I'd love to have 3D barriers and smoke clouds to use in Heroclix (1/48 or "O" scale), but nothing good seems to be commercially available. Who would you considered making some? They don't seem as though they would be particularly difficult compared to some of the other things I see here. And I bet I'm not the only Heroclix player who'd be interested in buying them.
Their bases would need to be 1.5 inches squares (the size of the squares on a Heroclix map) . Smoke clouds would need to be able to fit around figures because those can be used on squares occupied by characters. But the barriers could could be solid and occupy the entire 3D space.
Based on the various characters who have the power to generate barriers in the game, likely designs include:
Green Lantern barriers (you couldn't use the GL emblem of course, but a greenish brick wall would work)