Patchy surface layers

Started by kevnar, August 02, 2009, 01:41:12 PM

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kevnar

I'm trying to figure out how to lay down surface layers in distinctive patches without using a painted shader. When you reduce the coverage below 100%, to 50% say, how do you get the borders of the surfaced areas to look well-defined and not so fuzzy/blurry? Currently it looks more like the surface is painted everywhere except painted with 50% translucency instead of 50% coverage.

I've seen people do this in terragen. I hope someone can explain this in a way that's easy for a newb like me to understand. Thanks in advance.

This is what I want:


This what I'm getting:

Henry Blewer

I use the scale and lead in scale to make the size areas I need. Altitude and slope constraints also help. The power fractal is a way of general distribution. By itself it does not have much control. Maybe 70% of the posts here have to do with what you are asking.
http://flickr.com/photos/njeneb/
Forget Tuesday; It's just Monday spelled with a T

Tangled-Universe

Quote from: kevnar on August 02, 2009, 01:41:12 PM
I'm trying to figure out how to lay down surface layers in distinctive patches without using a painted shader. When you reduce the coverage below 100%, to 50% say, how do you get the borders of the surfaced areas to look well-defined and not so fuzzy/blurry? Currently it looks more like the surface is painted everywhere except painted with 50% translucency instead of 50% coverage.

I've seen people do this in terragen. I hope someone can explain this in a way that's easy for a newb like me to understand. Thanks in advance.

This is what I want:


This what I'm getting:

to get well defined patches you need to play with the fractal contrast values. Increasing it makes the edges of the features harder. Very high contrasted fractals create brighter fractal features, up to almost 100% pure black and white.
For starters I'd set your contrast to 10, offset to -4 and noise to 0. Then set all the 3 fractal scales to about the same value. Now you should have contrasted bright patches all over the place.
From there you can start finetuning.

Cheers,
Martin

dandelO

'Colour offset'.

That's your chappie, Martin is correct with the contrast details, aswell.
You want to reduce the 'colour offset' in the fractal(if you're using only 'high colour', raise it if you're using 'low colour', it balances the high/low distribution. If you're using both high/low colours, it describes how dominant each colour is.) to make less coverage of a certain surface, keep your surface layer at '1' coverage and reduce the colour offset in the fractal to reduce the amount of 'colour-spread' being applied.

The power fractal can also wash your dishes, if you ask it nicely, it can do anything, it's a real smart arse. ;)

Just negate the offset to reduce high colour distribution, raise it to reduce low colour distribution. Keep your parent surface layer at coverage='1'.