@dave r said:

How are you planning to show the resulting image to the client? You could do something with layers, scenes and stacked viewports in LayOut.

Thanks for the reply. The idea was to let the county planners (when applying for building permits) see right away which parts were new and which were existing. So, this will just be a single image in a pdf file for the county. I'll try fiddling with the textures as you suggested.

I'm using SU Pro 2017 to make a model of an existing house and a proposed addition. I'd like to be able to make the existing part of the structure grayed or dimmed (similar to the effect you get with fog), but leave the proposed addition looking normal. Is there a way to somehow "dim" a group of objects, or maybe an entire layer?

I've tried adding color by layer to a style, and making the existing structure gray. That sort of works, but the rest of the model has whatever funky color was assigned to it (so none of the textures for the roof or siding show up). I suppose I could post process images in Photoshop, but it seems like there should be a better way.