IBL - Corona Light vs Skylight

[Aliastasia]

Hiya :)

I was wondering whether anyone could help me?

I am currently exploring Corona with a scene utilising a sIBL set, created from the freebie set from VizPeople.com.
When you run i.e the sIBL-scanline import script, it sets a skylight with an environment IBL as texture in the middle of the scene-setup it generates, with the sun targeted at the Skylight, so they move in tandem. (and yes, I have set them to use CoronaShadow)
However, as Corona recommends we use native lights as much as possible, is there a workflow to generate a similar effect using Corona Lights?
What I am getting now when I put a map - TGA or HDR onto the CoronaLight, is just a bright, bright visible light no matter how much I turn it down that just leaves a black hole when Visible Directly is unchecked.
Or is the best way to just ignore that particular workflow alltogether, and solely use the sIBL _bg.TGA-file  as environment/direct override and then slap the HDR into the Corona Settings> Environment>Use Corona slot, and then just generate a shadowcatcher material from scratch by hand?

Thanks for any feedback - curious as to whether the sIBL default setup is of any benefit in Corona at all.

Enclosed - Image with the different setups

[Ludvik Koutny]

Jesus christ! Do not ever use geometry sphere to light your scene! :D

That's over 10 years old workflow! Just put the map you have mapped on sphere into 3ds Max's native environment slot, and set mapping mode to spherical environment.

Also, do not use sIBL! It's super old tool designed to create quasi-hdr environment set up back in times where correct rendering was still not mainstream. Simply either put HDRI map into environment slot, or put just non-HDR spherical bitmap into environment slot, and then align CoronaSun angle with it. :)

It scares me that someone still uses these super legacy workflows :D

[CiroC]

Can I use this topic to inquiry what is the best way to set the camera? What I am doing now is creating a balance between the F-Stop and shutter speed to get good light even if the HDRI in the background goes over-bright.

Thanks

[Aliastasia]

Be scared all you want - the sIBL scripts are actually a fairly fast workflow when you're on a pipeline, and most of the time, you can, oh, I don't know, tweak the scene to get rid of the superfluous components. Also - the spheres don't render, you know that, right? 
The HDR files themselves get loaded into a RaySwitcherMat which is put into the environment slot in MR, and just the *TGA background plate if it's scanline, and HDR as a skylight.
In addition - running an HDR-file through the sIBL editor actually gives you three plates for the price of one, pretty fast, so I guess our opinions will just have to differ ;-)

Moving on back to my question - one of the reasons I started exploring sIBL in Corona, bar converting from a scanline-script import, was that I am having problems linking the sun to anything, in addition to the perpetual glow of the Corona Light
Is the sun utterly untargettable - bar linking and manual tweaking, and is there a way to get rid of that superglow in the Corona Light when having an HDR mapped to it, as few other lights in Max do that in my experience,  or do you just have to use the standard Max lights and set them to CoronaShadow?

Here's how a default Maya-Env raySwitcher is set up, just so we're clear it's not rendering spheres ;-)

[Ludvik Koutny]

6 years ago when was the last time i used sIBL in Softimage, the sphere WAS used to illuminate the scene. It changed moved since then, but it still promotes bad workflow.

In corona, you do not need to set up network of overrides and blurred env maps for GI to get good results. Actually with proper HDR, you should not even use any sun object, because sun disc should be already captured in HDR file (assuming it was captured with correct bracketing)

Now to your question. Create Daylight system in 3ds Max, set Sun to CoronaSun and sky to none. And set control mode to manual. Now compass will act as target, and sun will be always looking at that target.

Now i have no idea what you mean by superglow. It can be either intensity, direct visibility or visibility in reflections, and all of these parameters can be directly toggled in CoronaSun.

[Aliastasia]

Ah - 6 years ago.
It's common knowledge things stay static over that amount of time ;-)
As for the MR-shader - are you familiar with MR?
Because Corona's, even though it only has four nodes to connect,  - looks a little similar to MR's RaySwitcher material. But you're totally right, the network of nodes IS smaller!

Sometimes you have to work with what you're given by your client - that includes bad maps with bad bracketing. So - this is why one sometimes uses sIBL, this is why one has workarounds, like i.e the sun.
A lot of times people ask things not out of ignorance, but because it's where they are in their work-process or pipeline.


However, thank you for the daylight tip - I was trying to follow recommendations I read elsewhere and met a wall after taking a wrong turn, so that totally helped :-) 
As for the glow - I think I'll just hash it out on my own, but thank you :-)

[Ludvik Koutny]

Well, there should not be any network of nodes if you wanna use image based lighting in corona properly.

Especially those gamma nodes are crazy. 3ds Max is not Maya, it has correct linear workflow for several years now. One should never feed anything through any kind of gamma node.

My usual workflow is that if i get spherical map with bad bracketing or even jpeg, i simply orient it the way i want and then align my sun to the sun on the map. That's all. Really, if you want to use image based lighting in Corona, then simply put your spherical environment map in the environment slot. That's all you need to do. And then use CoronaSun aligned with the map to boost HDRIs with bad bracketing or 8bit spherical maps.

You should also keep in mind that fakes in Corona often negatively impact performance. So not only legacy workflows give worse looking output, but they also often harm performance.

[Aliastasia]

Thank you - I will take it into consideration.

[romullus]

Moving on back to my question - one of the reasons I started exploring sIBL in Corona, bar converting from a scanline-script import, was that I am having problems linking the sun to anything, in addition to the perpetual glow of the Corona Light
Is the sun utterly untargettable - bar linking and manual tweaking, and is there a way to get rid of that superglow in the Corona Light when having an HDR mapped to it, as few other lights in Max do that in my experience,  or do you just have to use the standard Max lights and set them to CoronaShadow?

You can easily link CoronaSun to whatever you want: