So now we have all of the texture maps that we need to make a good looking map for the rock face we are going to be working on, we now need to think about how each of the materials is going to be distributed. Obviously, all of the maps cannot be shown in full at the same time, so they must be made only visible in certain sections. While this is entirely possible to do in the function editor of your program, for example Lightwave, or even Vue, I prefer to use Photoshop, for a number of reasons. Firstly the control in Photoshop is much easier in my opinion, and you also have the option of drawing directly onto the model, which is fantastic.
To start off this section I am going to open the model in Photoshop. To do this, you will need and Extended version of Photoshop, newer than CS3. I am going to be using the format .obj as I find this usually works best for me. If you are using Lightwave, you can download a plugin for Photoshop from your “downloads” section of your Newtek account.
Before exporting your model, you should create a dummy uv map with the same dimensions that you plan to use, apply it to the model via uv mapping so that photoshop draws onto the same uv map that you expect to use later in the texturing.
In Photoshop -> File -> Open -> model.obj
You will be presented with the following..
double click on the layer with the 3D model in it to open up the toolbox for 3D models. This will give you tools similar to those that you will find in the 3D package you are using to create models, e.g. rotate, pan etc.
The reason for opening the model in Photoshop was to draw on areas that we might expect to see moss. For the purposes of this model, I want this to be around the area that there is a distinct change in the direction of the polys, so where we would expect the rock outcropping to change direction. I will also be creating a second map, where I will place lichen, this will be on the surfaces that face upwards. To do this, take the brush tool, I have it set at 45px with a blurred outline, and simply draw on the model where you want the moss to be.
Open up the texture map that is applied to the model in Photoshop so you can follow your progress. Below are the first versions of the placements that were created.
The decal for the moss placement.
The decal for the lichen placement.
It is now time to set up the main file that will be used for texturing the model. As a base material I am going to use the texture map that was created in the first part of the guide called “rock1”. To do this I will close down all the open windows in Photoshop, and then open the file “rock1.bmp”. Save the file as rockface-tex.psd” so that we keep all of the orginal texture maps in case we need to make some adjustments and or a variation on the texture of the model that will be used in the end.
Open up the moss texture map in Photoshop, and copy it into a new layer in the “rockface-tex.psd” window. We will use the decal that we just created to determine where hte moss will be placed on the texture map. So I will open the decal and copy it, then in the moss layer of the “rockface-tex.psd” click “Add layer mask” then press alt and left mouse click on the new white window that appears. This will allow you to edit the layer mask directly, so copy in the moss decal. Having made the schoolboy error of getting the alpha colours the wrong way round, I have to invert the colours from black to white, by pressing control and “I”. this gives us the following result.
Im not entirely happy with the distribution still, its a little too starchy for my liking, and I find that the moss is a little too overpowering. To remedy this, I will reduce the opacity of the layer slightly, and make the edges of the moss slightly rougher. It now looks as follows:
I’m going to do basically the same thing with the lichen map too, except that first I will get rid of everything in the texture map that is not lichen.
It is important to check how the model is progressing throughout the development of the texturing process so lets see how it looks.
Not bad, but still needs a lot of work. There’s plenty of parts where the textures just aren’t coming through very well. In the next part, there will be more focus on the introduction of smaller details to give a greater depth to the model.