Building an island by hand in Studio's terrain editor takes hours. Studio can import a whole landscape from two images instead - a heightmap (bright is high, dark is low) and an optional colormap that assigns a material per pixel. This makes both: generate a base with noise, sculpt it, paint a mask and re-generate inside only that mask, then let the materials assign themselves by elevation and slope. Nothing is uploaded; it all runs in your browser.

How it maps to Studio. One heightmap pixel is 4 studs, so the region size below is derived for you. Colormap pixels are matched to Roblox's material colour key, and every pixel is snapped to an exact material value on export - Roblox's docs warn that anti-aliased edges produce colours between two materials, so nothing here ever blends a colormap edge.