mountain lake scenario help

Started by pedro, September 20, 2010, 06:03:46 AM

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pedro

Hello all,
I'm new to Terragen, trying to create a mountain lake, but I want the sides of the lake to slope relatively gently into the lake, then rise quite abruptly into the surrounding mountains. I'm finding this effect very hard to achieve. Can someone give me some pointers as to how they'd achieve this? I've tried using a distance shader on the mountain fractal - not very effective, though it did at least make a roughly roundish lake which is what I wanted. I've also tried creating a heightfield in Photoshop (just a simple gradient from black in centre to white, then blended to environment when I apply). Again, not so good. Thanks in advance.

Henry Blewer

Use a Fractal Terrain generator. You'll want to change the Lead in scale from 20,000 o about 45,000. This should stretch the flatter areas out. This Displacement tab has a default displacement of 2000. Depending on how mountainous you need the Terrain, will determine how much to use. For rolling hills I use 1200 and reduce the roughness to about 0.4.
http://flickr.com/photos/njeneb/
Forget Tuesday; It's just Monday spelled with a T

pedro

Thanks, I'll try that. Can you explain exactly what "lead-in scale" does?

Henry Blewer

The lead-in scale is the large value for the fractal. The scale is how large the variation is. But the lead-in scale controls the distance between the noise. At least this is how I understand this to work.
The small scale controls how much detail is in the fractal variation.
http://flickr.com/photos/njeneb/
Forget Tuesday; It's just Monday spelled with a T

Hetzen

You might want to have a look at Gom's little gem here...

http://forums.planetside.co.uk/index.php?topic=4484.15

There's a nice little function that rolls off terrain at the coastal height, by his beach set of functions. It's a clip file rather than a scene, so open up a new scene and use file/insert clip file. Then plug into your planet.

It's worth trying to understand what he's done here, because he's made some very efficient node groupings, which he's taken the time to explain further on in the thread.

pedro

Thanks Hetzen. That's in the ballpark - though I need much bigger mountains than that! I'll have to fiddle around and see if this noise blending idea can get me close to what I want. This program is a revelation - but I have soooo much to learn... :(

Hetzen

I'd ditch the  :(, and replace it with "there's so much I can do" 8)