[Maxer]

I was asked by one of the Architects in my office the other day whether or not Maxwell was going to be able to do lighting analysis. I told him that I was pretty sure that it was going to be able to do it and he began to ask me some questions. When we got to talking about glass and how Maxwell treated it as a material he brought up something that I hadn’t thought of and didn't know if it was being taken into account. All glass manufacturers have data on their glass, specifically on the values that make up the glass. It's provide in a chart that tells you the %of visibility transmittance, %of solar transmittance, and % of UV transmittance along with other things, here's an example.



My question is does Maxwell take into account these values, and if it doesn’t how can it correctly account for glass in its calculations?

[tom]

IMHO these can be adapted by measured BSDF data...
but also maybe parametrized within the shader somehow...
again Oscar would give a precise answer to this

[Maxer]

If not I think it should be fairley easy to set up a custom glass shader with these fields so that any type of glass could be used. Anyone from NL want to comment?

[tom]

i agree with you but i'm not sure if it will be physically correct this way ,
you know maxwell will never include physically incorrect ways

[Maxer]

How could it be physically correct without it? If you can’t regulate how much light glass can actually transmit then it's not going to be accurate. Most if not all glass that is used in commercial projects isn't going to let 100% of the light in, and to be accurate there has to be some way to account for this within the material.

[bakbek]

What about multilayerd glass types... such as high reflection value on one side and non on the other... or others. what will be the workflow in such cases - build it actually with the layers, or the shader will acount for that ? ? ? just thinking.

[tom]

How could it be physically correct without it? If you can’t regulate how much light glass can actually transmit then it's not going to be accurate. Most if not all glass that is used in commercial projects isn't going to let 100% of the light in, and to be accurate there has to be some way to account for this within the material.

i was not pointing your subject while talking about "physically correct"...
i just mean the implementation method.... with simple parameters or with measured BSDF....

[oscarMaxwell]

Glass in Maxwell has 2 values that are used in glass manufacture: the abbe number and the nd number ( this is one of the reasons why I implemented these features ). Is prepared to easy handle more manufacture parameters and is my intention to support real glass catalogs inside maxwell.

Best regards.

[Maxer]

Thanks Oscar that is great news

[tom]

I'm confused now...
Oscar, do you mean just the abbe and Nd values are enough?
Yeah, I find them already enough but I'm just wondering if the above
details also needed to be implemented in the future....