you may know that Thea can handle sun pool caustics with its unbiased TR2, which was in fact the subject of an older tech announcement. It was a sad thing though that TR1, a superb unbiased render engine, could not resolve sun pool caustics. For those that are not familiar with the subject, let me say here, that the so called "sun pool caustics" is a particularly difficult lighting transfer to solve with unbiased rendering. This is why it has not been addressed by the vast majority of other commercial unbiased renderers.
The sun pool caustics are such so strong visual cues, that we definitely wanted to see them resolved by TR1 as well. Rendering nowadays an exterior scene with a pool missing caustics, would not make the render look convincing (this is why some users had actually used TR1 and TR2 combined to get fast exterior rendering with the caustics included).
Thus, I am very happy to present a solution to this problem, with TR1 being able now to resolve this lighting (with a restriction*). This makes possible now to render exteriors with these visual cues (much) faster than TR2. Also a requirement for us, not to have any speed penalty in other scenes rendered with TR1, is satisfied. This is why this addition is a win-win enhancement in all cases.
* Restriction: the water surface must have zero roughness.
File comment: Sun pool caustics rendered with TR1 in the standard example scene that comes with Thea, in 15 minutes on quad core machine.
TR1_Sun_Pool_Caustics_15min_quadcore.png [ 657.36 KiB | Viewed 2490 times ]
File comment: Exterior scene rendered with TR1, sun pool caustics included (image kindly provided by "Javadevil").
Pool_TR1_Caustics_01.jpg [ 120.29 KiB | Viewed 2490 times ]