Light-map instrument

Description

Cornell box floor rendered with a light-map 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	List of channels defined by a sensitivity spectrum
user-defined	First output preset
user-defined	Second output preset
user-defined	…

Parameters

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"/>
     </output>
</instrument>