WorldViz User Forum - Does the automatic clipping plane calculation work?

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- - Does the automatic clipping plane calculation work? (https://forum.worldviz.com/showthread.php?t=2134)

Does the automatic clipping plane calculation work?

Hello,

Does this command work?

Code:

window.clip(viz.AUTO_COMPUTE)

I have tried it, but when I print the clipping planes of the window (in the onUpdate) they do not seem to be automatically updated.

Greetings, Joran.

Yes, it works. The problem is that when automatic clip plane computation is enabled, the window will return static values for near/far, since the actual clip planes values are not known until culling is performed.

Hello,

I would already be happy to know the values of the previous render step.

But the other thing is that I don't see it working. In my application I still see the z-fighting when automatic clip calculation is turned on, while it disappears if I calculate the clipping planes manually. But maybe I have some object in my scene that is way of the rest of the model that influences the automatic clipping plane calculation. I will investigate further.

Greetings, Joran.

Hello,

I have made a sample script that shows the problem (And I think I may have found a bug).

Code:

import viz



viz.go()



boxbig = viz.add('box.wrl', scale=(2000, 1, 2000))

boxsmall = boxbig.copy()

boxsmall.setScale(100, 1, 100)

boxsmall.setPosition(0, 0.001, 0)

boxsmall.color(viz.GREEN)



viz.MainView.setEuler(0, 87, 0)

viz.MainView.setPosition(0, 3000, 0)

boxsmall.addAction(vizact.spin(0, 1, 0, 20))



#texquad = viz.addTexQuad(viz.ORTHO)

#texquad.setScale(100, 100)

texquad = viz.addTexQuad(viz.SCREEN)



vizact.onkeydown(' ', texquad.visible, viz.TOGGLE)

It looks like when I add something to viz.SCREEN (or viz.ORTHO) that this will be used when calculating the clipping planes. In the example script when you run it, you should see a small green square that z-fights with the red square. When you press the spacebar, all is fine again, since this removes the texture quad from viz.ORTHO or viz.SCREEN.

What do you think? Have I found something? I am still using Vizard 3.12.0004 and not 3.14.0004.

And it looks like that the automatic computing of the clipping planes is on by default.

Greetings, Joran.

Thanks for the sample script. This looks like a bug in the OSG library. I have back ported a fix from the current version of OSG to our version and it seems to resolve the issue. I will email you the modified file so you don't have to wait for the next release.