Mental Ray not rendering lights

[Anonymous]

Hi all, I'm new to Maya and I've been trying to render a scene with Mental Ray, but my lights are either super dim or not showing up whatsoever. They render fine with Maya Software, and I've dug through Google to find a solution, but I haven't come up with anything. I adjusted the light intensity, size, imported the whole scene into a new scene, rescaled the entire scene, created new lights entirely (they are only three area lights), and none of it worked I haven't assigned new materials to everything yet, if that makes a difference. Attached is a screenshot with the Mental Ray render in the corner- does anyone have a solution for this?

Edit: Forgot to mention that I'm using Maya 2016.

[damaggio]

Turn on Final Gather, make sure your lights are inside of the sphere( looks like one light is being clipped by the sphere}, make sure light is pointing down.

Your second light pointing up is not gonna work, try to rely on the bounce light from FG.

[damaggio]

And remember that the scale of scene affects the lighting, if scene is very large you will need to increase the intensity to a very high value.

[Anonymous]

I made the light that was going through the sphere smaller so it wouldn't intercept it, but it didn't change anything, and I double checked that all of my lights were pointed down (and they were, unless I'm missing something major?) Each of the smaller lights are at 250 for intensity, and the large overhead area light is at 500. I tried turning on Final Gather, but the lights still don't show up. For reference here's a screenshot of the rendering with Maya Software (with Illuminates by Default selected for all lights) vs the Mental Ray rendering with Final Gather enabled (with Illuminates by Default unselected for all lights). Am I just supposed to make a new object incandescent to replace the lights?

[damaggio · Accepted solution]

250 intensity might be very low, you might need 2500000 to illuminated but then again i don't know the scale of your file...if u want you can zip your scene and upload here.

[Anonymous]

I was just fiddling around with it and increased the intensity of the lights 10x, and that combined with Final Gather seemed to work. Thank you for your help!

[damaggio]

Great am.tuel, good luck with your project then.

[mspeer]

Hi!

I'm a bit confused. First, at your first screenshot it looks  that the lights point upwards, the small line on the area light points to the ceiling.

Second, why do you turn off "Illuminates by default" for your lights when rendering with Mental Ray?

Could you please upload a "light" version of your scene with all lights, the sphere and at least 1 floor object.

edit: no need for an upload when the problem is solved.