Lights in my sceen are not working right

[Anonymous]

Hi

First of all I am using Maya 2018 with Arnold MtoA 2.0.2.4

So I have this problem with the lights in my sceen. I have a spotlight with no decay. To be able to see the light in my render window I have to crank up the intensity to 10.000. That is not normal especially when there is no decay on the light. Also, the exposure setting in the Arnold tab are grey. I have no idea why that is but it might have something to do with it. 

First I thought it was because my sceen size was so big but the biggest object in the sceen is 405cm

This is what I see when I import the light without changing the intensity. Note that the exposure and radius in the Arnold tab are grey.

And this is the render, the light is not doing anything.

When I crank the intensity up to 10.000 it looks like the render will be blown out and way to bright.

This is the render with intensity set to 10.000. Not working right because it should be blown out.

And this is the size of my sceen. I thought that was messing it up but it turned out its not.

I have tryed to make a new sceen to test this but this always happens. If anyone could help me out I would be very grateful.

[mspeer · Accepted solution]

Hi!

Arnold works different than Maya or Mental Ray when rendering lights.

1. Arnold is a physically (only) based renderer. It simply ignores the Decay setting. For a better preview in Maya set Decay to Quadratic, or use an other renderer.

2. "Also, the exposure setting in the Arnold tab are grey"

This Attribute is set to non-keyable,  it will not be keyed when using hotkey "s".

This extreme light grey is new since Maya 2018 (hope they make it a bit darker with next update).

3. For better control and quality of Arnold lights use:

- Exposure (also available in Camera)

- Radius

- Normalize

Please read the Arnold for Maya User Guide for more details.

[Anonymous]

Thanks 😉

[loganfoster]

While I get that this in theory "fixes" the problem, I certainly hope that the Maya or SolidAngle team will fix this problem as this so called fix makes the viewport completely useless for setting up your lighting correctly and IMO makes working with Arnold a lot harder than it should be.

Either Arnold needs to apply some kind of multiplier to Maya standard lights when its set as the active renderer, or the Maya team needs to find some way to have a "I'm using Arnold" setting for the viewport so that the lights do not overpower and wash out what is displayed to the user in the viewport.

[Anonymous]

Yeah totally agree with you.

[mspeer]

Hi!

Every Renderer uses different formulas for calculations + the Viewport does not know what renderer you want to use + the Viewport uses it's own engine to Hardware Render the scene. So there will be some differences. (Keep in mind that some renderers have their own tabs inside some nodes and use these features and values for rendering. Other renderers, like the Viewport, can't use this values)

Although i commit that there are some things that could be optimized for better preview in Maya, i don't see a problem with default lights.

Looks pretty similar: