Switch between HDRI environments using a key

Question

In my workflow I use two environments (hdris) plugged into a mix shader. I use one HDRI to light up the scene and the other HDRI to create materials. I switch between them using the factor parameter in the Wrorld Properties.

I would like to know if it is possible to somehow map a key that would switch between these two hdris? For example pressing A would active the first HDRI and pressing A again would activate the second HDRI and so forth.

Answer 1

Tricky way

Well, actually you can do it without scripting:

Add a new item in key map in window section, operator is wm.context_toggle, attribute is scene.world.node_tree.nodes["Mix Shader"].inputs[0].default_value, where "Mix Shader" is the node name. Your node might have different name, check that do you have in here:

Operator way

The more proper way is to do the operator. This is the script that I made from simple operator preset:

import bpy


def main(context):
    node_tree = context.scene.world.node_tree
    input = node_tree.nodes["Mix Shader"].inputs[0]
    input.default_value = 0 if input.default_value == 1 else 1

class ToggleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "wm.toggle_update"
    bl_label = "Toggle Operator"
    
    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        main(context)
        return {'FINISHED'}

def register():
    bpy.utils.register_class(ToggleOperator)


def unregister():
    bpy.utils.unregister_class(ToggleOperator)


if __name__ == "__main__":
    register()

    # test call
    bpy.ops.wm.toggle_update()

Your node might have different name (not "Mix Shader"), check that do you have in here:

This script creates operator. You can set it like this in keymaps:

To make this script works across files, you can save it as .py file and install as an addon. In this case, you should add addon info block.