Author Topic: fixing shear cuts  (Read 350 times)

Offline daudvyd

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fixing shear cuts
« on: November 13, 2018, 04:29:54 AM »
There are a few functions that can result in shear walls cut into the ground or shooting up from the ground that render badly. The polygons look like long thin lines. Is there any way correct these polygons and perturb them to appear more like a cliff face? See attachment for an example.

-d. vyd

Offline Dune

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Re: fixing shear cuts
« Reply #1 on: November 13, 2018, 05:47:43 AM »
This looks like a warped simple shape as mask, but without a degree of fuzzyness. If you set it to smooth step or bevel, you'll get rid of it.

Offline daudvyd

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Re: fixing shear cuts
« Reply #2 on: November 13, 2018, 11:37:57 AM »
The shear cliff faces are made--at least in part--by the "displacement offset" in the FRACTAL TERRAIN node. Adjusting the "edge width" of the SIMPLE SHAPE SHADER input changes the shape of the shear cliff somewhat but does not always eliminate it.

Smoothing settings in the Tweak Noise tab of the FRACTAL TERRAIN node do not seem to have an effect.

I'd welcome other suggestions.

Offline Hetzen

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Re: fixing shear cuts
« Reply #3 on: November 13, 2018, 11:54:25 AM »
If you give a displacement a hard edge you're going to get those artefacts. Ulco is right, put a bevel or smooth step on your Simple Shape and play with the width (in meters) even just a meter will lose those shear polygons.

If you're convinced that's not the problem, then post a .tgp.

Offline daudvyd

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Re: fixing shear cuts
« Reply #4 on: November 13, 2018, 04:28:50 PM »
Switching the edge width to meters from percent and setting edge widths of 125 to 300 meters makes a big difference. But there are still a few shear walls I can't seem to get rid of. TGD and image attached.

Offline Dune

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Re: fixing shear cuts
« Reply #5 on: November 13, 2018, 04:35:35 PM »
First of all, you've used final position for one of the SSS's, so that one won't participate in the fractal warp, hence a hard straight edge. Changed that. I've also taken out the edge colors and softened edges even more, but I don't know if this is what you need.

Offline daudvyd

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Re: fixing shear cuts
« Reply #6 on: November 13, 2018, 04:42:11 PM »
Thanks! I missed that one was set to "final position".

Offline daudvyd

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Re: fixing shear cuts
« Reply #7 on: November 13, 2018, 05:44:51 PM »
The part circled in blue in the attached image remains a problem. I'm wondering if the ADD and SUBTRACT nodes create these sharp transitions because the "edge width" of the SIMPLE SHAPE gets applied before the math function--not afterwards. 

Offline Dune

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Re: fixing shear cuts
« Reply #8 on: November 14, 2018, 06:26:39 AM »
There's one (second) that needed a smoother edge still. I hope this solves it.

Offline daudvyd

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Re: fixing shear cuts
« Reply #9 on: November 14, 2018, 08:02:50 AM »
Thanks Dune. Yes, that solves the problem. Originally, I expected even a single meter of edge to solve the issue. But, in some cases up to 600 meters was necessary. Does this mean that there are some general scaling or displacement issues in the file?

Offline Dune

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Re: fixing shear cuts
« Reply #10 on: November 14, 2018, 10:20:25 AM »
Your whole terrain areas was around 10.000m, so 225m is nothing compared to that, resulting in very straight sides. You could try using a percentage too, say 5%, just experiment.

Offline daudvyd

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Re: fixing shear cuts
« Reply #11 on: November 14, 2018, 10:47:21 AM »
OK. Thanks!