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I read up that issues sometimes occur with a too low start clipping distance, and since the model I'm working on is pretty huge, I set the start clipping to 1 blender unit. However, I noticed that the edges in edit mode became dashed after doing this:

dashed edges

However, from straight down instead of a grazing angle, it looks normal, even with the high start clipping:

top view with high clipping

And, just for comparison, here's what it looks like with a start clipping of 0.01:

normal clipping

I'm completely fine just using the lowered start clipping, since I can't see any artifacts, but I'm still curious as to why this happens?

markasoftware
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    related: http://blender.stackexchange.com/questions/1385/shadows-along-edges-of-mesh-in-3d-view-viewport-clipping –  Sep 20 '15 at 05:49

1 Answers1

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its because Graphic cards Render the depth to a 16 - 32 Bit Depth Buffer where the start Clipping is 0 and the end Clipping is the max Value. But that Depth Buffers are only 32 Bit and 1e-40 is equal to 2e-40 there because its rounded. And when that happens the Graphics card can't figure out whats in the front and whats behind. You can also see this if you add 2 Planes is the exact same spot and then color them differently. You can even experiment with the distance between that planes and the clipping.

HenrikD
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