An Advanced SOPack Tutorial

This tutorial explains the steps I used to create the Canyon de Chelly image.  It is not comprehensive, but builds on information found in the Overlays Essentials tutorial and the Strata Essentials tutorial. 

There's nothing too new here, but it shows how to put all the essentials together and make a real image.

Step 1:  Creating the Masks

The biggest challenge in creating a realistic surface map using SOPack is to create good masks.  In this image, I started with a DEM of Canyon de Chelly.  I imported this into World Machine to create masks using the erosion and thermal erosion effects.  The rest of the masks I drew by hand using Photoshop.

The terrain is a combination of 4 DEM files of the real Canyon de Chelly.

The files were assembled and exported to a .ter file using 3DEM.
(the use of 3DEM is beyond the scope of this tutorial)

I used World Machine to import the terrain and create masks using standard (water) erosion and thermal weathering.

This was done using v0.98.  v0.99 has even more erosion mask options.  Visit World Machine's website for more details.

Also check out this tutorial for more info on creating and using World Machine masks.

The first mask I created was the Flow Map  It was created from the Flow Map output from the Erosion device. 

The white parts represent the places in the terrain where water erosion is strongest.

After creating a mask, I increased the contrast of the bitmap image using Photoshop.  This increased the amount of white and reduced the amount of gray, effectively increasing the coverage and eliminating any colors from underneath showing through.

I used this mask for the canyon floors.

The second mask I created was the Talus Age mask.  It was created from the Talus Age output from the Thermal Weathering device.

A talus is a pile of sloped dirt and rock that has collected at the bottom of a cliff due to erosion.

No increase in contrast was necessary for this mask.

When applied over top of the flow map mask, it does two things:
It defines the border between the canyon floor and the talus.
It allows me to apply textures to the talus slope.

The last mask created with World Machine was the Talus Depth.

I increased the contrast on this mask also to accentuate the layer and to remove the gray areas from the cliff face (which would have allowed Talus to show through from underneath.

This is applied on top of Talus Age and masks the cliffs perfectly.
This allows me to apply strata and an overlay just to the cliffs.

I created this mask by drawing over top of the Talus Age mask using Photoshop.
This defines where the trees around the river bed will appear.

There is one mask not pictured here - the river itself.  The river mask is actually 1 pixel wide at 2048x2048 resolution even though the terrain itself is only 1024x1024.  I used this large scale because smaller resolutions were making the river too wide.

The important thing to realize is that textures and masks can be any size - the larger the mask or texture, the more detailed the result of that mask or texture will be.

Step 2:  Putting it Together

Here is a copy of the surface map hierarchy I used in this image. 

Keep in mind that surface layers lower on the list are applied on top of surface layers higher on the list.
For instance, the Cliffs layer is on top of the Talus layer.
Also keep in mind that sub-layers are applied only within the confines of the parent layer.
For instance, Sage will only be seen within the Talus layer, but will be applied on top of Trees.

Once the masks were created, I applied them to the surface layers using the "Tex" button under Advanced Distribution.
I selected Surface Distribution Version, and used type "Transparent".
Lastly, I made sure the Coverage and Fractal Noise sliders were all the way to the left so that there is no native Terragen coverage and no fractal noise.

The layers were matched with their matching masks:

Canyon Floor - Flow Map
River Bed Trees - hand drawn Trees mask
Water - hand drawn Water mask
Talus - Talus Age
Cliffs - Talus Depth

No masks were needed for the sub-layers, they are just splotches of color really.  I just used a basic layer with high Fractal Noise.

Once the masks were in place, I gave each layer a different color and rendered the image to make sure the layers were all in the right place.  I find this step useful because mistakes are easy to see.

Once I verified the surface layers were showing in the correct places, I applied strata and seamless textures to each of the layers, starting at the bottom of the list.  I used Strata with values -10 to 50 for the height and used a Strata Height Map with Height variance of 10.
I used the top "Tex" button under Base Surface and selected RGB version for the rest.  I used type: "Addition" for the Cliff Overlay and type "Total Overlay" for the rest.

Incidentally, the Strata Height Map was created using a screen capture from the terrain creation window of Bryce. (I Knew someday I'd find a use for that old copy of Bryce 4 I have laying around).  Strata Height Maps can be created in a variety of ways, from using real terrain height maps to using grayscale clouds.  Be creative, all you really need is a grayscale image with gradual random shifts from white to black.

The other textures (for the most part) are free seamless textures I found on the web.  A couple (such as the water texture) I created myself.

Cliffs:
Strata was darkened from original and contrast lowered.
Strata Height Map was applied with 10 unit height difference between black and white.
Cliff Overlay was darkened and applied as type "Addition" with tiling of 60

Strata sample	Strata Height Map	Cliff Overlay texture

Other Textures:
Talus Ground was the base texture for the Talus layer.
Trees were applied on top of Talus Ground and also on top of Canyon Floor.
Sage was also applied on top of Talus Ground.
Water was applied to river layer.
River Trees were applied to River Bed Trees layer.
Soil was applied to Canyon Floor.
All were applied as total overlay with tiling between 75 and 200.

Talus Ground	Trees	Sage	Water	River Trees	Soil

One issue I had was that the water texture kept appearing bumpy, in spite of how I set the bumpiness and mimic terrain sliders.  I finally resolved this by setting the Scale Depth slider all the way to the right, increasing the size of the bumps until ultimately, it appeared flat. (counterintuitive, but it works).

Once everything was done, I added a basic atmosphere, and rendered.

Lastly, I made sure I had all the settings written down so I wouldn't lose them.  Again, this will not need to be done with the next version of SOPack.

email me with any questions or comments.