Mojotech (not only) for Bryce Users: Tutorial

Time To Get
Dressed!

The picture above shows our Tutorial Planet in all its fully dressed glory after we are finished with this page.
It's got Textures linked to most Materials, clouds in some areas and clear skies in others, and Ocean Waves which can only be made in the Function Graph Editor, or Pro UI. And it has a Sun, at last! It can now have Days and Nights and Seasons. Yours will probably have a Sun by default, if you are using version 1.1 or later.

Let us start with the sky. First, open the Sun Editor, click where it says "Light Source" and change the DDLB selection from "None" to "Sunlight", if it isn't selected already. You can now play with the "Orbit Position" control and also with "Orbit Position" and "Rotation Position" in the Time Editor to light the scene you are looking at. There is a difference between the two "Orbit Position" controls. In the Time Editor, it controls what appears to be the position of the Sun Orbit around the Planet (be aware that it's really the Planet which orbits the Sun...), in the Sun Editor it controls the position of the Sun on the apparent Orbit.
Next, let us create cloudy areas across our Planet. Once again, it's done with Textures, this time for the Cloud Colour and Density. Density at "0" means the sky is clear.

Open the Sky Editor and select "Add New Cloud Layer" from the top menu.

Click to expand the Control Stack for the New Cloud Layer. Call it "Clouds Added" and change the controls for Density and Colour from Widget to Texture, like you did for Result Scale when you made the Terrain. Set everything else as shown. Shadows disabled speeds up the render time.
Layer Height will depend on the mountain height. In Nature, there are low and high Cloud Layers. "Cirrus Clouds" range from 6000 to way above 10000 meters. "Cumulus Clouds" and "Stratus Clouds" start much lower. Cumulus Clouds can ride on the top of warm air pockets and rise quite high. If your mountains are very tall, move the clouds higher up. Have a look at John Spirko's Page about the scale of things in MojoWorld, including clouds. In MojoWorld, heights are in meters above the Planet Radius, not the Sea Level.
"Terrain Avoidance" specifies, in meters, how close your clouds are allowed to the Terrain below them.


Open the Texture Editors for Density and Colour and set the values shown as below. Don't forget to re-name everything, or those DDLBs will become very confusing. Having two complete Texture Trees available allows you to make an incredible variety of interesting clouds, using "tricks", like Domain Distortion and Blend options. But that's more stuff for side bars...



This setting creates clouds up to 40 km across. This will look about right for high altitude "Cirrostratus" Clouds.



This setting creates more cloudy and clearer areas up to 900km across.

Notice that I used the full output of the Fractal Function (which is always from -1 to 1) as an input into my clouds colour mapping, Using the curve, I discarded the very bottom end of it. I don't want totally black areas (the bottom end of the gradient) between my pink clouds. Feel free to do your own tweaking with an eye on the little preview windows.
For the Cloud Density, I dropped the Curve Output quite low all over to ask MojoWrld for a wispy transparent Stratus Cloud Layer, and again, I'm using the full range of the Fractal:

Expand the "Atmosphere" Control Stack and tweak the Colour Perspective settings until you like what you see. Colour Perspective works like in the Sky Lab in Bryce. It's the colour the Atmosphere changes to (from white, in our case) with increasing distance. The three settings are for the R, G and B values. Like with almost everything in MojoWorld, you can use textures or functions instead of solid colours... until render times go through the roof.

Now, open the Objects List, select "Ambient Light", open the Ambient Light Editor and set it up like in this illustration:

This tells MojoWorld to spill a small amount of blue-ish grey light into the shadows. The lighter the shade, the more light leaks into shadow areas. "Half Height" says that at a height of 30000 meters only half of the amount of ambient light should be present.

And that's Sky and Atmosphere finished!

Choose "Planet" from the Objects List and let us look at the Terrain Material Textures. We are leaving the Sand at its nice solid colour, but we are going to create patches of different shades of green for the vegetation, and something more complex for the rocks. You've done similar things several times now, so you won't need screen shots for everything, ok? If you get stuck, look at previous pages to refresh your memory about what the controls look like.

Let us do the Vegetation Texture first. In the Terrain Materials Editor, open the Control Stack for the Veg Material and change the Widget for "Diffuse" to a Texture. Click on the "t" icon to create a new Texture Node and name it "Veg Texture Node".
Create a Leaf, name it "Veg Texture Leaf" and click on "Output Control" in the Kickstand for the Leaf. In the Output Control Stack, open the Gradient Editor and create a Gradient from a deep olive colour to a rich dark green, not too far removed from each other in hue and value. We want this to be subtle, like small variations in Nature. There is no need to adjust the Curves.
Back in the Kickstand, click to edit the Monofractal. Set the Largest Feature to 8000 and Roughness to about 0.7, and you are done.

The Rocks are a little more complicated. I created two Material Leaves for them to make them a little more convincing.
In the Terrain Materials Editor, open the Control Stacks for the Rock Materials and change the Widgets for "Diffuse" to Textures. Click on the "t" icon to create new Texture Nodes and name them "Rocks 1 Texture Node" and "Rocks 2 Texture Node".
Create a Texture Leaf in Each Node and name the first one "Rocks 1 Texture". Leave the second one (in "Rocks 2 Texture Node") at the default "Texture Leaf". Following the same procedure as for the Vegetation Texture, create a Gradient for Rocks 1 Texture. Make it fairly complex - mine looks like this:

And now, a little trick: In the second Rocks Texture Node, where you have not named the Leaf yet, select "Rocks 1 Texture" from the DDLB of available leaves. Then, right-click (Windows) or control-click (Mac) on the T icon to the left of the DDLB and choose "Clone" from the Popup Menu which opens.

Change the name of the cloned Leaf to "Rocks 2 Texture".
Expand the Kickstand for the Leaf and change "World Position" to "Altitude". This applies the different colours of the Gradient in horizontal bands to the Cliffs and Rocks.
If you do a test render now, you'll see a nice blend between the two rock textures, but the horizontal bands are unnaturally straight. We are going to use Domain Distortion to scramble them a bit, like we did with the transition between Sand and Vegetation.
In the Kickstand, where the DDLB says "None" for Distortion, Select "MonoFractal" instead, and click to edit the Fractal. Set the Largest Feature to 5000 meters and Result Scale to 1500. Check back in the chapter about distorting the line between Sand and Weeds, it works the same way. Find a nice spot on the Planet, render and admire your work. When I did that, I decided to bring the Sand/Vegetation transition up to between 1000 and 1050 meters, in the Curve Editor for the blend between the two.

Finally, let us finish the water. Waves made with the Voronoi Basis look best, but Ocean waves usually come in elongated wave fronts, and there is no Basis Function available for this sort of a shape. We need to increase the Result Scale in only one direction, and to do that, we need to dip our toes into the Pro UI.
Open the Water Material Editor and set up the controls as shown in the illustration below. To see the little "f" icon for Displacement, click on the semi-circle and choose "Function" from the menu (the other choices are, as always, "Widget" and "Texture"). We'll do that in a while. For now, set it back to "Texture"

The values for Water and Murk Absorption are RGB values. Higher values for a component mean less of this colour will show in the water, or in the murk. I've set it up to give me clear blue water with green-ish murky stretches and patches. You'll need to experiment with the amounts to see how it all works, and the fact that the RTR doesn't show you the colour of the water doesn't help.
We are controlling the distribution of murky and clear water with a texture. Click on the "t" icon, and follow the procedure as always with textures: call the new Node "Water Murkiness Node" and the Leaf "Murk Texture". Edit the Monofractal. Just change the Largest Feature to 50000 meters. This will result in murky stretches of Sea up to 50 km across. Quite a lot, but it's a Fractal, so there'll be patches in those stretches. Set Gradient Perlin as the Basis Function.
We are using the Curve Editor in the Output Control for the texture to do the Scaling. First, set min/max input to -1/1 to use the full range of the murk calculation. For the output: 0 means clear water and 100 means mud. I didn't really want much dirt, my main interest was the slightly different colour. So, I set the min/max output range to 0/5.
Tweak the Curve and watch the preview until you get a murk distribution you like.

Shaping the waves takes us into the Pro UI. Click on the "t" next to "Displacement" and follow the procedure to set up a new Texture Node and Leaf. Edit the Monofractal, like you have done many times while building this Planet. Set the Largest Feature to 50 meters, and the smallest feature to 0.05 meters, for waves up to 50 meters long and little ripples up to 5 cm. A result scale of 3 makes waves up to 3 meters high. Set the Basis Function to "Voronoi". Clicking on the Triangle next to the list opens the Voronoi Editor with many different options - I find the default looks best. Leave the Output Curve unchanged.
Now, change the Texture to a Function, using the little menu you should have become quite familiar with at this stage. Click on the "f" icon to show the Function Graph Editor. Choose "Auto layout" from the menu on the top, click on the node which represents the Fractal, and you should see something like this, depending on how you re-named things:

The main differences between this and what you already saw in the Main Interface are extra Parameters and 3 values you can change for some of the settings. We'll cover much of this in future additions to the Tutorial. Right now, we are interested in the Largest Feature. The 3 values represent the Largest Feature in the x, y and z World Space directions. We want to stretch the waves. Change the x value, the first one on the list, from 50 to 250 as shown here to elongate the waves along the World Space x-axis. The actual effect on the waves varies, depending on where on the Planet you are. Remember, it's not like the flat "Stage Set" of other programs. The waves happen on the surface of a Sphere in World Space, and if you don't see what you expected, try making changes to the y or z values instead.

Hey, look, we are finished! there'll be additions to this Tutorial as time goes on, and if you wish, I'll put you on a list to notify you of any updates. I can promise you that this is going to be exciting, as I and others, including the people who invented all of this, discover more.