When a Native Revit RPCs are not compatible with the V-Ray Decalprojects onto an RPC, it renders onto the RPC's bounding box. To avoid this behavior, you can replace the RPCs with Cosmos assets or exclude the RPCs from the projection by creating a Revit model group including the Decal and the geometries you want it to project onto.
...
. Make sure they are excluded from the V-Ray Decal's projection.
