Using BMRT 2.4 with MAYA.

1. The first step is to download the latest and correct version of BMRT. BMRT runs on almost every platform.

2. Install BMRT to a drive with sufficient space. Preferably a render drive.

3. If you are using a Windows version you will have to set two enviornment variables. One leading to the BIN directory and one leading to the SHADERS directory.

4. Start Maya and go Window>General Editors>Plug-in Manager. Make sure that the RIB plug-in is loaded.

4. Create a simple scene with a sphere, ground plane, and a spotlight. Turn on deph-map or ray traced shadows and set the light intensity to 30. The default settings for lights in Maya are too low to see in BMRT. Bumping up the light intensity 30-40% will alow you to see them in BMRT.

5. Go File>Export all. Open up the options and pick export type RIB. Save it to the EXAMPLES directory of BMRT.

6. Start up a DOS prompt and navigate to the EXAMPLES directory where you saved the RIB.

7. Render your RIB by typing: rendrib -d -radio 50 myfile.rib

The switch -d tells BMRT to render to screen. The switch -radio tells BMRT to render radiosity and 50 is the number of radiosity samples.

You should get an image similar to the one below. If you look close enough you'll notice that the image lacks shadows.

8. To fix the shadow problem we'll have to edit the RIB file. Open the RIB file in the text editor of your choice. In this example I'll use Windows Notepad. Go Edit>Search: lightsource. Add the highlighted line of code before the LightSource line. This will allow you to turn shadows on or off.

9. Save the RIB file and re-render: rendrib -d -radio 50 myfile.rib

Your image should now contain shadows.

10. BMRT comes with some uncompiled example shaders. Uncompiled shader files are written in C++ and saved with the .sl extension. You will have to compile the .sl shaders to use them in your render. Compiled shaders have a .slc extension. Only compiled shaders will render in BMRT or Renderman. To compile the glass shader you would type:


Typing this produces a glass.slc file which is a compiled shader. Information for Programming shaders for BMRT or Renderman can be found here.

11. Lets add the glass shader to the sphere in our RIB file. Open the file back up in Notepad if you closed it and find the line of code with the sphere information. By default all of the objects in Maya have been given a "matte" shader. Replace the "matte" shader with the "glass" shader.

12. Save and re-render.