Mappings File Format

The "mappings file" is the central point of control for RenderToolbox3. It connects the Collada scene file, the [conditions file](Conditions File Format), and the renderer [adjustments file](Adjustments Files). It allows these files to exchange values, and allows the user to introduce new values.

The mappings file contains multiple [mappings](Mappings Syntax).

Layout

The mappings file should be a plain text file with mappings laid out in blocks. A mapping is a single line of text that modifies part of the scene. A block incorporates one or more related mappings.

A simple mappings file might look like this:

Collada {
    % swap camera handedness from Blender's Collada output
    Camera:scale = -1 1 1
}

Generic {
    % choose the dragon's material and color
    DragonMaterial-material:material:matte
    DragonMaterial-material:diffuseReflectance.spectrum = (dragonColor)
}

This file has two blocks, each begins with a name and is enclosed in {} braces. The first block is named Collada and contains one mapping. The second block is named Generic and contains two mappings. Block names determine how RenderToolbox3 interprets each mapping.

Comments

Any line that begins with a % character is ignored as a comment. For example:

Collada {
    % on second thought, don't swap camera handedness
    %Camera:scale = -1 1 1
}

Conditions File Variables

Mappings may contain named variables enclosed in () parentheses. These variables should match variables in the conditions file. For each condition, parenthetical text will be replaced with matching variable values.

For example, consider a mapping with parenthetical text for the variable dragonColor:

DragonMaterial-material:diffuseReflectance.spectrum = (dragonColor)

Also consider a conditions file that specifies the same dragonColor variable:

dragonColor
red.spd
gold.spd
orange.spd

The conditions file specifies 3 values for dragonColor, so the scene would be rendered 3 times. Each time, a different value would be substituted into the mapping, in place of the parenthetical text (dragonColor).

See Conditions File Format for more about conditions files.

Blocks

Blocks incorporate related mappings. Blocks have names, which help RenderToolbox3 to interpret mappings correctly. Blocks can also have groups, which allow users to activate and deactivate specific blocks.

Block Names

Block names determine how RenderToolbox3 interprets mappings and applies them to the scene. There are 4 valid block names:

• Collada mappings modify the Collada scene file.
• PBRT mappings modify the the PBRT scene adjustments file.
• Mitsuba mappings modify the the Mitsuba scene adjustments file.
• Generic mappings modify the scene adjustments file for either renderer. A few Generic Scene Elements are defined in RenderToolbox3.

Blocks with any other names will go unused.

PBRT, Mitsuba, and Generic blocks can introduce scene elements that Collada doesn't know about, but renderers do know about. This includes sampled spectra. Mappings in these blocks apply to on the [adjustments file](Adjustments Files) for the current renderer.

Block Groups

Blocks can belong to named groups. Groups allow some blocks to be activated, and other blocks to be ignored. The group name must follow the block name:

PBRT plasticGroup {
    % specify PBRT-style plastic material stuff
}
Mitsuba plasticGroup {
    % specify Mitsuba-style plastic material stuff
}
PBRT metalGroup {
    % specify PBRT-style metal material stuff
}
Mitsuba metalGroup {
    % specify Mitsuba-style material stuff
}

Here there are 2 pairs of blocks: one pair uses the group name plasticGroup and the other uses the name metalGroup.

The 4 blocks could be switched on and off in pairs, with a conditions file that specifies a groupName variable:

groupName
plasticGroup
metalGroup

Blocks with no group name are always used. If the conditions file does not specify a groupName variable, all blocks are used.