Author: Kevin Mahon

Having started into the computer graphics industry as a hobbyist artist in my early teens, I have spent the last ten years or so developing content for simulation titles. Working in the simulation industry encouraged me to develop an eye for realism, which is a passion and primary focus for me as an artist today.

As a recent addition to the Artomatix team, it has been a welcome challenge to develop software that empowers texture artists like myself to create content that is not only high quality but simple and efficient to produce. I thought it would be a good idea to take some time over the coming weeks to take a look at some of my favorite features in ArtEngine and how I use them to create content. 

This week, I will be going through a recent addition to the ArtEngine node library, the Height Blend node. Found in the Composition category, Height Blend is a powerful blending tool that can create complex, detailed materials by blending two materials together based on height or displacement information. I have found this node very useful for creating new materials with both subtle and eye-catching characteristics, Hopefully, this node can do the same for other artists. Today I will be looking at how I created an icy, snow-covered mud material from two separate snow and mud materials, with the ability to output many variations thanks to the power of the Height Blend functionality.

The new Height Blend node is a great tool for adding complex interactions between two separate materials, it is especially useful when applying sediment overlays like snow, sand or dirt to base materials. The node takes a foreground and background material as inputs, with an optional mask to ignore blending on specific areas. 

It has always been extremely time-consuming to merge two materials like those shown above using conventional image editing techniques. Masking out areas by hand in Photoshop to match how two materials interact based on height was always a pain. Using Height Blend now performs this action automatically for all maps in a material, saving me hours of work with a single operation.

The node will blend the foreground onto the background based on the height information from both materials and the four parameters provided in the properties panel. 

Next, I’ll look at how we can use these parameters to change the blending effect on our snow and mud materials to create different effects.

The initial settings above provide me with an interesting light snowfall blend with the mud material, allowing the peaks of the mud tracks to sit above the snow. Though I like this effect, I would like to melt the snow partially to make this material look even more like something I wouldn’t want to walk on.

In order to achieve the thawing snow effect, I lowered the snow Offset slightly so reduce the coverage a bit more and then increased the Falloff parameter. Since this parameter determines the softness of the transition between foreground and background, it gives a translucent appearance to snow that is nearer the base mud layer, simulating my desired thawing effect.

As I further increase the Falloff, the thawing effect becomes more apparent. Now there is mostly ice water in the tyre track crevices. I increased the Contrast slider retain some islands of snow in the center of the thawing patches. Opacity is also being reduced progressively throughout the previous two examples. Since this parameter controls the effect that the foreground height map has on the material, I can aid the thawing effect by sinking the remaining snow into the water below.

Of course, the advantage of using ArtEngine is that with these two individual materials we can create a whole library of variations with a single click. This is the Example-based workflow at its best. This snow-covered mud texture library is great for any winter war zone game scene and only took a few minutes to produce thanks to the power of photogrammetry & Artificial Intelligence.