Light rigs are all the rage these days. They help get things going. Although we all know that one light rig never fits all. That doesn’t mean they are not useful. Here is a quick way to export your meticulously laid out Houdini light rig setups and import them into other scenes, share on social media and print out flyers for social gatherings.
The Data Tree
I first want to draw your attention to the
Data Tree pane. If you are not familiar with it, you should really make the time to get acquainted with it. You can do all sorts of useful things to manage your scenes through a single interface. It gives you a spreadsheet-like editor that gives you the ability to edit parameters and attribute values on nodes and geometry in a Houdini scene. Basically, it allows you to tweak objects in bulk. If you want to draw parallels, maybe the Structure Manager in Cinema 4D? It’s like a central command center. Kind of.
Data Tree pane is composed of three views which are accessible through the drop down menu on the left-hand side. The
Object Appearance view allows you edit the display of your objects or change materials. Then there is the
Material Stylesheet view which lets you work with style sheets to alter the appearance of your objects at render time. You can do a lot of fancy stuff here. If you’re interested in learning more about Material Stylesheets, Side Effects has a Masterclass that covers them in detail.
Finally, the section were are interested in is the
Light Bank view. This view allows you to edit the values on all lights in the scene, including linking lights to objects, changing intensity or color, changing the shape, and soloing the lights. Soloing the lights is a nice way to quickly tweak your lighting and see how each individual light affects the scene.
Export & Import Light Rigs
Here is the cool bit. Once you have a lighting setup done, you may want to keep it around for future use or just to share with your colleges or the folks at the local pub. Sure you can give them the scene or go through the trouble of deleting everything except the lights and saving that out but here is an alternate way.
Light Bank view, if you click the
Export Light... button, Houdini will save out a file with all the information pertaining to the lights in the scene. This includes light intensity, color, position, etc. The other great thing about the file Houdini saves out is that it’s in
JSON format which means you can programmatically manipulate the file through Python, Ruby, etc. This can be handy for elaborate pipelines. A quick note is that Houdini will want to save out the file with an
Importing the light rig into a scene is as easy as clicking the
Imports Lights... button. Search for your
.lrig file and BAM!