# Modelling 'LitraCon' Light-transmitting Concrete

Hi Terry,

This is no help, really, but I would suggest transdata with some appropriate angular measurements. Are there any? Plain transmittance isn't enough to capture the distribution of light, which I wouldn't expect to be diffuse. In the absence of any measurements, I suppose you have to assume it's close to diffuse and use their value of 3% of 88% for 4% fiber volume density. So, that works out to a formula of:

transmittance = 0.66 * fiber_density

You can then plug this into a trans primitive:

conc_pattern trans litracon_TM
0
7 {refl+trans} {refl+trans} {refl+trans} 0 0 {trans} 0

(Replacing the things in curly braces with appropriate values.) I don't know what the reflectance is -- between 10% and 30% I suppose but they don't say. As for the concrete pattern, you can use a noise function if you like, but I doubt it would look very convincing up close:

void brightfunc conc_pattern
2 '1+0.2*fnoise3({sca}*Px,{sca}*Py,{sca}*Pz)' .
0

You'll have to pick the scale to suit your coordinates, and you may want to use different ones for Px, Py, and Pz to get a grain appearance, for example.

-Greg

P.S. I love the spotlight selector thing on their website -- very hip.

···

From: "Terrance McMinn" <[email protected]>
Date: October 18, 2006 7:57:40 PM PDT

I have a student who is currently designing a museum for his
dissertation. Can anyone offer advice in modelling this
Light-transmitting Concrete
(http://www.litracon.hu/building-blocks.php)?

For those who have never heard of this material before, it is basically
concrete with embedded optical fibres.
Initial thoughts are to model as 'trans' material modified with a dirty
function for the opaque areas, though there is a definite suggestion
that the optic fibres be arranged in rows or columns within the block.

Regards

Terry Mc Minn
Faculty of Built Environment, Art and Design
Curtin University of Technology
GPO Box U 1987 Perth 6845 Western Australia
Email: [email protected]
CRICOS Provider Code: 00301J