HF Fractal Detail Equivalent

[ejgodwin]

In the heightfield shader, there's a tab for fractal detail, which is great for adding realism to an imported terrain. But I'd like to have more control over it, such as min/max altitude and slope, etc.

So I used a power fractal shader with an attached distribution shader, but the default settings are far too jagged. What settings would be roughly equivalent to the HF fractal?

Thanks!

[j meyer]

If my memory is correct the "Fractal Warp" shader is the one to use
for that purpose.

[ejgodwin]

If my memory is correct the "Fractal Warp" shader is the one to use
for that purpose.

I'll give it a try, thanks!

[ejgodwin]

Tried two different kinds of shaders, warp & alpine, but couldn't get them to do what I want. Though the following thread is a while back: http://www.planetside.co.uk/forums/index.php/topic,4831.msg50437.html#msg50437,  it mentions that there's no equivalent shader to the Fractal Detail tab.

[jo]

Hi,

I had a look at the code for the Heightfield shader and what it's doing to add the extra fractal detail is quite involved. As mentioned in that other thread it would be very difficult to mimic the what the shader does. I think it would be a case of experimenting with the other nodes until you got something you liked.

Regards,

Jo

[Matt]

The Fractal Warp Shader works very similarly to the fractal detail in the Heightfield Shader. It's new in TG3. It's even more powerful than the heightfield's built-in fractal detail because it can be masked.

It works by warping all the shaders above it. TG3's default scene uses it.

Matt

[ejgodwin]

The Fractal Warp Shader ... more powerful than the heightfield's built-in fractal detail because it can be masked.

That's sort of the point - to be able to control where to add the detail. I reduced the scale on the Alpine Fractal  and got something a bit closer to what I wanted, but not exactly.

Does the HF Fractal Detail computation take the slope of the terrain into account? For example, flat plains would be smoother, but the fractal would be more pronounced in mountains or canyons. Or perhaps there's a way to pipe the computed terrain into a fractal shader and use slope as a multiplier.

[Matt]

No it doesn't consider the slope, but by the very nature of warping the incoming shader it appears that steeper parts of the shader are more affected by the warp. Flat terrain looks like the warp has no effect, because it's warping "nothing".

Matt

[Dune]

So in fact it works kind of the same as a warp shader plus vector displacement shader plus PF? Or is there a special feature inside that sets it apart?

And the variation, is that similar to the power fractal noise variation? If the working are the same, the mentioned combination would give you more stuff to adjust, that's what I would like to know.

[Matt]

It is a completely different algorithm which isn't possible with any of the other shaders.

Matt

[Dune]

Thanks, Matt. Good to know I have to use them by their own merits (if that's how you say that).