Lights in Grasshopper

Replies to This Discussion

Permalink Reply by Andrew Heumann on November 28, 2014 at 12:07pm

The Human plugin permits some control over lights - you can access the properties of existing light objects, create new lights (linear or point), with control over their properties. However, a technique akin to the one Luis used in this video: http://www.grasshopper3d.com/video/gh-point-light-interaction might be closer to what you want to do, if you want to modify an existing Rhino light and move it around. Here's a script mirroring his approach that lets you dynamically set the position and intensity of an existing light. To activate it, right click the "ID" parameter and choose "Set one Guid" - then select the light you want to modify. 

Attachments:

• SetLight.gh, 5 KB

Permalink Reply by Sean OBrien on December 15, 2014 at 11:57am

Andrew, 

So, I am trying to rotate the surface light.  I am able to get the surface light to move with the geometry that I want it to move with, by creating a relationship between the geometry I am moving and the light using an MD slider.  However, when I rotate the geometry, I am unable to rotate the surface light 360 degrees.  Is there a way to make the light rotate.  It seems like the problem is that the surface light is being read as a guid, which I am not completely familiar with.

Thanks!

Sean

Permalink Reply by SERGEY KUZNETSOV on August 30, 2017 at 2:51pm

Hi!

I need multiple SpotLights.

SetLight.gh works with one points, but it doesnt work with multiple points... How I can to fix it?

Permalink Reply by Sean OBrien on December 15, 2014 at 11:57am

Andrew, 

So, I am trying to rotate the surface light.  I am able to get the surface light to move with the geometry that I want it to move with, by creating a relationship between the geometry I am moving and the light using an MD slider.  However, when I rotate the geometry, I am unable to rotate the surface light 360 degrees.  Is there a way to make the light rotate.  It seems like the problem is that the surface light is being read as a guid, which I am not completely familiar with.

Thanks!

Sean

Permalink Reply by Andrew Heumann on December 15, 2014 at 1:20pm

The light is meant to be read in as a GUID - this is how the script gets access to the light object. 

The script I wrote initially is only interested in setting the location of a light - setting the position and orientation of a rectangular light is a bit more complex. The attached script uses a planar rectangular surface as input to specify the location, orientation, and dimension of an already-existing rectangular light in the scene. 

Attachments:

• SetRectangularLight.gh, 6 KB

Permalink Reply by Sean OBrien on December 20, 2014 at 1:09pm

Andrew,

Thanks for the help!  So, when I create a surface, and then create a surface light, the location of the surface light when i set it does not set precisely to where the surface is located.  For some reason, the light is offset from the location of the surface, which makes it difficult to control the location in relation to an origin point.  Do you know what the problem might be?

Permalink Reply by Andrew Heumann on December 20, 2014 at 1:27pm

it co

Permalink Reply by Andrew Heumann on December 20, 2014 at 2:11pm

somehow that message got cut off funny :)

Sounds strange - but it could have something to do with where the light is defined to begin with. Try creating the light on the world XY plane before you reference its guid. If that doesn't work, can you upload your geometry? I can take a closer look. 

Permalink Reply by tang li qun on March 28, 2017 at 5:35am

In case anyone's still interested in baking rectangular lights, here's one in python, which came from playing around with Andrew's file above.

The python version doesn't take a guid, but then doesn't allow you to control intensity.

It makes lights by taking rectangles as input, toggle true to bake.

I'm only using it to flood a ceiling with rectangular lights, so there wasn't a need to individually adjust light intensities, but I'm posting it here for the people who are looking for something similar (like I was).

Attachments:

• BakeRectangularLight.gh, 4 KB

Permalink Reply by Kyle Ingber on August 3, 2018 at 11:00am

this script is great, thanks!

Permalink Reply by Ya Gao on June 9, 2017 at 8:24am

Hey Andrew,

Thank you for the script. I am fairly new to grasshopper and when I select the light to set one guid for the "ID" parameter, the point light in rhino just disappeared. Do you know what I did wrong here?

Best,Ya