IES (Photometric Lights) with Maxwell. How??

[nzjimmy2001]

Hey guys

Can you use photometric lights with Maxwell? I tried but it doesn't seem to see them at all. I know my scene scale is correct so its not that. There is a tutorial at Evermotion called "Real IES in Maxwell" but this doesn't help because it doesn't actually even use IES lights. Can anyone help me out?

[bricklyne]

Maxwell doesn't support IES light formats. The Evermotion tutorial is basically a work-around. It was originally supposed to support IES but like displacement, fast speed, procedurals, and a whole host of other announced/promised features for version 1.0 it never actually made it into version 1.0.

 

You're best bet is to wait for version 2.0 (or maybe 3.0, or maybe 4.0, 5.0?........) whenever that shall be, and when the so-called rs2 engine (if it actually even exists) is implemented to stand any chance of getting anything like IES support in Maxwell.

[AJLynn]

Actually I have a nagging doubt that IES is possible with Maxwell. Lights need geometry - there's a combination of shooting and gathering, and both need to happen for it to work correctly, and point sources don't cooperate with gathering. A hack would be needed (like sunlight - and we saw how that worked out with caustics).

[leoA4D]

Hmmmm. No IES and Maxwell is the "Light Simulator".

[bricklyne]

Actually I have a nagging doubt that IES is possible with Maxwell. Lights need geometry - there's a combination of shooting and gathering, and both need to happen for it to work correctly, and point sources don't cooperate with gathering. A hack would be needed (like sunlight - and we saw how that worked out with caustics).

 

 

Actually, I think it should be possible with the Maxwell engine methodology (MLT-type simulation), just not with this current variety of their render engine. IES is basically the geometric representation of light dispersal patterns, which as you correctly alluded to, is heaviliy dependant on the geometry and configuration of the light source. But along with this there are other factors that influence the light dispersal patterns such as the refractive/reflective effects of the light source geometry, which in turn determine the caustic patterns that are distintinctive of specific IES patterns. These patterns are the ones that are then simulated and/or replicated, but as we all know, Maxwell (rs0 and rs1 anyway) has serious problems when it comes to resolving light caustics through glass.

 

So yes, a hack might be necessary to overcome this hurdle otherwise IES light sources would make Maxwell rendertimes go from excruciatingly long to plain ludicrous. They did after all have to hack solutions to hiding objects from the camera, architectural glass, and IES would be no diifferent IMHO. All you have to do is consider the fact that you currently have to keep your light source geometry down to very basic and simple geometric shapes to have them light at all and essentially to realize that IES is not coming any time soon. But the fact remains that with MLT methodology IES should by all means be possible.