I am trying to run a View Analysis, but I am getting no results, am I missing something? The visualization seems to not be getting anything.
quality_views.gh (190.8 KB)
The floor (the surface you want to check) is completely enclosed by the brep, so the results will be 100 (in your case, see below) or 0 for all grid points.
100 happens in your case because the normal direction of the floor points outside of the space, so it is completely unobstructed.
0 if you flip the normal direction (as it should be), but because of what i said at first, the grid points are blocked by the space boundaries.
-A.
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@AbrahamYezioro thank you so much for your reply!
So what I am trying to achieve, is LEED V4.1 Quality Views credit that establishes “Provide occupants in the building with a view to the outdoor natural or urban environment for 75% of all regularly occupied floor area.” and that is it.
So wouldn’t I need to enclose the surface I want to check (which is the floor area) with all the walls that would be blocking the view to the outside? I left a window area unmarked, but it does not even take that into consideration?
I recommend to check the example in hydra that shows how to evaluate an internal space regarding he view to the outside (not for LEED).
It is a Legacy example but the principle is there and i’m sure you’ll manage.
Please report your advances on this.
-A.
The hydra example doesn’t work as expected in Rhino 7. But if you just use the ViewPercent of LBT it is pretty much straight forward to make it work.
-A.
@AbrahamYezioro I did use the ViewPercent of LBT, if you want to check, the file is attached in my explanation post like the first on of this topic. Am I missing something in that script that is stopping it from working the way is supposed to?
You need to have the window hole in the facade (no window geometry).
I would also rise a bit the test surface to head height.
-A.
Hi.
Were you able to find a solution to this? it doesnt seem to be working for me either. I even tried the sample file from hydra and even that is showing me 0% views.
Edit: Nevermind. It doesnt work on Rhino 7. Have to use Rhino 6 for it.
Yes, I just had to elevate the test surface to 6’ and it worked ok. Now I’m having other types of issues with it, such as the new version not automatically transforming meshes to surfaces.
Yes, what you said. It doesn’t work on Rhino 7. You must update the components to newer Ladybug (vs Legacy) components.
One issue I’m having that I haven’t seen come up yet: views from inside one part of the building to the sky are being blocked by other parts of the building. A person could see out the window, but what they see is another wing of the building, not the sky. Or another tower across a courtyard - same issue. For LEED v3, this should still count as a “view”. I haven’t figured out an easy workaround yet.
I’m able to get the hydra example to provide great results in Rhino 6. That’s only for the View Factor calc but it’s really useful. It’s able to easily evaluate rooms with more than one window. I made a couple changes to help me understand some of the inputs and outputs. I’m too new of a user to attach the GH file, sorry.
One burning question. Did Mr. Pizzaro perhaps make a math error in his study referenced in the hydra page? In it he stated 20° of horizontal view angle is about 2% of 360°, which is the threshold one sets in the GH component for pass/fail View Factor. Wouldn’t that really be be 5.6% (20°/360°)? Just trying to confirm thresholds as I’m scaling this up. This is a fantastic example file and I’m very grateful for it. Thanks for help!
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OK I answered my own question. It looks like the vectors LB makes define the view quantity in square degrees more or less. A 20°x20° patch requires 21 vectors x 21 vectors seen by exterior to make sure you’ve got the full angle, amounting to 441 vectors. The total possible number of vectors here is 60° vertically x 360° horizontally, so 61 vectors vertically by 360 vectors horizontally (there isn’t an extra vector horizontally since it’s continuous. That amounts to 21,960 vectors. 441 ÷ 21,960 = 2.0% just as Pizzaro stated.
View Factor defined in the Heschong Mahone Group study is based on the least of the horizontal or vertical view angle, however. For View Factor level 4, 20° is the minimum view angle. A 20°x20° patch is the very least number of vectors required to achieve VF4. A worse condition would be a 20° horizontal x 60° vertical patch that would still only be VF4, since it’s the least open view angle that governs. That latter condition is 1,281 vectors, or 5.8% of all possible vectors, still only VF4. Worse yet is a situation where you’ve got your minimum 441 vectors but it’s 60° high x 7° wide, since it’s the 7° part that determines view factor. This case would only get you a View Factor of 2. 
This is a great workflow and the value of the output is fantastic. It’s just to say that unless there’s a way to specify a minimum number of horizontal or vertical vectors on the way to totaling up vectors, it will still need someone to check it before, say, submitting a plan for LEED credit verbatim.
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