Barren World Tutorial

Started by nvseal, November 15, 2007, 02:17:20 PM

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nvseal

Barren World Tutorial

Being that I have been asked several times to create some kind of tutorial to help explain my planet renders, I've decided to use the "Barren World" render to create one. No, it is not as good as Volker's fantastic tutorial but hopefully someone will find this useful  :P. I have not looked back over the tutorial completely so if you can't understand something then just ask me. I am also including the tgd of the finished file to help.

1.   We are going to begin with the surfacing. Create a power fractal shader. This shader is going to serve as a base layer for the planet. Set the scales as follows: Feature scale – 2e+006; Lead-scale – 1000; Smallest-scale – 0.1. Change the high-color to the following: 101, 67, 49. Change to the low-color to black (0, 0, 0). Leave the color contrast, offset, and roughness in the default settings. Displacement should be unchecked. Change the noise flavour to Perlin billows. Warp should be unchecked. Try a quick test render (See Image_1.jpg). It doesn't look great, but we do have a nice contrast that we can build on.

2.   Time to add some more color. Because the first layer is so dark, let's make the next layer brighter. Create a power fractal shader. When surfacing planets from this altitude don't be afraid of large feature scale values. Set the scales to the following: Feature-scale – 3e+006; Lead-in-scale – 1000; Smallest-scale – 0.1. Change the high color RGB value to 134, 101, 81. Leave the contrast, offset, and roughness in the default setting. Displacement should be unchecked as before. Change the noise function to perlin ridges. Mixing perlin types is always a good idea because it adds a nice subtle contrast in the planet coloring. No warp. Again, try a test render(See Image_2.jpg).  Much better than the first test but still not ready to ship.

3.   Time to make another power fractal. I'm going to use this fractal to try to unify the two previous layers. The test render should help explain what I mean. Set the power fractal scale values as follows: Feature-scale – 4e+006; Lead-in-scale – 1e+006; Smallest-scale – 0.1. For this shader, I want the color to be bright and more saturated than the previous colors. Set the high color values to 165, 110, 66. Change the contrast to 0.3125 (you could probably use 0.3, I just usually use the sliders), the offset to -0.5, and the roughness to 2.5. We still don't need displacement so uncheck it. Leave the noise function as perlin but change the buoyancy from variation to 0. Check the warp option. Leave the warp amount at 0.5 and check the "Less warp at feature scale." Try another test render (See Image_3.jpg). . Not much difference can be seen but there is a subtle color layered over the other layers.

4.   The planet looks okay right now, but it still needs something to add some contrast so planet doesn't look so boring. Create another power fractal shader. Set the power fractal scale values as follows: Feature-scale – 3e+006; Lead-in-scale – 1e+006; Smallest-scale – 0.5 (the 0.5 is probably not a necessary value to change). For this shader, I want the color to be bright, like the previous shader, but I also want it to stand out. Set the high color values to 221, 141, 94. Change the contrast to 0.5, the offset to -0.4, and the roughness to 1.8 (the low roughness allows the colors to bleed into the other layers more naturally). We still don't need displacement so uncheck it. Change the noise to perlin billows. No warp is needed. Try another test render (See Image_4.jpg). This is much much better.

5.   Just for fun, I want to warp the billows a little bit. Create a warp shader, a redirect shader, and a power fractal shader. Attach the previous power fractal to the warp shader's "shader" input. Attach the redirect shader output the warp shader's "warper" input. Attach the power fractal to the "X" and "Z" inputs of the redirect shader. In the power fractal shader, change the Feature-scale to 553397 (or 550000), change the Lead-in-scale to 409600, and Smallest-scale to 0.1. Change the displacement to 1e+006. Leave everything else alone. Run a test render to see the change (See Image_5.jpg). .

We are done with the surfacing; now we need to add displacement.

1.   Create a power fractal shader. Change the scales to the following: Feature-scale – 1000; Lead-in-scale – 100000; Smallest-scale – 0.1. Change the displacement to 2000. Leave everything else alone.

2.   Now create another power factal shader. Change the scales to the following: Feature-scale – 5000; Lead-in-scale – 316406 (or 310000, it doesn't matter too much,  just make it different from the first fractal); Smallest-scale – 0.1. Change the displacement to 1000. Change the noise to perlin billows and the buoyance to 0. Leave everything alone.

3.   Time to make a blend shader. Create a new power fractal shader. Change the scales to the following: Feature-scale – 3e+006; Lead-in-scale – 200000; Smallest-scale – 10000. Set the color contrast to 0.2, the offset at 0, and the roughness at 5. Uncheck the displacement. Leave everything else in the default settings. If you want you can name the power fractal something useful like "Blending Shader."

4.   Now attach the Blending shader to the "Blending Shader" inputs of the two terrain fractals and run a test render. It looks basically done except for the atmosphere.

5.   I also added a strata and outcrops shader before connecting the terrain to the computes terrain node; but it isn't necessary.

Run a test render to see the difference with the displacement added (See Image_6.jpg). .For the atmosphere, you can do what ever you wish. In my scene I set the following values:

Haze density = 1
Bluesky density = 1
Haze glow = 4
Bluesky glow = 1
Haze horizon color = 145, 108, 86
Bluesky horizon color = 243, 243, 243
Bluesky density color = 185, 117, 78

Run a test render to see it all together (See Final.jpg, the final render of mine is in the planetside image section). And there you have it. I hope someone can find this helpful. I have also included the finished tgd for your reference. Have fun.

dhavalmistry

Excellent....thank you very much!;D
"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

rcallicotte

#2
Oh, you are so awesome.  Thank you.

This is going into my collection of tutorials.
So this is Disney World.  Can we live here?

Will

The world is round... so you have to use spherical projection.

chefc

Chef C  ;)

Serving the masses  8)

Arandil


Will

Think I already asked this (and its off topic) but what star map do you use?
The world is round... so you have to use spherical projection.

Tangled-Universe

I'm not a real 'planet-guy' so to say, but this is really really great!
Very generous to share your techniques with us in this detail :)
This one's being bookmarked as well, thank you!

Martin

nvseal

Quote from: Will on November 19, 2007, 04:40:35 PM
Think I already asked this (and its off topic) but what star map do you use?

I used one moodflow gave me I think.

rcallicotte

@nvseal - Is it okay to ask you questions about the various steps to better understand what you know about these things that I don't?  If this is a good forum for it, I'll start tomorrow or Wednesday with some serious considerations about your logic. 

Thanks again for this tutorial.  It's great to get a chance to understand how you've done these marvelous planets.
So this is Disney World.  Can we live here?

nvseal

Sure, I'll try to do my best to answer any questions you might have.

rcallicotte

#11
I only have a couple of questions for right now.

1.  In the Power fractal shader v3 08 that goes into the Warp Shader, what was the deciding factor for having such a large (1e+006) Displacement Amplitude?  It's going X and Z directions, but I'm wondering how you came to this number in light of your using 1e+006 as a seeming scale throughout.  For example, your first three PFSs are 1e+006 apart in your Shaders' Feature Scales.

2.  I'm not sure I understand the Warp Shader very well, but can you explain what the PFS v3.09 is doing in the Shader node of the Warp Shader and give me some logic around your decisions with these scale values?

I realize these are sort of picky questions, but feel free to explain at whatever level you are comfortable divulging.  I find this as fascinating as understanding Volker's texture descriptions.
So this is Disney World.  Can we live here?

nvseal

#12
1. Do you mean the warp shader that goes into the redirect shader then the warp shader? If so, the large displacement simply makes the warping of the surface more pronounced. When I turn my laptop back on later I will upload an image which clearly shows the effect of the redirect shader. As for the 1e+006 being used throughout some of the other fractals, the main reason is that it looks pretty decent. The better reason is that it creates a feature scale that is large enough to maintain a generally non-repeating fractal but at the same time maintain some smaller, repeating patterns. If you get what I mean by that...

2. Basically, the PFS going into the warp shader's Shader node isn't doing anything besides providing the fractal. Without an input for the warp shader's Warp node it is as if only the power fractal was there (try unconnecting the warp node to see what I mean). This being the case, my decisions around the scale values are just like the other surfacing shaders. The things I usually consider are: what color is the surface and how does the scale effect it (i.e. a bright color may not need as much offset of feature scale as a dark color might), what is the color roughness, what is the color contrast, what is the color offset, what is the noise type, what is the noise variation and what is the buotancy from variation.

I hope this asnwers your questions to some degree.  ;D

Edit: Here is the image.

rcallicotte

This helpful to understand what you're thinking and it's opening up a new way for me to understand this product.  It's funny how the simplest things can seem so complicated until I see how someone has done them. 

Thanks.
So this is Disney World.  Can we live here?

Seth

how could i miss this tutorial ?!!!