SPLINEBOOL_AXISΒΆ
| SPLINEBOOL_AXIS_NONE | No axis. |
| SPLINEBOOL_AXIS_SCREEN | Project into the current screen. |
| SPLINEBOOL_AXIS_ZY | Project on the ZY (X axis) plane. |
| SPLINEBOOL_AXIS_XZ | Project on the XZ (Y axis) plane. |
| SPLINEBOOL_AXIS_XY | Project on the XY (Z axis) plane. |