User:Munin295/Projects/Opacity

The purpose of Project Opacity is to research and describe the anomalies of block opacity/transparency.

Research
For each block which is not obviously opaque, conduct the following tests:


 * 1)  Sky light propagation
 * Discussion: A truly transparent block, like air or glass, will not reduce the illumination level of sky light 15 from above -- if the block above the test block has sky light 15, then so will the test block. Other non-opaque blocks (e.g., leaves) will "diffuse" sky light, reducing its level by 1.
 * Test: Build a "cubbyhole" of stone consisting of a 1x1 floor with three 1x1 2-block-high walls next to it and a 1x1 ceiling. Stand in the cubbyhole, block yourself in with a single block of dirt at feet height, and place the test block on top of the dirt at head height. If the F3 sl value is 14 (not 15, because you're standing under the cubbyhole's ceiling), the block does not diffuse or diminish sky light, and should be marked as Transparent. If the F3 sl value is 0, mark the block as Opaque. For any other value, mark the block as Semi-Transparent and note that it diffuses sky light.
 * Notes: Be aware that we are testing the propagation of sky light, not sun light, so it doesn't matter if you do your testing in the day or at night. For some test blocks you may need to modify the set-up to allow the test block to be placed (e.g., placing sugar cane will require water next to the dirt block), or to prevent fluid spreading into your own space.
 * 1)  Block light propagation
 * Test: Build a cubbyhole (as above), place glowstone two blocks above the dirt (leaving a one-block space between them), and place the test block on top of the dirt at head height. If your F3 bl value is 13 (you're two blocks away from the light 15 glowstone), then mark the block as Transparent. If the F3 bl value is 0, mark the block as Opaque. For any other value, mark the block as Semi-Transparent and note the total amount of block light it diminishes (i.e., 14 minus your F3 bl value).
 * Notes: For some test blocks you may need to modify the set-up (e.g., block light will melt ice, pop mushrooms, etc.).
 * 1)  Suffocation
 * Test: Build a cubbyhole (as above), and position a piston so that it will move the testing block into the cubbyhole at head height. Stand in the cubbyhole and activate the piston, so that your head is now in the testing block. If the block causes suffocation damage, mark the block as Opaque, otherwise Transparent.
 * Notes: Some blocks cannot be pushed by pistons; mark these blocks as Untestable.
 * 1)  Mob spawning
 * Test: …
 * 1)  Grass death
 * Test: …
 * 1)  Chest opening
 * Test: …
 * 1)  Leaves growth
 * Test: …
 * 1)  Fence configuration
 * Test: …
 * 1)  Door orientation
 * Test: …
 * 1)  Particle drip
 * Test: …
 * 1)  Wire cutting
 * Test: …
 * 1) Circuit attachment
 * Test: …
 * 1) * Redstone torch
 * 2) * Button
 * 3) * Lever
 * 4) * Pressure plate
 * 5) * Tripwire hook
 * 6) * Redstone dust
 * 7) * Redstone repeater
 * 8) * Trapdoor
 * 9) * Rail

Results
Record the result of each test: O for Opaque, S for Semi-Transparent, T for Transparent, U for Untestable. If there are any interesting details, describe them in the Notes column (for long notes, use tags to link to them below).

When a block's tests have all been completed, do the same for the conclusion: O, if the row is all "O"s; T, if the row is all "T"s, otherwise S (ignore "U"s).