In my previous blog (“Making of Veridia: Creating concept art, from text to 2-D”) I discussed how I used our Graphic Bible to come up with concepts for the objects and environments that will be in our first episode, Veridia. For this installment I will go over the methods I used to take my concept drawings and create final 3D artwork that the player will be able to see, and often times play around with, in the game. The beauty of concept art is that it gives you a jumping off point when creating a 3D model. Think of it as a roadmap, so to speak. The great thing is that the concept art is not necessarily the end-all be-all. It’s a place to begin negotiations. After presenting the concept work to the rest of the team, small changes can and will most likely happen (hopefully for the better).
The hatch above and the mushrooms below are actual examples of concept art and completed assets for a couple objects that appear in Veridia. As you can see there are subtle changes from the source concept and the completed models. The reasons for not following the concept artwork to a T varies from instance to instance. However, the end goal is to always have a model that looks nearly identical to the 2D concept artwork while keeping the game requirements in mind.
Another crucial point I have to keep in mind: video game models are made up of little squares called polygons. If a model is too detailed (too many polygons) it can slow down a game. If you ever played a game and it suddenly gets all jittery (sometimes called ‘lagging’ or ‘chugging’), this is because there are too many polygons on the screen at once. So while I’m modeling I have to make sure I have as much detail as I can without going over the limit for that individual object. Not an easy task.
The next step is a bit more fun. Once a model is completed I have to add a texture to it. Without texturing a model is just gray and boring (see left). Before I can add a texture to a model, I have to unwrap it. Unwrapping is when an artist takes his model and maps out it’s polygons on a grid. The end result looks similar to as if the model was flattened. This is called a UV Map.
Mushroom UV Map
Now that the model is flattened I can paint my texture. Usually I import the unwrapped model’s UV map into a painting program of my choice (Corel Painter, Adobe Photoshop, etc.). I then paint on top of my map using a special piece of hardware called a tablet. The tablet lets me use a stylus like a paint brush to create unique textures that have a stylized feel to them. I use a combination of texture samples extracted from photographs I have taken and hand-painted colors to create the specific effect I am after.
Without Ambient Occlusion
The final step is to have my 3D program create a special file called an Ambient Occlusion Map. Ambient Occlusion simulates the way light reacts in real life, specifically the soft shadows created when objects get close to each other. I use this Ambient Occlusion Map to add darkened areas to my texture file. These dark areas represent where shadows are being cast.
With Ambient Occlusion
Now that the model has a texture I am ready to add the finishing touches. Modern day computer graphics utilize a special file called a normal map. Normal maps allow a model to look more detailed than it really is. For what purpose? Doing this is a way that the model can appear to be made out of more polygons than it really is, thus giving more detail and better sense of reality to the player’s eye. These lone maps are why modern games look so good. The other file I use is called a specular map, it controls where the object is shiny and reflective, as well as the intensity of the shininess.
Mushroom normal map
There are several ways I can make normal maps, however most recently I have been using a program called Crazy Bump which streamlines the creation of normal maps. I simply use my texture file as the source and Crazy Bump will spit out a normal map. This method does come with its limitations. Crazy Bump is limited to the detail present in the texture file and requires a lot of tweaking for the normal map to be at its best. Crazy Bump can also make specular maps. They’re made in much the same way as the normal maps. Once I am happy with Crazy Bumps’ normal and specular maps I export them.
I am now ready to apply all three files (texture, normal, and specular) to the model. It’s a long road from concept to completion but its worth it to have top notch game assets. You’ll see for yourself when Veridia hits the Android Market in a couple months. In the meantime, we’ll be showing off more graphics in our future “Making of Veridia” blog posts!
