Light-map instrument



Cornell box floor rendered with a light-map instrument

Instrument This instrument collects light reaching a scene geometry.

The scene geometry surfaces are mapped to the result image buffer using the geometry’s UV coordinates. Depending on the uv_window parameter, the UV coordinates may be scaled to fit the image frame, or set to a manual UV range.

Children Nodes

This node may have a variable number of output children with custom names.

Sensor sensor List of channels defined by a sensitivity spectrum
Output user-defined First output preset
Output user-defined Second output preset
Output user-defined


name type description
xresolution integer Horizontal buffer resolution
yresolution integer Vertical buffer resolution
pixelfilter list The ray pixel filter
shutter real Shutter time or exposure, in seconds
wlmin real Low bound of simulation wavelength range
wlmax real High bound of simulation wavelength range
material string The name of the scene material that should collect light
uv_window list The UV scaling mode, may be boundingbox or manual
umin, umax, vmin, vmax real The UV frame coordinates. Defined if uv_window is manual.

Ocean XML 5.0 example

<instrument type="lightmap" name="floorlightmap">
     <prm xresolution="512" yresolution="512"/>
     <prm pixelfilter="bilinear"/>
     <prm shutter="0.8"/>
     <prm wlmin="380E-9"/>
     <prm wlmax="780E-9"/>
     <prm material="floor"/>
     <prm uv_window="boundingbox"/>
     <sensor type="ciexyz" name="sensor"/>
     <output type="rgbimage" name="lightmap">
             <prm colorspace="srgb"/>
             <prm depth="8"/>
             <prm xwhite="0.31271"/>
             <prm ywhite="0.32902"/>
             <prm hcc="0.32"/>
             <prm drawinfo="false"/>