| On this page |
Note
In Houdini 13 and later, use of the light linker is discouraged in favor of the light bank.
Overview ¶
The light linker lets you manage links between various nodes.
The light linker lets you link lights to objects to control which lights illuminate which objects (Light Mask), which objects cast shadows from which lights (Shadow Mask), and which objects are reflected in other objects (Reflection Mask).
You can work by choosing which objects are lit by a light (Light-Centric), or by choosing which lights light an object (Object-Centric). For reflections, you can choose Reflector-Centric or Reflection-Centric.
The pane consists of two subpanes the contents of which are determined by the Link type and Mode settings. Each of these subpanes contains a hierarchical display of nodes, groups and bundles . Links are created by first selecting one or more items in the left (source) subpane and then selecting one or more items in the right (target) subpane.
How to ¶
By default, all lights cast light on all objects, and all objects cast shadows from all lights (if they have shadows turned on). However, this is often not what you want, either because it’s inefficient, or because you want to use common but technically non-realistic techniques such as character-specific lights.
You can use light linking to set up specific relationships, so that an object only receives light from certain lights, and/or only casts shadows from certain lights.
You can link lights and shadows interactively using the Light Linker pane, individually for each object and light directly in the parameter editor, or by specifying categories.
| To... | Do this |
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Open the light linker pane |
Click the |
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Illuminate objects |
or On the Render tab of an object, set the Light Mask on the Shading sub-tab in the parameter editor to determine which lights will illuminate your object. |
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Cast shadows from objects |
or On the Shadows tab of a light, choose the Shadow Type from the drop-down menu (The default is No Shadows). Set the Shadow Mask to determine which objects will cast shadows from your light. |
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Reflect objects in other objects |
or On the Render tab of an object, set the Reflection Mask on the Shading tab in the parameter editor to determine which objects will be reflected by your object. |
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Set up the link editor |
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Link source items to target items |
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See the parameter values being controlled by the link |
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new tab icon in the 
Tip
A quick way to add a node to a group or bundle is to drag it onto the corresponding tree node.
Tip
The cells in the spreadsheet column can be edited and multiple cells can be selected by holding Space and either clicking or dragging.
Tip
Channel references are followed when setting mask parameters making it possible to link objects embedded in locked assets.
Toolbar buttons ¶
Select toolbar ¶
Sets the selection to items that match the value in the Select field.
Adds items that match the value in the Select field to the current selection.
Removes items that match the value in the Select field from the current selection.
Pane menu entries ¶
Troubleshooting ¶
I can’t select items in the target list
Possible causes and solutions:
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The read-only button is on.
Make sure the lock button above the right/target list is off (the button is bright yellow when it’s on).
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The parent is a bundle or a group.
You cannot individually link a member of a bundle or a group using the contents of that bundle or group in the tree. This is by design. You will need to find the node in the operator hierarchy in order to link it.
I can’t see my group or bundle
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The group or bundle is not empty, but contains no operators of the expected type. The linker will display empty groups or bundles to allow linking before populating them. However, once a group or bundle is non-empty, the linker attempts to reduce the clutter in the subpanes.
Either add an operator of the expected type to the group or bundle, or create a new one.
