Houdini 20.0 Nodes TOP nodes

Environment Edit TOP node

Edits the variables set in the environment work item command lines execute in.

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Since 17.5


Each work item keeps a list of environment variables that should be set in the environment the work item’s command line runs in. These are stored as work item attributes with a $ prefix on the name (for example, $REPO_DIR).

The list of variables gets passed down from parent to child items down through the network. This node lets you edit the environment variable list of the work items passing through the node.


Generate When

Determines when this node will generate work items. You should generally leave this set to “Automatic” unless you know the node requires a specific generation mode, or that the work items need to be generated dynamically.

All Upstream Items are Generated

This node will generate work items once all of the input nodes have generated their work items.

All Upstream Items are Cooked

This node will generate work items once all of the input nodes have cooked their work items.

Each Upstream Item is Cooked

This node will generate work items each time a work item in an input node is cooked.


The generation mode is selected based on the generation mode of the input nodes. If any of the input nodes are generating work items when their inputs cook, this node will be set to Each Upstream Item is Cooked. Otherwise, it will be set to All Upstream Items are Generated.

Reset Environment

Clears the incoming list of environment variables (don’t inherit the list of variables set on the upstream items).

Add Variables

Use this multiparm to set up the environment variables to add/set in the outgoing work items.

Variable Name

The name of the variable to set, not including the $ prefix.

Variable Type

The data type of the value. Note that this is only used internally for the work item. In the execution environment, all environment variables are just strings.

Existing Name

What to do when there is already an exported attribute with Variable Name.

Replace Existing Variable

Replace the variable if it already exists, even if the type does not match.

Keep Existing Variable

The old exported attribute is kept and no values are modified.

Update Existing Variable Value

Overwrite the existing elements in-place, does not remove unaffected elements. If the existing variable is a different type, the value will not be updated by the Export flag will still be set on the attribute.

Generate Warning on Type-mismatch

When the existing attribute has a different type, generate a node warning and does not change the attribute.

Generate Error on Type Mis-match

When the existing attribute has a different type, generate a node error.


The value to set the variable to.


EnvironmentEdit Example for Environment Edit TOP node

This example demonstrates how to modify the environment variables using the Environment Edit TOP. Envrionment variables are special attributes with the Export flag set on them, which makes them available in the environment of out-of-process work item jobs.

See also

TOP nodes