Creating "Spires" and Heavy Displacement (Mojo-esque)

[Volker Harun]

I understand ...

For the blending ... last shader before the displacement-shader is a multiply scalar - connected with a power fractal.

Look at the attached clip.

[Volker Harun]

I am using this clipfile now ... rendering without GI and detail 0.8 ... no cut offs yet ,-)

[efflux]

I'm still struggling here. I looked at your file but still can't work out how to achieve what I want.

As you can see you have partly recreated a kind of fake stones shader with the voronoi by doing that clamping but the fake stones shader does mask itself the way I want but I can't achieve that part.

I EDITED THIS MESSAGE

It now reads fake stones instead of stone roses. This is what I originally mean't. I don't want to confuse anyone else reading this.

[efflux]

Your way of getting back to 0 to 1 is cool. That's useful.

[Volker Harun]

Yep, I used your setup - I guess, that I missed your point.
I thought that you needed a blender between 'functions' and 'displacement-shader'.

[efflux]

It's hard for me to explain. I'm not a mathematician but that's not really important with this particular problem. Since I know Mojo I am comparing to that. Here are some screenshots from an old tutorial that spawned all those Mojo tower type planets. If we can crack this, it's a major step but we must be able to because the fake stones actually does something similar:



In this image you see a masking going on. It goes in this order from left to right - World Position / Surface Pos / Surface Pos with displacement / Undisplaced Surface Pos.

Mojo simply has these option to choose from similar to how you can choose Final normal, Terrain normal and Planet/Object normal when you choose how to constrain slopes.

So you see we need an undisplaced surface position mask.

[Volker Harun]

Which is a problem.

The first scene I uploaded has a fractal mask (black and white) for the displacements (spikes).
Of course, you can plug this as a fractal breakup into a surface shader. But the 'compute terrain' seems to make an offset. Surface shader and displacement do not match.

At least you need a 'colour adjust shader' to increase the contrast of the mask. And maybe playing with the patch size of the compute normal will help.

I'll try this sonn ... errr ... now ,-)

[efflux]

Yes, the colour adjust shader comes in useful in these circumstances. I have been using it.

[efflux]

I'm just thinking aloud here. Hard to explain everything. The clamping is an important part and your way to get back to 0 is cool. We have whole flat areas with value 0. This is the undisplaced surface. We need that as a blending mask if you see the point.

[Volker Harun]

1. Use 'Get position in geometry' - this makes it independent from Y (height) or multiply the 'get position with a constant vector (1|0|1).

2. Make the clamp close, i.e. 0.65 and 0.70

3. delete my blending fractal-stuff right before the displacement node.

4. Use that 'Divide to get 0 to 1'-node for the displacement shader and as mask for the stoneroses' surfaces.

A file is attached. One point that does not make sense is that the surface shaders are stuck to the spikes, the displacement goes wild, but.

[efflux]

AWESOME. It's solved. Thanks.



The possibilities this unfolds are tremendous.
I've tweaked around with your file. I'll post a result test render in a few minute so you can see. Then I'll build another file with the pure basics of how it works and post the tgc.

[Volker Harun]

I attached a rough working scene, too. Bet yours will be better ,-)

Two issues:
1. The bottom colours blend to the ground - this could be handy but needs tuning.
2. The displacement seems to have below zero values. Look at the bottom left, where cuts are in the ground.

Thanks to your immense elan, input and output. It was fun!
Good night,
Volker

[Volker Harun]

That negative holes are my fault - forget it ,-)

[efflux]

OK Volker. My render is quite similar to yours but with huge bulbous overhangs. I'll start afresh with something more appropriate as an example of the extremes possible here and post the tgd. I'm not using voronoi for the spires. I think perlin is better because it's smooth.

He he, this is going to shock the Mojo users for sure   

[efflux]

I messed around with various versions then decided on this one:



We could do with making the mask less sharp at the edges. In Mojo that is easy but not so easy in TG2.

It seems like there are a few small artifact problems but it's pretty clean considering the extremes.

The disabled fractal is for whatever else anybody wants to do with terrain. I didn't leave it with no other input. It makes it a bit clearer. I was just concentrating on the spires.