This tutorial/exercise looks at tweaking some of the density fractal values applied to an Altocumulus layer. In order to make use of this exercise you'll need to download the zip files from the links on this page. These contain the .tgd and .tgc files needed to reproduce the exercise. Since these files are XML type files and readable on their own, you might want to open them up as text files and look them over.
Next question. Why should you bother? Well... This exercise starts with a variant of the 'Wall of Clouds' technique found here. It starts from something like this:
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and by changing values finds something like this: |
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January 17, 2007
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Using this .tgd file we start with this image. You'll need to go to the Heightfield Generate panel and click the 'Generate Now' button so you can see something other than a flat terrain. Next, you'll need to focus on the Atmospere node in the node panel. Hint: Left click the Atmosphere button in the node overview panel. Once you've done that, delete the three atmosphere nodes in the panel (Atmosphere 01, Altocumulus layer 01 and density Fractal 01. Finally, go to the File menu and do an 'Insert Clip File' with this .tgc file.
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In the Density Fractal window, choose the Density panel. If you set the Contrast value to the values on the left, your quick render should look like the images on the left.
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If you've been following along, you may have noticed the Contrast slider goes from 0 to 1. Now, if you promise never to reveal this to the uninitiated, here's a secret of the Terragen Masters: you can enter values outside the range generated by the sliders. So, by entering values directly in the Contrast field, we get the images to the left. Useful if you're trying to achieve stormy rain clouds.
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Next, let's see what happens when we change the 'Coverage adjust' slider. Before doing this, we'll delete the atmosphere nodes and insert replacements from this .tgc clip file. To the left, you'll see the results of changing the coverage.
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Finally, using this .tgc clip file, let's take a brief look at the effect of the 'Roughness' slider. We'll set the Roughness to 1 (from ~4.8) and redo our Contrast variations. The result is on the left. So... What's the exercise? Nothing particularly difficult, just try varying the values we've looked at in different ways. Try different Roughness values. Try varying the Coverage on different Contrast values. |
