Ladybug cannot do the right analysis on rotated geometries

sunlighthours

#1

Hello all,

I tried to analysis sunlight on building massing. However I find it does not get the right result on some rotated geometries. (some have the blue strips but it should not appear). I also tried on single geometry. I find the blue strips appear after I rotate the geometry. Anyone knows why this happen?

Thank you


#2

Hard to say without the file, but i would check the normal direction of the surfaces.
-A.


#3

I am sorry I am a new user so I cannot upload the attachment file. But I can show you some screenshot. Thank you very much.


Left side is the geometry which is facing north. Right side is the Geometry I rotated. You can find that the right one has some strange blue strips.


#4

And this is the screenshot for GH


#5

Hallo liumo,
I think that building (with the blue string) has a duplicate geometries in the same position and maybe the duplicate geometries has the surfaces in the wrong direction:

You can check with the _seldup Option


#6

Hello gaetano.christian.ruvio,

Thank you for your reply.

But I have tried to remove the duplicate surface, it still has the some problem. And those are all solid so it cannot flip surface


#7

Send a link for the file, until you can upload here.
Also you don’t need to connect the geometry to the context. Unplug it from there.
-A.


#9

Hello Abraham,

This is the definition for GH.

Thank you very muchladybug_2.gh (404.9 KB)


#10

Residential_test.3dm (1.4 MB)

and this is the rhino file for test


#11

Did it work once you removed the geometry from the context_? From my understanding context_ should be used for surfaces you want in your raytracing but don’t want analysed. Surfaces plugged into _geometry will by default also act as context (otherwise everything would be 100% radiated right?).

Also, have you considered rotating the North position rather than the geometry? This will be less heavy in terms of compute for grasshopper (less error prone).

image


#12

Your geometry is too far away from the origin (0,0,0). Theoretically it is not supposed to affect … but it does.
Move it close to origin and you’ll be just fine.
-A.


#13

OK. I got the right result!

Thank you very much!