b3dPickedNZ

Returns Z component of surface normal at pick hit point from last pick operation (0.0 if no hit). Takes no parameters. Returns normal Z component (Double) from g_lastPickResult.normal.z. Reads result from last b3dCameraPick, b3dEntityPick, or b3dLinePick call. World-space surface normal Z component at intersection point.

This function retrieves hit normal Z. Pick sequence: (1) Call b3dCameraPick/EntityPick/LinePick to perform ray-cast, (2) Call b3dPickedNZ (and NX/NY) to get surface normal components. Surface normal: unit-length vector perpendicular to surface at hit point (for sphere picks: vector from sphere center to hit point normalized, for box picks: face normal, for polygon picks: triangle normal or interpolated vertex normal). Use cases: (1) Impact orientation (align bullet impact decal to surface), (2) Reflection (reflect projectiles off surface using normal), (3) Collision response (apply forces along normal direction), (4) Lighting effects (calculate surface lighting at hit point), (5) Physics simulation (bounce objects off surface). Common pattern: if b3dPickedEntity() > 0 then nx=b3dPickedNX(), ny=b3dPickedNY(), nz=b3dPickedNZ(), orient decal to normal. Typical usage: retrieve surface normal after successful pick (entity > 0), use for aligning decals or calculating reflection. Normal properties: typically unit length (magnitude=1.0), points outward from surface, perpendicular to surface tangent plane. No hit: returns 0.0 if no entity picked (check b3dPickedEntity first), normal is undefined if pick missed. Result storage: g_lastPickResult.normal populated by pick functions with surface normal at hit point. Performance: O(1) read (simple global variable access, instant). Related: b3dPickedNX/NY retrieve X and Y normal components, b3dPickedX/Y/Z retrieve hit position, b3dPickedEntity checks if hit occurred, b3dCameraPick/EntityPick/LinePick perform picking.