2.0/2.1 Underwater Emitters don't illuminate blocks correctly

[jackjt8]

Underwater emitters do not illuminate blocks and only illuminate the water surface. I have yet to test other conditions.

Expected results (1.4.6beta2) -

Results from 2.0beta2 -

Credit to Lohfrum_Faleign for discovering this.

[jackjt8]

I have now tested with the camera above the waters surface, with the emitter being below, and I am seeing the same issue.

[vis 20, opac .1]

Expected results (1.4.6beta2) -

Results from 2.0beta2 -

[llbit]

I tried to reproduce this in 2.0-beta5 but it seems like a glowstone emitter works fine underwater.

[jackjt8]

It appears my initial assessment of the problem was incorrect. After testing 2.0beta5 in real time I noticed that emitters do in fact emit light but it is significantly reduced in both amounts and intensity. This prompted additional testing at 16SPP.

For a camera which is submerged (test 1), it's not just the emitter which are seeing diminished effectiveness, but also the sunlight itself. In the case of the camera being above the water (test 2), sunlight appears to work as normal but the issue with the emitter remains.

Test 1
1.4.6beta2

2.0beta4/5

2.0beta4/5 (increased brightness)

Test 2
1.4.6beta2

2.0beta4/5

[jackjt8]

I also decided to generate another 1.12 world with an Ocean Monument and port it into 1.13. I matched the settings otherwise- This time having emitter intensity set to 1000, but I'm certain the same is true for sunlight, I will just test that in a second.

1.4.6beta2

2.0beta5

[jackjt8]

And finally just some testing of the sun light under water. Intensity set to 5.

1.4.6beta2

2.0beta5

[llbit]

Thanks for the update, I'll continue to investigate. Could you upload the scenes for Test1?

[jackjt8]

Test_1.zip

Certainly. I've also provided the original worlds just in case you would want them.

[jackjt8]

Did some additional testing and noticed that for non-flush light sources underwater light propagates at least 1 block in each direction like it does in 1.4.5. Also noteworthy that in this scene, the underside of the water surface is not being lit in 2.X.

1.4.5

2.0beta6