Engine:

• add sop level lights: sop/areaLight, sop/ambientLight, sop/directionalLight, sop/hemisphereLight, sop/pointLight, sop/spotLight. The goal is to provide a set up similar to Houdini's solaris, which allows:

  • to move and lights proceduraly, using the copy sop for instance
  • to easily switch and try out different light rigs
  • to easily import light rigs from another scene

• obj/blend: set frustumCulled depending on updateOnRender param.

• sop/attribCopy: fix bug where it was not possible to copy from P to instancePosition

• fix bug in rampParam where removing a point could generate an inconsistent ramp