I am a VFX artist with experience using Pixar’sRenderman / Arnold / Vray / mentalRay ( back in the day ), and testing a lot of render engine for personal interest.
I want to use blender as my daily driver 3D application for all my personal work, and I can get around a lot of its uniqueness, and actually like most of the UI decision made since 2.8.
But as a lighter with now 10 years experience, I have a really hard time not having a dedicated dome light in Blender.
The issue is not about Cycle, but the fact that there is no Dome/Env light objects at all.
My understanding is that, in Blender, if I want to light a scene using an HDRI ( not matter the render engine used ), the only way is to plug the HDRI in the world slot, and I need to use a math node if I want to expose up or down this HDRI in blender.
Using a world slot to do Image Based Lighting is, IMO, a very old way to approach environment lighting, and this should be addressed in Blender.
All render engines I know are now using dedicated dome/env lights, the world slot for HDRI died with MentalRay and probably a old version of Vray as far I can remember.
To explain why we need Dome Lights in modern lighting workflow, I will give some examples :
1 - Sky is a light :
Environment lighting using an HDRI or a Physical sky should be treated as a light in the UI.
Most renders use a dome light for the exposure and sampling control of this specific HDRI in the dome lights parameters. So its’ hard to create a plugin for blender, if blender ignores the fact that most render engine use dome lights.
2- Multiple dome lights for more control :
A lighting workflow we use sometimes, is to actually have 3 HDRI contributing to the beauty, for example we have one dome light for the sky, one other dome light for the ground, and one for the sun ( keyed out from the sky HDRI ). This allow us to have more control other exposure of the ground / sun / sky while using image based lighting only, which is better than a directional light when using PBR shaders. We also use multi light AOVs, to be able to adjust those exposure in post>
3-Light linking :
We sometime want to have a specific HDRI contributing to a specific piece of geo in one passe ( for example, eyes of a character, or windshield of a car ).
I take the liberty to open this topic because I did a lot of research and I was very surprised that I could not find any topic discussing this.
Please let me know if this request is out of topic in blender development forum.
Thank you for taking the time to read this.