Can I achieve this look with Renuva or Sculptra? I've been told I don't have enough fat for other options. (photos)

the result that you are looking for will cost you alot and it is not easy to achive it, I would actually recommend you try lipo with buttock, or butt implant. 

For the look you provide it would be too costly to use Sculptra or Renuva. I would entertain fat transfer but that will not be enough to get you the contour you seem to be hoping for. In all honesty even an implant would need to be coupled with fat grafting or another technology to even approach that look.

Dear Pau,Fat Transfer is a wonderful way to add volume to the buttocks and extra curves.Liposuction of your left and right lower back and transfer to the buttocks would give you a lot more volume, than 10+vials of Sculptra.Choose an expert.Best. Dr Brecht Seattle, Wa