Lightshafts problems

[emanuele3d]

The Lightshaft effect is very nice and can make the environment quite spectacular. However, the current implementation has a few problem:

1. edges of nearby objects should not generate lightshafts
2. held in hand items (i.e. torches) should not generate lightshafts
3. player names in multiplayer should not generate lightshafts

This is due to lightshafts being generated out of an FBO that already contains first person view objects and multiplayer names. This problem can be solved by generating the lightshafts before those elements have been added to the view.

There could be exceptions to some of this, i.e. an environment that is foggy or smoky might have much more noticeable lightshaft due to the thicker air, dense with particulate reflecting the light. But as far as I know we do not have environmental data to read for this purpose.

[emanuele3d]

@Cervator: can you please assign this to me?

[Cervator]

@rzats beat me to it. I took off the Alpha 2 milestone though as I doubt this will be fixed during that soon'ish release :-)

There are some similar issues with reflections, like a held pickaxe may reflect on a body of water far in front of the player if held just right.

[Josharias]

There is still some work to do with letting MeshComponents pick when to draw. Specially in the case of held items that need to be drawn on top of the world. I would imagine that a mesh component could specify to draw in the first person layer.

[emanuele3d]

@Josharias: let's talk about it when the rendering engine re-architecturing is well underway. I wrote this lightshaft-related issue to make sure we store it somewhere, but I'm not going to have the chance to look into these issues any time soon. Is there already an issue about what you are talking about?

@Cervator: I think I know what you are talking about. Let's make sure that's also in an issue if it isn't already.

[Cervator]

I'm not sure there is an explicit issue for it, although I think I've posted a screenshot or two about it somewhere. Some mildly related issues: #1712, #747, #459

It seems to only happen in the experimental SSR mode, which may by why we haven't documented it deeper, likely leaving it till some general reflection refactoring happens. Here's a quick screenie just so we have one:

[DPirate]

It also seems like all you need to do for activating lightshafts is just look in the direction of light source.