and am having an issue with the creation of rods, in particular circular ones. Got a lot of help with this here previously and was going along fine until now, so I am back.

My procedure is as follows: I use the Ellipse Tool to create a circle. I then extrude the circle and export as an IGES file (because a second program that uses the rods requires IGES files).

I noticed recently after importing the IGES file into the second program that the circular cross section appears as a polygon approximation to a circle. I also downloaded a free IGES file viewer and confirmed the polygon structure there also.

So I went back to VW and discovered that the polygon structure happens when I do the Extrude command - what starts out as a perfectly smooth circle becomes a polygon approximation to a circle.

I'd appreciate if someone can shed some light on this. Are there options for doing the extrude that would avoid this?

Thanks.

[michaelk]

In Preferences, check in the 3D tab. (It might be a little different place in V12.5) Make sure 3D conversion res is set to very high.

hth

mk

[Rossford]

I think that is the correct answer. The conversion res converts a circle from 8 points (low) to 256 (high) and the choice is likely based on how smooth you want it to be, and file size that will result.

[John_M]

Okay, thanks. I'll check that out when I get back to work next week.

[John_M]

I set the 3D Conversion Res to Very High and it indeed did improve the smoothness of the circular cross section after extrusion.

I then extruded two circular geometries and exported each as IGES files. One geometry was created using Medium for 3D Conversion Res and the other using Very High. While the difference in VW was very noticeable, there was possibly a very slight difference when I viewed the two IGES files in external programs. They were so close it was hard to tell.

Was just wondering why the two cases would look so different in VW but not anywhere else. Is it some kind of display issue in VW?

Thanks again.