Caustics & Sunlight issue

[Jpjapers]

Hi, I was doing some experimenting over the weekend with trying to achieve some more natural lighting setups and I started playing with the caustics in the glass material I had in my windows.
It wasn't the result I expected and I'm just wondering if this is how it should look or if there's some issue with showing sunlight through caustics at the moment?

I've attached four images.
Two images use a hdri and have caustics on/off and the other two show corona sun/sky system with caustics on/off.

As you will see with caustics enabled, the shadows are a lot nicer in terms of falloff but don't have that direct sunlight sort of look to them.
Perhaps this is what should be expected? Can someone in the know chime in with any knowledge? :)

Thanks

J

[sprayer]

why do you need caustic for windows? It will be not visible in most case, also for some windows it is better even to disable refraction for speed up rendering.
The caustic for your scene should be on the street side depend of material setup, but with no production caustic in corona it will be almost not visible especially with sun light

You may check this info
https://coronarenderer.freshdesk.com/support/solutions/articles/12000043584-how-to-render-caustics-

[Jpjapers]

why do you need caustic for windows? It will be not visible in most case, also for some windows it is better even to disable refraction for speed up rendering.
The caustic for your scene should be on the street side depend of material setup, but with no production caustic in corona it will be almost not visible especially with sun light

You may check this info
https://coronarenderer.freshdesk.com/support/solutions/articles/12000043584-how-to-render-caustics-

I know i dont need it i was just curious as to its effect. Whatever the issue it makes such a big difference to shadows its obviously a visible effect even if its just a light transport or sampling issue.
Surely all glass has some level of caustic effect and since corona is using full path tracing for it it should be pretty accurate albeit time consuming to solve fully.

If its enabled and the flat glass object is 4mm thick like double glazing glass usually is, then in my mind the renders should appear at least similar.
My question is still why does the sunlight not look as intense as the non-caustic version of the glass as my setup is a real world setup.

[pokoy]

Did you set MSI to 0? If not, light intensity will be clamped at 20, which is maybe what happens here.

[Jpjapers]

Did you set MSI to 0? If not, light intensity will be clamped at 20, which is maybe what happens here.

I did not. Ill do that now and see what happens.

[Jpjapers]

Ok I did three very quick tests (attached)
one at default MSI 20, One at 0 and 1 and 100. I think the MSI was the issue.
Its still alot nicer than without caustics. the shadows are nicely softened. But currently setting msi to 0 isnt a production feature. Hopefully in the new solver in v4 things might clean up a little quicker!

[pokoy]

Yes, with MSI at 0 the caustic version should produce the same result as the one without caustics, I guess. If it renders long enough to be clean, that is.

[Jpjapers]

Yes, with MSI at 0 the caustic version should produce the same result as the one without caustics, I guess. If it renders long enough to be clean, that is.

Good to know anyway thanks!