So far I was using a mesh with an alpha blend shader to show explosion blasts on the floor (see bellow) but as I now have elevations, it just looks wrong if it happens on a slope.
So I decided to use a projector instead but I can't get it to look right. Using the same texture than before (with the standard asset shadow blob shader), I obtain something like that:
It seems to be an issue with the alpha map but I can't figure it out. Any idea ?
Hard to know - projectors are tricky to work with. One thing you can try is to set texture wrap more to clamp. But I doubt that is your problem in this case.
The texture looks pretty grayscaley, so I would use a multiply blend mode instead.
I realize this is half a year old, but it just showed up in the RSS feed. I'm voting to close as no longer relevant, as the OP still only has 1 reputation; I doubt he'll be back.