Physics support glitch.

When constructing a structure that requires several supporting pillars (Say, a large bridge) - it becomes a rather huge problem where one region of support meets another.
At the maximum 'overhang' - 5 blocks I believe - it doesn't matter at all if you have another support waiting beneath the structure, as newly placed blocks seem to run a single check for available support, and if that check turns our false in any one case, the entire block becomes unstable.
This is hard to explain without a diagram so..



Here, there is no support for the block and it falls as expected.



However... when support is added from the right side... it has no effect!

The block only checks for support on its left side, first, and when that fails - the entire block fails.
The blocks need to run a check for support in ALL directions, and look for any passed checks, rather than just stop at the first failure.
(at least this is how I picture the coding works at the moment - if support fails, stop checking, etc)

In trying to work around this problem and creating monstrous bridges, I've also run into -strange- glitches, where some of these blocks placed in odd locations either:
Turn invisible
Make that area unusable
Are placed as gold tile (WTF?)
Become grass/dirt

Something funky is going on where these regions of support/no support interact.

 

Once I was playing on some bridgy map (bilbs server?) and deleted some support blocks of the bridge to replace them with new ones, I created some strange blocks, like new type of gold block containing 50 gold :) or the earth background 'block' (this thing that stays on the wall after digging the earth block) - this one made that area unusable.

 

It didn't fall when you added support from the right side... because you added support from the right side.

If you have no support for 5 blocks in one direction, the 6th block you place will fall.
But if you have support coming from the other side, your structure will stay up.

Either you didn't understand the physics system at all, or I didn't understand what you were doing because pictures alone can't explain the glitch.

 

Ew nighthawk, he built a second pillar which hits the ground on the right side, and when it was only one block space between the structures, he couldn't place a stone tile into it. And there were support enough. I think that the pictures fully explain it.