BNA!@Posted: Sun Jan 26, 2003 6:29 pmĀ :
So here we are with a quick and short tutorial how to create that amazing looking textures for Doom3 from 3D models.

Here are all the surce files you need:
Souce file download - 110kb

The download contains:
- a simple 3D modelled panel with approx 11k polys
- a material file for it to spare you writing one of your own
- a grey tga texture I usually use for specular map testing

Now let's go with step 1:
Create a folder structure below the base folder:

Step 2:
Unzip the contents of the file in the panels folder and move the "" to the materials folder in your Doom directory - the rest will sit happy where it is now.

Step 3:
Open Doom, lower the console and type:
renderbumpflat bna/panels/panel_3_trip.lwo

Doom will load the 3D file "panel_3_trip.lwo" into memory and renderbump it with the default settings, which will leave you with two 256 * 256 .tga's.

The normal map will be named:

And the diffuse map will be named:

Now what happened?

The Doom engine took the model, extracted the color information from the polygons and rendered it to a flat color map (which will look even more unimpressive as the underlying 3D model used).

At the same time the engine computed the surface normals in our newly toy - the beloved fancy looking normal map.

When you open up DoomEd and go to the media browser you should find a folder called "bna" and a subfolder called "panels" with one material called "panel_3_flat" in it.
Make a brush, apply the texture, compile the map and see how it's looking.
Well, not overly exciting I know, but you've successfully accomplished the task of rendering a 3D model into a flat texture :)

So far so good.

What are the common pitfalls?

The 3D model has face towards the Z - axis (= looking at you in a front view camera perspective) in your 3D mesh modelling program of choice when you save it.

Make sure you have converted all your polygons into triangles (watch out for these little 1 and 2 vertex polygons)

I had some problems when I did set up a UV map, but don't quote me on that.

What else can you do?

The most important thing is the ability change the resolution of the rendered images.

When you type "renderbumpflat -size 1024 1024 yourmodelfile" you'll get a 1024*1024 resolution image which may be a better source file for building a texture upon it.

For other options just type "renderbumpflat" and Doom will show you the common use of the command with additional options.

Have fun and leave your questions here...