Color Face Attributes, reflections and light transmittance

[TK]

Hi,

Is there a way to visualize face reflections and transmittance values?

I have tried the Color Face Attributes. Is there a way do deconstruct and find these values using existing Modifiers?

Thanks!

[mikkel]

Hi @TK,

I understand you do not want the modifiers as seen below, but the actual values? If so you can input properties.radiance.modifier.average_reflectance instead of properties.radiance.modifier.display_name, then you will see the reflectance. This will not work for glass modifiers of course. The Glass modifier class has an average_transmissivity property that you can input as well, but no average_transmittance property. Is there any way to visualize the transmittance values with ColorFaceAttributes, @chris?

[TK]

Cool, thanks Mikkel.

Is it possible to make this standard in the dropdown list? Displaying transmittance would also be very useful for visualizing and checking models.

By the way, where can i find all the properties input commands?

[chris]

That’s the correct way to do it @mikkel !

There is, indeed, a way to get transmittance from transmissivity and I think the only reason why @mostapha hadn’t implemented it on the honeybee-radiance glass modifier was because it requires a little clever root finding. But I put some root finding methods into ladybug, which are up to the task. So I just exposed transmittance properties for the Radiance glass modifier:

fix(glass): Add properties for transmittance

Also, adding the average_tranmittance and average_reflectance to the dropdown seems reasonable enough and I just pushed an update to the dropdown component for them:

But, across all of the modifiers supported by Radiance, there are hundreds of possible properties and I’m definitely not going to add all of them to the dropdown. For all other properties, simply connecting a string with the property name to the “HB Color Face Attributes” component is the way to do it. If you want to see all of the properties of all the modifiers, you should look through the docs of the modifiers submodule in the honeybee-radiance docs:

https://www.ladybug.tools/honeybee-radiance/docs/honeybee_radiance.modifier.material.html

The materials that have been fleshed out the most are:

• plastic
• glass
• trans
• metal
• mirror
• bsdf
• glow

[TK]

Outstanding, thank you so much!

[mlk]

@mikkel

properties.radiance.modifier.average_reflectance

Hi @mikkel ,
The solution was interesting to me.
Would you guide me find the answer of my problem?
I have obtained UDI of a room using LBT. I didn’t define any construction and it uses the defults. how can I find solar reflectance and visible reflectance of faces ?

[Wu]

Hi, Chris.
I have a question for you. My research content is the indoor light environment of different materials glass, DA, UDI, etc. So, in the input “_trans” of the “HB Glass Modifier” component in HB-radiance, is it necessary to input the transmittance of the glass material or the visible light transmittance? You know there is a clear difference between the two physical quantities.

Mr. Wu

[chris]

@Wu

is it necessary to input the transmittance of the glass material or the visible light transmittance? You know there is a clear difference between the two physical quantities.

I’m not sure what you are talking about here, @Wu . Are you talking about the difference between solar transmittance vs. visible transmittance? Or are you talking about the difference between transmittance vs. transmissivity?