Does the automatic clipping plane calculation work?

[Joran]

Hello,

Does this command work?

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.

[farshizzo]

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.

[Joran]

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.

[Joran]

Hello,

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

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.

[farshizzo]

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.