Mapping Shield Lands Part 6: Coloring to the Land


Back to the techie side of mapping again for a first look at texturing, the art, and craft of coloring computer generated objects, in this case terrain. As always when it comes to CG terrain creation nothing is straight forward, so texturing will be done in stages. Texturing is in many ways the best part of my work; you get to see that the awkward looking mess you have been working on for a long time suddenly start coming to life. It is extremely rewarding, and I often get lost in details and dream of who and what lives there and the events taking place. Making sure that stories set in the area I am working on have a suitable location, is a part of my checklist all the way from early terrain generation phase to the end of texturing.

The primary purpose of texturing is to make the terrain look realistic, inspiring and give detailed information of what a certain area consists of, rock, sand, march grass or forested for example. For a map that is going to be used in a single way in a specific medium like printed on a poster, then you create a texture with the right resolution sharp enough to retain all the details in the final print. Printing needs can vary from small cards to wallpaper for a living room wall, all with different needs for resolution and detail.

RPG needs in the future will span a much wider need than prints, VTT’s, PDF’s, Geographical Information Systems and Game Engines are the ones I am aware of now, but more will come I am sure.  When you do a project of this magnitude a key part is to make the most to assure usability as possible and make the results customizable, prolonging their life. For example, forests can grow in places and be cut down in others, seasons come and go, and demons might invade, or magic calamities affect the lands.  In all these cases it is good to know what the terrain is made of and what grows there. That way you can turn all the vegetation in an area brown, black, or grey to indicate a blight, or change the color of deciduous trees to indicate fall but leave the pines and other evergreen trees the same color for your seasonal maps. This can speed up editing and improve the result a lot but providing the right data in the right format.

Area data is mostly stored using masks, a greyscale image with brighter pixels indicating a presence of something. This is great when you want precision, like for elevation using heightmaps. Another way of storing areal data is to use a Splat Map, it is a color image using each of its RGB channels to store data of some variable. Some image formats like PNG also comes with a transparency channel with means you can store four masks in the same file, improving storage efficiency and handling. For other use cases you do not need precision, instead you need to know which of several variables a particular area has, so you can use the color of that pixel to indicate a binary value. This way you can replace lots of masks with one image and save lots of storage and by using the appropriate colors also make them directly usable. Below is the set of colors I have used for my Shield Lands Splat maps.

By using various selection tools in World Machine, you can decide what type of terrain goes where. Remember I wrote about lakes and rivers in an earlier post, the result of that work was a mask that is now the source for which pixels will be water. Selection can be straight forward, like above or below a certain elevation, to extraordinarily complex like erosion flow zones phasing between 90 to 270 degrees and with and not steeper than 55 degrees for example. The variations are practically endless, but the key is to try and figure out where trees or grass grow turn that into rules and select for it. Below is an example of what a splat map in progress can look like.

And with added shading to make it more understandable.

It is still very much a work in progress, trees and bushes are still to be added and just like with the rivers an artistic step using Photoshop is needed to polish it up and remove some ugly bits that pop up here and there. To assist in the Photoshop editing the same masks that was used in the water editing can be used in this step as well. Since we are not messing with the elevation the terrain stays consistent and we can eliminate changes to the terrain that so often comes from changing the size and placement of the render area, which means you can create a smaller render area to quickly preview it in full resolution. When you work with elevation fractals the previews can be very misleading, by getting all the terrain building done in the first phase we now have a much more stable and predictable environment to work in getting the details right.

Splat Maps also have a key function as a coordinator between formats, for example to make sure that the large format texture matches the details generated in a game engine gets textures and models of trees and bushes in the right place and of the right type. Another example is in GIS you can use the Splat Map to create matching vector shapes and styles that are in the right place.

By using colors that are reasonably natural even the plat map can be understood and useful, but it is as a template for creating the final textures it shines. Looking at it even in this unfinished state I like it and combine it with the elevation, and we can start to see the final landscape emerge.

Next installment in this series will be creating the final textures using World Machine, Photoshop, and the Splat Map.

Thank you again for all your support!!