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NAME

td - set the diffuse transmittance for the current material

SYNOPSIS

td tau_d

DESCRIPTION

Set the diffuse transmittance for the current material to tau_d using the current color to determine the spectral characteristics. This is the fraction of visible light that is transmitted through a surface equally in all (transmitted) directions. Like reflectance, transmittance is measured according to the standard v(lambda) curve, and assumes an equal-energy white light source. It is probably not possible to create a material with a diffuse transmittance above 50%, since well-diffused light will be reflected as well.

The default diffuse transmittance is zero.

EXAMPLE

# Model a perfect spherical diffuser, i.e. light hitting \
	either side will be scattered equally in all directions
m wonderland_diffuser =
	c
	td .5
	rd .5

SEE ALSO

c, ed, ir, m, rd, rs, sides, ts