# Modeling a film w/ 50% haze and 91% tranmission.

Hi Tim,

Haze is the percentage of transmitted light which deviates from the
incident direction. So you could interpret the haze to mean that 50% of
the transmitted light is diffused.

As a first approximation I would use trans with the following transmission
properties:
Ts = 0.455
Td = 0.455

Though with a haze of 50% assuming that the scattered light is lambertian
is a bit of a stretch.

Andy

···

On Mon, Mar 11, 2013 at 10:45 AM, Tim Perry <tim.v2.0@gmail.com> wrote:

Hello,

I've been asked to model windows that have a film with 50% haze and
91% transmission.

I do not have a BSDF for the material. The best option I can think of
is to use the trans material with 91% transmission and hope that it
provides about 50% haze. Does anyone have experience modeling film
based on haze? If so, any pointers? A tutorial I should look at?

Thanks,
Tim Perry

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Dear Chris, Andy,

Thank you for the reference and the feedback. I think I'll use Andy's
definition even though the distribution of light is definitely not
lambertian. It should provides sufficiently accurate results for the
task at hand.

I think I'll ask the client if they have a BSDF first though.

Thanks again,
Tim

···

On Mon, Mar 11, 2013 at 11:05 AM, Andrew McNeil <amcneil@lbl.gov> wrote:

Hi Tim,

Haze is the percentage of transmitted light which deviates from the incident
direction. So you could interpret the haze to mean that 50% of the
transmitted light is diffused.

As a first approximation I would use trans with the following transmission
properties:
Ts = 0.455
Td = 0.455

Though with a haze of 50% assuming that the scattered light is lambertian is
a bit of a stretch.

Andy

On Mon, Mar 11, 2013 at 10:45 AM, Tim Perry <tim.v2.0@gmail.com> wrote:

Hello,

I've been asked to model windows that have a film with 50% haze and
91% transmission.

I do not have a BSDF for the material. The best option I can think of
is to use the trans material with 91% transmission and hope that it
provides about 50% haze. Does anyone have experience modeling film
based on haze? If so, any pointers? A tutorial I should look at?

Thanks,
Tim Perry

_______________________________________________
Radiance-general mailing list
Radiance-general@radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general

_______________________________________________
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Radiance-general@radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general