DH_REF
float dz = sqrt(1.0 - (DH_REF*DH_REF + DV_REF*DV_REF) * (0.5 + 0.5/Z_CUT_RATIO) * (0.5 + 0.5/Z_CUT_RATIO));
fGeometry.xz_max = (0.5*DH_REF)/fGeometry.z_max;
fGeometry.zoom_factor = (float)dh*(fDepthRef/DH_REF);
dx = fCamera.Axis(0)*(DH_REF*0.5);