Don't want photometric light discs to be seen in mirrors

reserv888

When I render with photometric lights in IRAY the discs are seen in mirrors.

How can I fix that?

JimmyC_2009

Have you tried the Parameters pane, Display > Rendering > Invisble in Render?

maclean

JimmyC_2009 said:

Have you tried the Parameters pane, Display > Rendering > Invisble in Render?

Ha! If anyone can get it to work, please let me know.

reserv888

JimmyC_2009 said:

Have you tried the Parameters pane, Display > Rendering > Invisble in Render?

Yes I have, but if I do they don't emit light.

Tobor

When you take a picture of a mirror you see what's reflected in the mirror, including lights. Iray is that way, too. You can hide the emitter from the camera for direct view, but it doesn't work on light that is reflected or diffused through a marerial. Being a physically-based renderer, this is how it's designed.

That said, there are some work-arounds if you want to hide the lights from the camera. None are as simple as a switch, but they can work depending on the circumstance. One method is to activate the Iray Matte feature for the mirror, which then renders a transparency there. You'd composite a regular version of the mirror where you'd turned off that light.

For more info on matte objects, see: http://www.daz3d.com/forums/viewreply/830499/ (the thread is about a different aspect of matte objects, but the instructions on activating the feature is the same).

For the light-less version of the mirror, you can just re-render everything this time with the light off, or if you know how to use Iray Canvases, select just the mirror as a node, and render it out separately. There are various descriptions of using Canvases in the forum. It's not hard, but there are several steps involved.

 

SickleYield

Turn off Render Emitter?

Tobor

Render Emitter looks promising for this, but it turns out it works only for direct view -- light source to camera lens, and nothing between. If the light is reflected, or shines through a gemoetry, the emitter is then shown. I imagine this is Iray's simplistic way of dealing with the use cases.

Of course, the behavior could be changed in 4.9, as it uses a newer version of Iray. Worth a check.

Joe Cotter

Professional photographers recognize this as one of the bigger pains in the (insert word here) in photography. There is no reason that the lights cannot be hidden from the camera while still emitting light as there are other physically based render engines that don't have this restriction. I hope this is changed in IRay at some point as I see no function in it. There are many tricks that professional photographers go through to light a scene that "isn't natural" to give the lighting they want/need for a shot. To force people in a 3D environment into the same machinations makes no sense.

As to a fix, consider rendering the image with and without the offending lights then combine the images in post to get the final image you want. It's not a great solution, since the image has to be rendered twice, but if the render time isn't too high it would work.

Tobor

If you know canvases and light path expressions, it can actually be done in a single render pass. But you're right that there should be some more options here. The obvious ones, like limiting ray traces, also adversely affect other aspects of the scene.

scorpio

Gedd said:

...

As to a fix, consider rendering the image with and without the offending lights then combine the images in post to get the final image you want. It's not a great solution, since the image has to be rendered twice, but if the render time isn't too high it would work.

 

It might be possible to just render the area effected as a spot render (in new window) rather than the whole image.