2.0/2.1 Significant SPS loss with water

Comparing the performance of Chunky `2.0beta4` vs Chunky `1.4.6beta2` performance is expectedly lower however, the extent by which water affects the SPS in `2.0beta4` is somewhat alarming.

For testing purposes, I generated two superflat worlds in both `MC 1.12.2` and `MC 1.13.2` and placed a single block of glowstone at `0, 6(?), 0` and two blocks of stone to provide some shadow. In Chunky I set the camera at `0, 50, 0` and `-90, 0, 0`; Emitters on and at 1000, postprocessing none, CPU load to 50%, and RayDepth to 25 (otherwise default settings).

I then made two renders of both the `MC 1.12.2` world and `MC 1.13.2` world; one without water world enabled, and one with waterworld enabled[note1]. Below are the renders and the results...

**1.4.6beta2 no water**

**1.4.6beta2 water**

**2.0beta4 no water** (See s1.4.6beta2 no water)

**2.0beta4 water** (would take too long to fully render... stopped at 8 SPP)

| | Render Time | SPS |
|-------------------|-------------|-----------|
| 1.4.6beta2 no water | 3m41s | 2,955,200 |
| 1.4.6beta2 water | 13m51s | 788,364 |
| 2.0beta4 no water | 4m32s | 2,408,004 |
| 2.0beta4 water | ETA21h | 8618 |

[note1] This behaviour is not exclusive to the use of water world. The loss of SPS has been observed in many different cases.