OTOY Forums

Chris wrote:The IES emitter material is supposed to be assigned to a sphere instead of a plane or any other object. It won´t lit the scene correctly if not assigned to a sphere.

Chris

Can You give us some proof because I was testing them on planes and I think they are quite good...

With spheres, you must use the pitch/yaw/roll orientation.
With planes or discs, you can orient it by you 3d-app, which is much better and can be animated...
But i has read that Roland wrote, spheres are better supported.

face

face wrote:With spheres, you must use the pitch/yaw/roll orientation.
With planes or discs, you can orient it by you 3d-app, which is much better and can be animated...
But i has read that Roland wrote, spheres are better supported.

face

great info.. thanks face and Roland

A sphere will indeed give the most accurate reproduction of the distribution.

An emitter on a plane without an IES distribution has a radiation pattern with the highest intensity in the direction perpendicular to the plane, gradually falling of to zero in directions parallel to the plane. If you add an IES distribution, this distribution will modulate this radiation pattern, so the distribution will be attenuated for directions far from the normal of the plane. This will be most noticeable for very wide beams, but I think narrow beams will still look OK.

face wrote:With planes or discs, you can orient it by you 3d-app, which is much better and can be animated...

This is not the case, Octane always orients the light sources relative to the world coordinate system, so you still need to orient the light source in Octane.

Ah yes, thats right, sorry.
I has some different results with an animated light, but that was because the lightdisc has deflected the light.

face