I just want smooth curve display 1

[hudson888]

Under certain circumstances it has always been a bugbear that the curves will not render smoothly. For example sometimes you'll see a circle that displays as a hexagon, becoming octagonal as you zoom in and getting gradually smoother. This applies to curves in wireframe, and edges of solids whether shaded or wireframe to a greater or lesser extent. It also seems to be much worse when perspective is turned on.

Cases where it hurts are curves and splines touching or not quite touching by an extremely small amount say 0.001 mm and coming to an intersection or tangency. Sometimes you can measure distances and the answer is zero, but it displays a gap, and others it reports a gap but you can't see where to determine which two of three curves are correct. I find that you can often get an improvement using update display, and usually more so using regenerate work view. But often there seems to be no way or amount of zoom that will make the thing show me enough improvement to be meaningful. Even if you scale the objects by a factor of 1000 you may get the same thing. It only improves when you isolate geometry from the point of interest and then regenerate, so I assume it has something to do with the size of the feature relative to the model that you're displaying.

I guess a typical example would be a line or better still a spline intersecting an arc at a fairly oblique angle, say 10-15 degrees off being tangent. If you subdivide the spline to be two curves as it crosses the arc then reduce the length of one curve such that there is a tiny gap. Now zoom in a try to see whether the end of one or the other curve is touching the arc. I'm darned if I can tell. Worse at extreme zoom it won't let me select to measure I have to zoom out.

The other case is the engine animation. I have got quite good results but with the camera navigation turned on and perspective which seems to automatically engage itself, the wheels and other circular elements appear to have stepped edges even using high quality ray traced rendering. I have tried screwing down the line tolerance, hardware and software rendering and turning off all the accelerator modes under Visualization Performance settings, and I have used two machines with different certified graphics cards. It still won't come out as good as the static version of the same. As long as you don't use a trajectory curve this does not affect you.

We don't have all our licenses switched over to NX-5 so we can't test in later versions. I ran it in NX-3 initially and tried a brief test in NX-4 with no noticeable improvement. I think these two cases are manifestations of the same type of behavior, but would be happy to stand corrected. What if anything have I to change to force it to work, and is it any better in later versions?

Yours Hopefully

Hudson

 

[MSPBenson]

I think waht you are talking about is line anti-aliasing.
Try and change the visualization settings to see if it helps.

A top tip for rendering is that the rendered image will be as faceted as the view you have on your screen. The way to get this to update is to use Regenerate work from the view-operation menu.
This is better than using update display from the right click menu.

Make sure you do this when before rendering your animation. I can't remeber if it's critical that you do this when you set your key frames or if it's something that can be done just before you press the render button. Best thing is to experiment.

Hope that helps.


Mark Benson
Aerodynamic Model Designer

 

[MCGNX]

I've found doing a fit usually fixes that and the clipping

 

[hudson888]

Okay well I'll give the antialiasing another try I didn't think it did much earlier on, but it is relatively easy to test.

Yes if you run update display on a static shaded view you minimize the faceted appearance. I also found and mentioned that turning off perspective helps to improve your results. When you create an animation using a static viewpoint it appears that even though the parts are in motion the rendering stays at the same crispness. I should re-test, but I think the same may be said for turntable motion. Now despite my best efforts doing a navigated camera angle the faceting always reverts to a less acceptable level. I think it is because the view is being taken from different angles that it does so. Which is to say that if with perspective turned on and whenever you fit the view it appears by default to have a certain amount of faceting then that is what you'll get every time you change camera angles. Now in the static view this could be mitigated using update display, but under the navigated animation process there is no such opportunity to repeat that for each different camera angle. It only works for the simpler animations because there is essentially no change in the camera angle. What I need is some system setting that will increase the rendering accuracy such that I don't need to hit update display?

BTW I'm outputting tiff files from the animation which is how I can tell about these very fine points of the display.

Best regards

Hudson

 

[phillpd]

If you want to reduce the need for Update Display and Regenerate Work, from Visualization Preferences, change the Tolerance for Shaded Views on the Facets tab.

Specialty Engineered Automation (SEA)

http://www.sea4ug.com

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[hudson888]

Thanks Phil looks like the answer was there all the time. You can be sure I'll give the animation another try and let you know about the results.

Best Regards

Hudson

 

[MSPBenson]

Try doing an update display before you create each keyframe.
As I mentioned before I couldn't remeber if it was at that point that you needed to do it. Sounds like it is.
The only time you'll get lower quality results is if your camera zooms a long way into your your model without extra keyframes updating the display resolution as you go.
Even with higher faceting this can still be a problem.


Mark Benson
Aerodynamic Model Designer