McNeel.SdkPlugInLoadTime

SummaryDiscusses how to configure plug-ins to load at startup.

Question

How to I set my plug-in to load at startup?

Answer

Rhino will load plug-ins in two ways.

When Needed (Default). Plug-in will not be loaded when Rhino starts. Plug-in will be loaded when a plug-in defined command is run, when a user selects a plug-in defined file import/export type, or if a 3DM file has user data that was created by your plug-in.
At Startup. Plug-in is loaded when Rhino is loaded and initialized.

To set your plug-in to load on startup, you need to override your plug-in object's CRhinoPlugIn::PlugInLoadTime virtual function and return CRhinoPlugIn::load_plugin_at_startup.

Note, if you have already loaded your plug-in using Rhino's plug-in manager, when debugging for example, then you will need to either remove your plug-in's registry key, which can be found here:

  HKEY_LOCAL_MACHINE\SOFTWARE\McNeel\Rhinoceros\4.0\<rhino_build_date>\Plug-Ins\<your_plugin_guid>

or you can just modify your plug-in's "LoadMode" registry key value. The available values for this key are as follows:

Load mode	Registry Value	Description
load_plugin_when_needed	2 - REG_DWORD, Decimal	Default. Load the first time a plug-in command used
load_plugin_at_startup	1 - REG_DWORD, Decimal	Load when Rhino is loaded

The reason this step is required is that the "LoadMode" Registry key value is only written the first time the plug-in is loaded (when it is initially installed or registered). This will not be an issue for customers of your plug-in for the correct registry key value will be written the first time they load your plug-in.