surf_puff

Cumulus puff surface for the cloudsurf part. Spheres are displaced into lumpy billows in the vertex stage (noise_amt, animated by breathe + game_t); the fragment wrap-lights them with a warm sun side, cool underside, crevice pooling and a silver-lined rim, then fades toward haze_color with distance. alpha below 1 enables a fresnel edge fade for translucent wisp materials.

Used by surf_tower_mat / surf_tower_far_mat (opaque distant towers) and surf_wisp_mat (transparent near-field wisps).