Rotating Alpines

Started by WAS, May 25, 2018, 01:36:24 PM

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WAS

When you rotate a Alpine Fractal, it just transforms the shader on Z. For example 45, is about half, and 90 is a full "line" of alpine. Tried all world space and normal.

cyphyr

Are you expecting something different?
If you want to rotate about a vertical axis then use the Y input.
hope this helps :)
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WAS

#2
Quote from: cyphyr on May 26, 2018, 02:18:08 AM
Are you expecting something different?
If you want to rotate about a vertical axis then use the Y input.
hope this helps :)

I hope you paid attention to the screenshots. Rotating any axis, or all three, produces this effect. That's why I'm posting. The more you "rotate" the more it "transforms" and stretches. You cannot rotate them via the Transform shader it seems.

This same transform, on either rotation setting, or axis, will effect a PF correctly.

Basically I went to rotate a whole "continental" setup, and all was well, except the alpines, which turned into lines.

Kadri


Matt or Oshyan can explain it better and i might be wrong too maybe.
But like Richard said above this is normal i think. At least how Terragen works in general.

When you rotate the alpine globally there will be parts that look normal and parts that will look kinda stretched with rotating.
The nodes are acting kind of symetrically on the planet. When you rotate a part in the X axis there will be parts that look like they are rotate in the Y axis for example. Have a look and play with the example file below.

If you want to get the look you want globally you have to restrict some parts and use different rotation,transform etc. there probably.

Kadri

#4

If there is a slightly obvious look, stretch like in the alpine node,
you will see the same stretching with the other fractals too when you rotate them.
You can't see it in their default look because they have kinda the same noise in all axis's.

I am curious if i am right because this was how i saw it since years :)

Dune

It's just the way this thing is being calculated, different than a 'normal' PF.

cyphyr

Hmm works for me ... not sure why you're getting different results.

If you want to rotate the whole planet you could try inputting the lat and long you want to end up at the polls into the planet node (lat long at apex)
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WAS

Quote from: cyphyr on May 26, 2018, 11:41:03 AM
Hmm works for me ... not sure why you're getting different results.

If you want to rotate the whole planet you could try inputting the lat and long you want to end up at the polls into the planet node (lat long at apex)

I'm sure you're at 0,0,0. :P

So It is the displacement being rotated despite settings such as undisplaced normal before displacement is applied.



WAS

#8
Quote from: Kadri on May 26, 2018, 07:39:42 AM

Matt or Oshyan can explain it better and i might be wrong too maybe.
But like Richard said above this is normal i think. At least how Terragen works in general.

When you rotate the alpine globally there will be parts that look normal and parts that will look kinda stretched with rotating.
The nodes are acting kind of symetrically on the planet. When you rotate a part in the X axis there will be parts that look like they are rotate in the Y axis for example. Have a look and play with the example file below.

If you want to get the look you want globally you have to restrict some parts and use different rotation,transform etc. there probably.

Kinda upsetting. At every turn my ideas are shoved down the drain to limitations in TG that requires unnecessary work, especially globally on a rotating sphere at insane scales that are hard to work with being entirely human calculation and input since the sliders mainly work at a surface scale, or small scales.

Just discovered this morning after setting up 48 craters, that the crater smoothness doesn't work when actually incorporated into a terrain. It looks smooth in preview, and than in render just a ice-cream scoop hole. I didn't notice, but this is also seen in my Lunar Scene. Despite a very smooth and gradual crater in it's own preview window, the render looses seemingly everything but the pit, which has no smoothness.

Kadri

#9
Quote from: WASasquatch on May 26, 2018, 02:23:22 PM
...

Kinda upsetting. At every turn my ideas are shoved down the drain to limitations in TG that requires unnecessary work.
...

Believe me you can see posts like yours in every software.
It depends on what you want to do and if you are on the limits of the software etc.
You learn to get around those problems so much you can.
You know this most probably already but i just wanted to give kind of a little relief :)

WAS

Quote from: Kadri on May 26, 2018, 05:46:57 PM
Quote from: WASasquatch on May 26, 2018, 02:23:22 PM
...

Kinda upsetting. At every turn my ideas are shoved down the drain to limitations in TG that requires unnecessary work.
...

Believe me you can see posts like yours in every software.
It depends on what you want to do and if you are on the limits of the software etc.
You learn to get around those problems so much you can.
You know this most probably already but i just wanted to give kind of a little relief :)

That's true, though limitations I've ran into in programs like vue, c4d and Bryce usually tend to fall into more complex scenarios. not just wanting a mountain rotated at a certain position and turning to a line. Though I guess that's why heightmaps are the more popular option in TG... which is a bit depressing, making TG almost like a post-work option for textures and light.

Dune

Like I said, the alpine is most probably based on a vertically stretched fractal to facilitate calculation of the 'erosion', so it's just the way the alpine is built. If you stretch a normal PF and rotate on X/Z you get the same. A positive view upon this; using the colors of the displacement would perhaps yield a solution for your rotation wish.

cyphyr

Yes they are at 0,0,0.
It's all down to the discrepancy between XYZ and spherical mapping ... I think ... maybe.
All fractals seem to get stretched around the equator.
My somewhat "hacky" solution to this is to create whatever terrain/displacement I want at the poles (0,0,0), limit it with a simple shape shader, and then use a translate (rotate) node to move it to the equator or where ever you want it.
www.richardfraservfx.com
https://www.facebook.com/RichardFraserVFX/
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Ryzen 9 5950X OC@4Ghz, 64Gb (TG4 benchmark 4:13)

WAS

#13
Quote from: cyphyr on May 27, 2018, 01:41:01 AM
Yes they are at 0,0,0.
It's all down to the discrepancy between XYZ and spherical mapping ... I think ... maybe.
All fractals seem to get stretched around the equator.
My somewhat "hacky" solution to this is to create whatever terrain/displacement I want at the poles (0,0,0), limit it with a simple shape shader, and then use a translate (rotate) node to move it to the equator or where ever you want it.

That's a pretty good idea. What I had in mind though was using my background star thing, or none, hadn't decided, and a spinning globe rendered frame by frame, but yeah running into odd things like that to work around.

Quote from: Dune on May 27, 2018, 01:15:57 AM
Like I said, the alpine is most probably based on a vertically stretched fractal to facilitate calculation of the 'erosion', so it's just the way the alpine is built. If you stretch a normal PF and rotate on X/Z you get the same. A positive view upon this; using the colors of the displacement would perhaps yield a solution for your rotation wish.


I also thought of that, sorta rebuilding it based on colour and disp or something.

I don't think I could without animation but wonder if you could just "translate" the shaders and move the sun for a rotation planet.

Or, how big and smooth a SSS colour would need to be to mask in 6 sides to the sphere and rotations of the alpines to look gradual enough to be "blended realistically" before masking in alpines ot "mountainous" areas.