Adding Transparent/Opacity mesh/sprite depth?


Need some guidance on how to achieve this goal; I basically want to have textures that are used to create ‘islands’ but avoid using terrain (detail/complexity not needed) and aren’t completely flat. A couple of ways I have tried doing this is firstly to create a sprite from the texture using the translucent lit sprite material, then shrink wrapped collision around the islands. Looks good, the problem is since it is a sprite it is a completely flat plane… can’t find any info on this and would assume it is not possible to extrude any depth through any trick/conversion? I need the islands to ‘sit’ in the water. So instead I have tried just making a box mesh, adding the texture for the material colour and hooking up the alpha to the opacity mask. Again, looks good but flat as a pancake despite the depth of the mesh. I would also need collision to map the material texture somehow even if I successfully get depth set up. I could just model it but I seem to be almost there and it would take longer potentially, any help would be appreciated. This is from a top down perspective so doesn’t need to be viewed from the other side, so maybe a combination of them for a sprite surface and a z-axis hollow mesh?