erosion_heightmap_gn_cpu gained an erosion_scale parameter (proc-nodes 5a3f88a: the slope must be in the units of the gullies it steers, not in M_TH). Both ProcNodesBridge::evaluate call sites now pass owner_->erosion_scale_ — the same value that reaches the shader as EN_ESCALE via wp.en_erosion_scale. These two must move together. sample_density answers collision queries while the shader draws the surface, so a divergence is a player falling through ground that is visibly there. gate_dc_vs_lookdev demonstrated it concretely while only the GPU side had the fix: 7.921 m max disagreement, with the gate's own control still discriminating so it was not a false alarm. With both sides moved it is back to 0.002 m.