Hi, guys!
It's that time of the year when someone somewhere has to b*tch about Corona caustics rendering, and here I am! :D
This topic stems from the fact that I have to create a set of indoor house CGIs for a wealthy client who will also have an indoor pool in his basement. And, to no surprise, I ran into big problems trying to make the thing look convincing. But that's a story for another day.
I was wondering what people's thoughts are regarding the lack of caustics in Corona in general? I personally think it takes away a LOT of realism in scenes with metals, glass and reflective materials in general, ESPECIALLY if they're a focus point (I still remember writing stuff near a window as a kid and how the sun would hit my fountain pen's nib and produce beautiful caustic patterns - something that's not possible in Corona without slowing it down to a grind ATM).
I'm attaching a couple of very simple renderings of a scene to illustrate the difference. The setup is the same for both: a "pool" mesh with SOLID water geometry (water geometry that actually does have sides and the bottom, a closed mesh, displaced at the top) and a Corona sunlight. The water material has caustics enabled as does the chrome material of a piece of tube to the right. Nothing fancy. The ONLY thing I changed between the renders is the engine: default PT+Cache vs PPM (Progressive Photon Mapping). I must add that while a lot more realistic - the PPM engine is super slow and never really converges into a noiseless picture, so can't be used for projects as it is.
The difference is crazy, in my opinion. And it bugs me that something like this has been ignored for so long :(
As a photographer who photographs interiors I understand that caustics can actually be irritating (I sometimes have to photoshop weird caustics reflecting on the ceiling caused by spotlights shining down on metal parts of furniture, especially in bathrooms), but it's all there in the real world and should be an option in Corona.
Thoughts?
EDIT: If caustics is not possible without photon mapping in Corona (like Iray and the likes that have caustics enabled at all times pretty much) - maybe an option would be to add an option to pre-calculate a photon pass for caustics, similar to how Redshift/Mental Ray/VRay do it? I could live with that, as long as it can eventually be used to generate sharp, detailed caustics.
« Last Edit: 2016-11-23, 13:59:27 by Rimas »
![](https://forum.corona-renderer.com/Themes/Skm_Light_RC5/images/ip.gif)
Logged
A morning of awkwardness is far better than a night of loneliness...