''Bounce From Surface'' not discarding blocked sun rays


I am a new user to grasshopper and ladybug, and I have ran into a problem when I try to use the Ladybug ‘‘bounce from surface’’ component to do a reflected sun study.

I would like to trace the sun rays that bounce off of the _SourceSrfs geometry and strike surrounding context_ geometry.

At the same time, I do not want to trace any sun rays that are blocked by context_ geometry, nor any sun rays that bounce off of the context_ geometry first and then strike other context_ geometry.

This should be consistent with the stated functioning of the component, but it appears that the component does not discard blocked sun rays.

The context_ geometry info bubble states the component will reflect sun rays AFTER they bounce of the** _sourceSrfs **. The behavior seems not work work like this.

Any insights would be greatly appreciated.



bounce-from-surface-test.gh (377 KB)

Hi Matthew

Glad you joined the community. I’m not quite sure that I understand your problem but from the image I assume that you want to isolate only the bounces from the source surf. If this is the case, I did something similar on a skylight project. See the explation bellow and attached file. Hope it helps.



Find the intersection of the sunrays and source surf (this will return the pas on surf that receives sunrays)

Find the discontinuity of the sun rays (this returns all the sunrays bounces)

-FIRST ISLOATION- Isolate the second (1) and third (2) items from the discontinuity component (last and second to last sunray bounce)

-SECOND ISOLATION- Isolate the second item of the -FIRST ISOLATION- (this returns the last bounce of the sunrays)

Find a target srf that your are interested in evaluating.

Create a Beep with the target geometry (it needs to be a solid geometry)

Find if the pas of the SECOND ISOLATION are inside the target Brep

Dispatch the points of the previous action into true (they are inside) false (they are outside)

bouncefromsurfacetest_CN.gh (386 KB)

Matthew, thanks for the comment and, Claudio, thanks for the response. It sounds like Claudio’s method should work in your case. However, it should not be that difficult to discount sunrays that com