A ridged-noise heightfield (1 − |noise|, sharpened by a power) raises a range of sharp crests, and 65,536 GPU particles stream along the ridge tangents — perpendicular to the surface gradient — like wind combing a mountain spine, lifting to the ridge altitude so the range stands up in 3D. Colour rises from cool valleys to warm peaks; drag to steer the ridge angle, drag vertically to sharpen it, press to shift the palette.