Adjust the lights AFTER RENDER and then comes the FINAL Magic:
With a push of a button re-adjust all the light’s intensity inside Blender with the settings you have played with the rendered image !
Go straight to 1:18 of the video:
And also this is an old video from 2016 and did not show what has been implemented in the new versions, which is the ability to send those settings right back to the program and reset those lights to match !
The VRay company bought out Corona, I always suspect they bought it for its speed and THIS technology, this is the holy grail, after acquisition, VRay 5 finally have this LightMix technology.
This technology is so amazing…imagine…just put the same amount of lights as the real archviz lights and put them at their exact positions, render…never mind the light intensity.
Now that it’s rendered…relax and adjust the lights without the crazy CPU running like crazy in the backend.
And when you are done with how the light looks, send the light intensity settings back and re-render to get maximum accuracy.
This is so far out I suspect Blender would not have this technology for a looooong time, I say 5 years in the future.
Not sure if you are joking or this is serious… anyway - implementing that is somewhat easy (each ray gets an additional light-id on its journey through the scene)
Its just that nobody needs that anymore since we have responsive realtime viewports.
Last time this was useful was with maxwell renderer more than 10 years ago
Hmm…I appreciate your reply but…I don’t think you get it, Corona Renderer have that which you have just mentioned as well…but I don’t blame you, this workflow is hard to explain to those who have never experienced it.
Hmm…Even if the implementation of real-time viewport, it’d still be a nice additional feature to have something that can offer more flexibility for the Cycles render engine like what Corona is having here…
You know - you can do this workflow yourself without any programming right now in blender:
disable tonemapping, (standard instead of filmic)
Render each light separately (manually its a bit of work depending on the scene, but usually you wont go above 10 lights)
save as hdr / exr
load and stack the layers in photoshop with ‘linear dodge’ blend mode
Now you can adjust the lights by layer opacity exactly like in the video. In terms of ‘math’ it is the same. The only thing you loose is tone mapping (which can be done in photoshop, but not as nice as filmic)
ps: if you just stack jpegs/tiffs with 8/16 bit the exposure will be wrong - this only works reliably in 32 bit
My instinct is right, you are more knowledgeable than you would reveal yourself to be on your first reply.
What you say is true, but ready for the magic ?
1: We are not just talking opacity here, you can INCREASE the lights intensity as well !
2: The alpha and omega, with a click of a button, those intensity settings can be send back to the 3d program, the lights will all be updated to reflect their new intensity.
yea point 2. involves a bit of math - i mean you could do it:
multiply the light by the exposure value from the compositor and you get exactly the right result - but its a bit of a hassle
As Alair says it’s easy to do in Cycles and Eevee currently. Thing with lights is as their intensity increases the pattern of what they light due to GI does not change. For point 2. This means a light can be rendered at a moderate intensity then multiplied with its own image to get that light to be brighter than what it was to begin with or easily reduced to zero. I remember experimenting and being able to change the color as well. There is even a 3rd party program that does a little more calculations and is more of black magic which can change the textures of any surface after the render and have it look like that texture was there when it was originally rendered.
Everyone of you here are a gift, you are all so gifted in your understanding and knowledge.
The resending of the data back so that the light have the newly “corrected” data is because you can only post process so much before the noise factor creeps in, no if or butts about it it will happen especially when the intensity is on the increasing side instead of the decreasing side.
That is the magic in Corona, that all these and more is done…in.one.click.
Light passes are coming in the (not too distant) future: actually some work in the past was made in render passes code exactly for paving the way to this and AOV, and a patch already exists. You can even look for some builds on graphicall (https://blender.community/c/graphicall/kdbbbc/).
I doubt the implementation will get as far to let the recalibration of lights intensities with the press of a button though. Maybe that could be more a job for some clever addon.
: 