Hello,
I'm working on a TerrainInteraction. Since you click on the ground to activate it
(and not on a sim or on a object) it doesn't have an icon (in the interaction queue
at the top of the screen). I added a IMAG resource and tried to override some
method in the interaction definition to use it but so far with no success.

Any suggestions?

You need to implement both IOverridesVisualType and IHasCustomThumbnailIcon interfaces in the InteractionDefinition class, then return VisualTypes.CustomThumbnail for the first implementation and the code to retrieve the thumbnail for the latter

P.S. The Sim parameter used in GetCustomThumbnailIcon is the ActiveActor (i.e. the Sim you currently have selected while playing), not the one from the InteractionDefinition (if you're using one).

EDIT : I forgot to mention, the above is for the Pie Menu, for the InteractionQueue you need to override the GetIconKey method in the InteractionInstance class. As it is it retrieves the icon from Target, but you can change it to anything you like.

Thanks! You missed my relentless questions, didn't you? ^^

The system you suggested allows to change the little icon on the pie menu, I love
that and I'll use that, but I meant the icon in the queue at the top of the screen ^^

You missed the part where I tell you how to change that one :p

Yep, totally missed the edited part. It worked, thanks again.

You're welcome