Object renders but lights don't in Arnold Render View

[Anonymous]

Hey,

I'm 3 months into Maya (with half-arsed guidance from my teacher -- I'm mostly self-teaching) and trying to put Arnold materials, specifically chrome, onto some objects.

To do this properly I need to have my lights working in Arnold Render View, and Arnold Render View displays my object fine, but won't pick up the Maya area light (not Arnold area light) I've got in front of the object. I've upped the exposure into the thousands, no change. My object renders smooth shades with a black background, and seems to be picking up other lights that were already included in my file -- I didn't set those up and they were made before my camera was. I don't know if there's some kind of connectivity issue between light-camera-Arnold, but I can't find any info on that either.

 Any help would stop my growing insanity with this software.

[mspeer]

Hi!

- Make sure the light points in the right direction.

- Increase Intensity or Exposure further if necessary.

- If you want the Light source itself to be visible: "It is not possible to make Arnold lights visible to the camera. However, the Ai Mesh Light does have a 'Light Visible' option."

[Anonymous]

Thanks mspeer. The light is pointing in the right direction, I've upped and downed exposure too -- I'd notice even a slight change on the Arnold Render but there's none at all (I'm also updating the render view. It recognises distance changes, but no light. Meanwhile I've illuminated my object so much in Maya it's just a white box. That's where I think the problem lies -- Arnold Render isn't picking up the light I've created at all.

[mspeer]

Hi! Please upload a scene-file.

[Anonymous]

Here's the scene. I was given a pre-modelled/lit scene. Most of the lights, one of the cameras were already in place. The camera (TV_cameraShape1) and Area Light set up I'm trying to render is in front of the TV. (I added that camera and area light specifically to assign materials to the TV.)

[mspeer]

Hi!

1. Your light has a negative scale

2. You changed Maya default units to "m" don't do this, leave it at "cm" and treat as meter, or you need much higher values for your light output.

[Anonymous]

Hey, I was hopeful that'd be the fix, but I set my light scale to positive 400 and it still won't render in Arnold. (The units of measurement were preset in the file, I didn't change those to meter, but switching them to cm doesn't affect the render anyway. The lights are still a no-show in Arnold render.)

[Stephen.Blair]

From the Arnold log:

ignoring parameter intensity on areaLightShape1 (found bad float: 9.99999979e+33) 

Lower the intensity and exposure And the negative scaling is confusing, because the area light icon looks like it's pointing in the wrong direction

[mspeer · Accepted solution]

Hi!

Don't set Exposure to such a high value.

Please read the Arnold for Maya User Guide and learn how exposure works.

Start with Intensity "20000" and Exposure "6" or downscale your scene.

[Anonymous]

It worked! Thanks. Reading up on the Arnold exposure, it makes so much sense now.

[Anonymous]

Thanks for pointing out the Arnold log, will check that out for any other problems.