Tutorial: House of Decay

Baking lighting in modo and exporting for Doom 3.

INTRO

I have received numerous requests from co-workers and community designers to make a tutorial explaining how I went about creating House of Decay for Doom 3.I had been messing around with modo a few months back and really got into the rendering aspect of the tool. The soft, realistic lighting was surprisingly easy to pull off. I then discovered that all of this lighting information could be BAKED into a UV map of a model using modo's Render>Bake feature. This REALLY got me thinking.

Hmm...if I built the entire level in modo and then split the level into numerous models with unique UVs, I could achieve unique texturing AND soft lighting on those models and bring it into Doom 3. Sounded reasonable enough and a good little experiment to try.

*NOTE This is NOT a tutorial on how to use modo. This is taking a look at the process I went through in designing the level in modo, splitting the mesh into seperate models and UVs, then baking and exporting for Doom 3. Check at the end of this tutorial for useful resources for modo and other tools.

STEPS

First I will outline all the steps beforehand and briefly explain what is done in each.

STEP 1

The initial idea was to take a favorite Quake 3 Arena level of mine and recreate it in modo with a new, more updated look. I hoped to achieve this new look by baking all the lighting and unique textures into a model-only level and bring it into Doom 3. I chose "House of Decay" (mptourney1) from Quake 3 Arena: Team Arena. I began to run around the level and grab screenshots and also get a feel for the size and space of geometry. Using these screenshots as a guide, I quickly blocked out the spacial geometry in modo. I brought this into Doom 3 and began resizing the model as need be to fit the desired scale. Once I was happy with the blockout, I moved into a first pass detail stage.



STEP 2

This step is where a bit of creativity comes in. I began to detail out the level on a first-pass basis. Example: the wooden roof would be simple polygon shapes as opposed to a more complex shattered, delapidated wood that will be modeled in the next pass. As I designed these pieces, I began to think and jot down how this mesh would best be divided into seperate models for UVs and content management.

STEP 3

Step 3 goes directly into second pass detailing and splitting up the mesh into seperate models. Here I have finished detailing and assigned each seperate model a unique but also logical name that works for UVs and content management.

STEP 4

This was the most difficult step of this entire project. Anyone that has modeled before knows that unwraping a model can be difficult. Modo actually has really, REALLY nice tools for unwraping a mesh which really helped in this step. However, these models are a bit different.

Since we are baking lighting into the UVs on the models, that means EVERY face must be on the UV map. This requires much more time and careful planning since each face will be affected by lighting. This is also good, however, as it results in 100% unique textures for every face of the level. A bit more work, but also very rewarding in the end.

A good idea at the end of this step is to bring the models into the Doom 3 map and throw some temp textures on the models. Now, you can just replace and reloadimages later when you create the actual textures.

STEP 5

Now that the hard part is over, we begin to texture the models. A good resource for high-res textures is CGTextures. I created all the diffuse textures for this project by using sources from that site. Very helpful.

I recommend creating bumpmaps as well. The bumpmaps will really take your models to the next level and the lighting will really help these models "pop". Check CGTextures' tutorial section on a nice normal map creation tutorial. Also check out CrazyBump. Using these techniques in conjunction with each other will really help in creating some clean, accurate bumpmaps.



STEP 6

Most of the work is done. The last few steps are essentially the final passes of the project. This quick step is basically for setting up the actual level in Doom 3 with particles, skybox, sounds, etc. Give your level a bit of life!

STEP 8

Replace the old and busted, with the new baked hotness. Finished product!