SolidWorks import and tessellation

Started by Xidor, June 10, 2014, 09:42:07 PM

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Xidor

A few days ago I had tried to import a SolidWorks file in the new KS 5 as I was excited to read in the forums that the new version was able to smooth out the troublesome SolidWorks tessellation issue. But the default settings did not improve anything. The round parts still look jaggy.

I tried the nurbs setting on import to no better results either. So I was thinking it's not working for me.

Finally today, I tried again. This time I checked the "new importer" setting, plus cranked the slider all the way over to the right. To my surprise, one test file I imported has smooth curves and circles. I have another file that definitely imports poorly with round holes and round parts, I'll try that tomorrow and it's an assembly, so I hope the parts will import and retain the assembly tree.

So is this the way to import SolidWorks to get the smooth round parts? Use the new importer?

Thanks!

DriesV

#1
Cranking up the tesselation slider and NURBS are two very different things.
With higher tesselation you're importing a finer mesh. With NURBS you're not rendering a mesh at all.

If you want absolute 'CAD fidelity' (i.e. perfect rounds, smooth curvature) then NURBS is the way to go.

To import NURBS from SolidWorks models:
Use the beta importer and check 'Import NURBS data'.
After the import is finished, click the NURBS Mode button (ribbon bar) to start NURBS rendering.
You can toggle between NURBS and 'poly' mode anytime, using this button.

note: if all your rendering is going to be in NURBS mode, then you can set the tesselation slider really low (like 0.05). NURBS rendering will be the same quality, but file size of scenes will drop dramatically.

Dries

Xidor

Thanks for the reply. I understand the differences now in the tessellation when using the slider. I tried the tessellation setting all the way to 1.0 and the file is much larger. Then I tried the nurbs only setting. I didn't know about that nurbs button on the top menu bar. That was the key that I was missing!  :)

Both Beta imports have trade-offs. If I use the regular Beta import and crank the slider over, I get a huge file, but the parts are selectable. In other words, if I select a part, it highlights and I know it's selected.

If I use the Beta import and select nurbs data, the parts do not highlight if I click it most of the time. Other times the selection will highlight. It seems to be from being zoomed in too much. So I have to stay zoomed out.

Also, the hassle of the Beta import is that surfaces that I don't want are imported too. Those surfaces that were used to trim other surfaces. So the selection of those parts if they do not highlight is a real pain if I have to zoom in to select it. Also part names in the Scene parts list are no longer there.

I guess I'll experiment.

I've also noticed that on my 12 core machine at work, KS 5 can bog down and creep when I try to select item in the menus. This was a real surprise as the file worked fine when imported in KS 4. Maybe its a memory issue. If I quit and restart KS 5, it seems okay. A lot of little annoying little things with the good new stuff.

In regards to tessellation and mesh verses nurbs data. I didn't have a very clear understanding of that. I kinda knew always from back to the Hypershot days that models imported are converted to a mesh. And the mesh quality can be controlled either in SolidWorks and or with the slider on the import setting window. With SolidWorks being a nurbs modeller, it would make sense that the nurbs setting would create a perfect model in Keyshot. And it appears to. But with the associated unfortunate unwanted surfaces and lost names in the parts list. Can the Beta importer be improved?

Thanks again for the explanation. It was very helpful. If this is in the user manual, I'll look for it.



DriesV

#3
Quote from: Nelson Au on June 11, 2014, 09:40:16 AM
...
Also, the hassle of the Beta import is that surfaces that I don't want are imported too. Those surfaces that were used to trim other surfaces. So the selection of those parts if they do not highlight is a real pain if I have to zoom in to select it. Also part names in the Scene parts list are no longer there.
...

Well, you could always do a 'delete bodies' on those redundant surfaces in your SolidWorks models.
Then they shouldn't import when using the beta importer.
At least that's what I'm seeing here. :)

Dries

Xidor

I would be hesitant to delete bodies since that would remove the associated feature. Unless deleting bodies doesn't affect that. I'll keep it in mind.

DriesV

Quote from: Nelson Au on June 11, 2014, 09:22:21 PM
I would be hesitant to delete bodies since that would remove the associated feature. Unless deleting bodies doesn't affect that. I'll keep it in mind.

Deleting bodies as a last feature in the design tree won't ever mess up features that precede it. :)
Attached is a sample SW surface model of mine with a Delete Bodies feature at the end.
You can check the behavior inside SW or when importing into KS by suppressing/unsuppressing this feature.

Dries