# Symmetry and Symmetry local

Symmetry and Symmetry Local are useful for simulation of symmetric bodies.

Symmetry local mirrors existing body at an arbitrary selected flat surface (which I understand) but Symmetry local mirrors existing body at either X+Y, Y+Z, Z+X planes (which I also understand) or X, Y or Z (which I don't understand)?

Also, when using symmetry, does the all forces sum up, i.e., does drag and lift monitor for the rotating wheel example (which use local symmetry) show 50% or |00% of total drag, lift of the wheel?

### Symmetry Planes Definition

Conditions->Symmetry (distinct from Conditions->Symmetry Local) on the Physics Tool Palette mirrors the 3D View Window in various planes relative to a coordinate system. X is the X=0 plane, Y is the Y=0 plane, and Z is the Z=0 plane. X+Y mirrors both X=0 and Y=0, as shown in section "Use Symmetry to View the Entire Simulation" in the tutorial "Incompressible Flow Through a Pipe into a Box".

Symmetry does not change the force or any other sum-based variables. For the symmetrical wheel tutorial the drag and lift are 50% of the totals for a full wheel.

### Symmetry

Thank you for the explanation, it was very helpful!