[MC-295680] Lightning renders incorrectly from certain angles

The rendering of lightning bolts isn’t completely correct, and some interior planes are not rendered even though they should be. The outermost plane always renders as expected. It seems likely that this is due to a simple calculation error in the lightning bolt rendering code.

Conversely, when one plane renders behind another, the two are added together even though it would look much better if only the brighter of the two planes was rendered (and the brightness of the inner planes was increased, with the central shaft being fully opaque or nearly so). This is likely a change request, but it’s something to consider when fixing the main bug.

In normal gameplay, these issues don’t really interfere with anything but often remind the player that “yeah, transparency rendering is kind of buggy in Minecraft“. Issue #1 here seems like low-hanging fruit, and picking it would be a small step towards making the game feel more polished.