Talk:Opacity

Soul sand?
Isn't soul sand transparent? It has 9/10 height of usual blocks, much like farmland. Xeoxer 14:00, 28 February 2012 (UTC)
 * Soul sand is not transparent. Sort of the same way a fence positions things higher than it appears, soul sand positions them lower, but the block of soul sand occupies its entire cube visually and thus there is no need for Minecraft to consider it a transparent block, because it would never have to render anything through its block. --Munin295 04:00, 7 November 2012 (UTC)

TNT?
"TNT is transparent." Following to the wikipage about TNT, TNT is not transparant. I tested this and the light level reduces in a building made of TNT. TNT is not transparant –Preceding unsigned comment was added by 119.4.250.97 (Talk) 07:53, 11 July 2012‎ (UTC). Please sign your posts with
 * Confirmed (v1.4.2): TNT is not a transparent block. I'll change it. --Munin295 05:01, 6 November 2012 (UTC)
 * Actually, it may be more complicated than that. Looking at Orthotope's code decompilation summary, TNT, the block, has an opacity of 255 (like stone, etc.) and thus stops the propagation of light. But tnt, the material, has isTranslucent set to YES and isOpaque set to NO (incidentally, glowstone has all the same values). So there's actually three different values which define a block's "opacity". This is probably worth exploring/explaining in the Opacity article sometime, but I think elsewhere the term "opacity" should just be used to describe the propagation of light level (because that's what most players care about), so TNT should still be considered an opaque block. --Munin295 17:28, 7 November 2012 (UTC)

Comparators and Tripwire Hooks
It looks like this page hasn't been updated in a while, as comparators and tripwire hooks aren't on the chart of types of transparent blocks even though they are transparent. 50.47.89.63 05:52, 1 May 2013 (UTC)


 * On a similar note, it appears cobwebs have been overlooked. --Quartzmmn (talk) 03:29, 29 September 2013 (UTC)

About Redstone Block and TNT
"At first sorry for my bad english (I'm BR)

Theses blocks are transparent, but its partial. We need to create a new category in Types of Transparent Blocks, I think."

-Gerottinho 00:41, 27 July 2013 (UTC)
 * For the moment, I've just added them under "solid blocks". Contra Munin above, transparency is not just about blocking light, and there are other blocks which block light but otherwise act like Minecraft transparent blocks.  We probably do need a better discussion of the components of transparency:  Munin above cites isTranslucent, isOpaque, and the "opacity" of light transmission, and the texture itself is a fourth. --Mental Mouse 13:01, 27 July 2013 (UTC)

There are different types of transparency so should we have a special name for each
Blocks can be see-through (transparent) or semi see-through (translucent) which is one type of transparency like glass. Blocks can be so Steve will fall through them without resistance and so he will with resistance that is another type like torches or signs or buttons on the side of a block. Blocks can also not support other blocks to an extent like torches or redstone or signs; an example is glowstone and glass to an extent. ~ LABHOUSE (LH) 17:54, 19 August 2013 (UTC)
 * Aside from the four items I cited above (perhaps Munin can properly describe what each does), you are adding the issue of collision boxes, especially the difference between full and partial blocks. In fact, torches, redstone, saplings, etc can "support" other blocks just fine, but they themselves can only be attached to certain blocks, with individual restrictions by type (solid/opaque/full, dirt/farmland, top/sides, and so on).  --Mental Mouse 12:59, 20 August 2013 (UTC)


 * LABHOUSE, you are basically correct. There are block "behaviors" that are primarily associated with transparent blocks, but then exceptions get coded in that blur the definitions. Here are some behaviors that are associated with opacity:
 * rendering -- when the game renders the block, does it completely block rendering of everything behind it? Some blocks are transparent, allowing background to be seen through them, while others are partially opaque (like stairs), blocking part of the background and not the rest.
 * light propagation -- some blocks transmit light fully, some partially, and some not at all. Further compounded by the fact that some blocks (e.g., air, glass) treat sky light slightly differently than block light.
 * suffocation -- "opaque" blocks suffocate mobs while "transparent" blocks do not.
 * mob spawning -- mobs can spawn on "opaque" blocks, but not on "transparent" blocks. Interestingly, mobs can spawn on hoppers even though hoppers transmit sky light unchanged (maybe the condition has been changed to a solid upper surface?).
 * grass growth/death -- complicated.
 * chests opening -- can't with "opaque" block above
 * leaves growth -- leaves can replace "transparent" blocks when trees grow (is this still the case? I'm not sure).
 * fence/wall configuration -- will connect to "opaque" blocks (I believe this may have changed to a solid side condition?)
 * door orientation -- doors will try to position their hinge side next to an opaque block when placed.
 * particle drip -- water/lava particles will drop from opaque blocks under water/lava (I'm not sure if this is still the case)
 * cutting redstone dust -- "opaque" blocks will prevent redstone dust from connecting vertically diagonally.
 * block attachment -- "attachable" blocks (torches, buttons, etc.) can be attached to opaque blocks only (there are a lot of exceptions to this "rule"!).


 * I think a good project for someone would be to expand the list of transparent blocks to clearly describe all these behaviors and which blocks are exceptions. Those exceptions should also be listed in the individual block articles (as I did recently with [//www.minecraftwiki.net/index.php?title=Redstone_Lamp&action=historysubmit&diff=516607&oldid=510469 redstone lamp]).


 * &mdash;Munin295 &middot; Grid_Book_and_Quill.png Grid_Stone_Pickaxe.png &middot; 17:54, 20 August 2013 (UTC)


 * Munin, apparently you have source access (which I don't) -- perhaps you could sort out which characteristics depend on which block flags? --Mental Mouse 14:39, 21 August 2013 (UTC)


 * I don't, sorry. Just things I've observed and discussions I've had with others who do have access. Orthotope's block decompilation is especially interesting -- there are three separate flags for opacity: block opacity, material isOpaque, and material isTranslucent (these are decompiled names, so no way to be sure of their actual intent), but these alone aren't sufficient to explain some exceptions, so there must be "hard-coded" exceptions.
 * &mdash;Munin295 &middot; Grid_Book_and_Quill.png Grid_Stone_Pickaxe.png &middot; 16:10, 21 August 2013 (UTC)

Transparency behavior is ... complex
I was doing some experimenting, and as of 1.14, the transparency behavior rules don't seem 100% consistent from block to block. I propose a new page that uses tables and such to go into detail about the placement of each block, what blocks can be placed on others, how they behave with redstone, etc. You can see some of this complexity at Java_Edition_1.14/Transparent_block_changes. Thoughts? -PancakeIdentity (talk) 00:03, 26 May 2019 (UTC)