turn off lights in render mode

[cekuhnen]

we now have the new self illumination material - great

light designers will like it

but rendering lights in Fusion is hardly possible because you cannot turn off the env light in Fusion.

the only option you have is to set the env exposure to negative 3 and that still adds too much light.

what one really needs for this is the ability to simply turn the HDRI IBL off.

currently that mode is anyway not very useful because we cannot use our own HDRIs.

[hutchij]

 Adding this to the backlog. 

Just a note that adjusting the exposure does not affect the scale of the IBL, it only affects the tone mapping that is applied after rendering. So this will really not help. I've captured 3 enhancements: 

- allow turning off IBL in the render workspace

- allow users to specify custom IBL

- allow specifying a scale for IBL (this is also needed in the context of user-supplied IBL, since we can't know their absolute brightness)

John

[hutchij]

Hey all,

In the July release you can: 

1. Control the intensity of IBL. This is specified in terms of the resulting Illuminance (in Lux). See here for typical values. https://en.wikipedia.org/wiki/Lux  So if you want to evaluate the effect of emmisive materials, you can take the IBL intensity down to <1000 lux. In my examples below, there is both an LED strip on the drone as well as an accent light, (up and right of the camera) . For typicaly 
2. You can now specify custom IBL. We noticed that very large IBL (>6k pixels in width) will get downsampled in a naive way that creates some blocky artifacts. In my example below, I'm using a 300 MB IBL which is 16k in width and  has this problem. I was testing with an IBL from http://noemotionhdrs.net/ . They have very nice high resolution IBLs! Check it out.
   You can workaround this downsampling issue with the cloud renderer, we will fix the local renderer asap with a hotfix. 
3. In the next scheduled Fusion update we will add the ability to flatten the ground and position it more easily. 

Here's an example with the IBL completely off

Here's another example with the IBL illuminance set to 300 Lux.  You can see the effect of downsampling the IBL in the interactive raytracer. 

Finally, here is the equivalent cloud render which works well with arbitrarily large IBLs.