How to edit the perforation of a material

radiance-general
1

Hallo dear Radiance community,

for a glare study, I was asked at a later time, to consider the influence of a full closed perforated metal venetian blind.
I close in for help on this, because I am not that well versed in creating materials in Radiance.
I need to create this blind and I have this info:

I found this perforated material in my HB library which might help, but how do I replicate my data (perforation diameter and perforation distance) in this Radiance material?

void metal mesh_material
0
0
5 0.16 0.16 0.16 0.9 0.0
void mixfunc y_perforation
6 mesh_material void y_hole perforate.cal -s 0.03
0
1 0.02

I thank those who could help me

2

I found the solution and solved the problem!!

Greetings

3

@Jorn_Eglund I am facing a similar problem.

Could you share your solution?

4

@Jorn_Eglund may have checked out. Also, problem is marked as “solved” even though the solution wasn’t shared, so I’m not sure who is getting notifications.

Can you ask a more specific question, perhaps including a description of what you are trying to model?

Cheers,
-Greg

5

@Jorn_Eglund I realize this is from a couple of years ago, but I think that more than one person would love to know your solution.

Thank you for your time.

6

@Greg_Ward I did not see your reply. I hope you are still available.

I am also hoping @Georg_Mischler might be around to enlighten me on his perforate.cal file and how to manipulate it.

I have designed a facade to go with a building and I want to see the daylighting availability on a single floor. The facade can be described as follows:

  1. 8’ width x 10’ height.
  2. First facade section is basically clear glass.
  3. The second facade (which acts like a hole-y screen) is a metallic, perforated panel with specific size of holes and distances between them.
  4. The third facade is the same as the first.

I am using Climate Studio and was told that for the perforated metal panels, I would need to come up with a new Radiance material.

I put the perforate.cal in the Radiance\bin folder, but I do not understand how to manipulate the contents of the file.

I also created a new material and have tried using variations of it in Climate Studio with no success. Some reference the perforate.cal file in the .rad file and some are meant to be used without the perforate.cal file.

I have read the usman2.pdf and refman.pdf and recently purchased the Rendering with Radiance v1.1 (PDF), as well as other readings on the Internet.

ChatGPT gave me this:

void metal perforated_metal_base
0
0
5 0.6 0.6 0.6 0 0  # Reflectance of 60%, no specularity, no roughness

void plastic hole_material
0
0
5 0.8 0.8 0.8 0 0  # A transparent material for the holes

void mixfunc perforated_metal
2 perforated_metal_base hole_material
4 surf_perforation x y z
0
0
surf_perforation = if((mod(x,10)-5)^2 + (mod(y,10)-5)^2 - 1 < 0, 1, 0);

And I found this on the Ladybug support forum:

void plastic mesh_material
0
0
5 1.0 0.0 0.0 0.0 0.0

void mixfunc y_perforation
6 mesh_material void y_hole perforate.cal -s 0.0024
0
1 0.229167

y_perforation polygon Face_425a49ee
0
0
12 -0.05 -8.5 1.65 0.05 -8.5 1.65 0.05 -8.5 1.75 -0.05 -8.5 1.75

Tl;DR:

I want a perforated metal (polished aluminum) screen/panel, but I am unsure how to manipulate the perforate.cal file and I am unsure if my .rad files are correct.

I could settle for some blinds that allow for 65% of light to pass through when down.

Any suggestions would be greatly appreciated.

7

You really cannot trust ChatGPT on this or any other niche knowledge. It’s more likely to give you garbage than if you were to ask some general question that the average internet can be relied on for. Also, you are replying to a post that has been marked as “solved,” so that doesn’t really help. Here is the original post about perforate.cal from its author, Georg Mischler (a.k.a. “schorsch”):
https://radiance-online.org:447/pipermail/radiance-general/2002-July/000369.html

-Greg

8

The ChatGPT suggestions are mostly wrong.

The other thread you have going on this is more on track. You need to use the -s option as shown in Georg’s linked example to adjust the spacing between hole centers, and the A1 (first real argument) parameter to adjust the hole size relative to spacing. I hope this helps.

-Greg

1 Like
9

Sorry about all of my nonsense…I got desperate.

I wish there was a forum for ClimateStudio, as it is what I am trying to please. I thought of doing an Old Testament sacrifice, but I am not really into that.

Thank you nonetheless for responding and yes, it does help.

10

We could start a sub-forum for ClimateStudio. We have one for OpenStudio, which is only somewhat supported, and DAYSIM, which is pretty outdated at this point…

The main issue with ChatGPT is that it’s hard enough answering people’s questions without being confronted by a tidal wave of errors with no discernable origin, if that makes sense.

It helps to be very specific with your question . Offer all your relevant inputs, the unexpected result you got, stating exactly what you did expect if it’s not obvious.

There is a lot to wonder about in Radiance, it’s true. I think that’s why we’ve never pulled together a decent FAQ. Most questions are unique, and the number of repeats is low.

Cheers,
-Greg

1 Like