Time  Nick        Message
01:29 muurkha     haha
01:41 muurkha     sparky4: I see you got back to your dorm
03:16 wsor4035    !tell wsor4035 test
03:16 MinetestBot You can tell that to yourself
03:16 wsor4035    good
03:17 wsor4035    !tell shaft assuming that you agree to behave and learn from this, we will unban you one week from now for a second chance
03:17 MinetestBot wsor4035: I'll pass that on when shaft is around
08:03 copygirl    So when I define an entity with use_texture_alpha enabled, for some reason it looks like there is still a cutoff at 50% alpha or something? Part of the model ends up being completely invisible, rather than semi-seethrough.
08:04 copygirl    https://i.imgur.com/hsq1tet.png
08:08 copygirl    Here is the full model visible with an opaque texture: https://imgur.com/Rk7gkim.png
08:10 MTDiscord   <rollerozxa> by texture_alpha enabled, do you mean you've set it to "blend"?
08:11 copygirl    That's for nodes. It complained when I tried to use "blend" for an entity.
08:11 copygirl    According to the API, entities have `use_texture_alpha` that's just a boolean.
08:12 MTDiscord   <rollerozxa> oh I see, you're talking about an entity not a node
08:13 MTDiscord   <rollerozxa> hm, I'm unsure if semitransparent textures are even possible in an entity then if use_texture_alpha wouldn't work for it
08:16 copygirl    It *does* work it's just cut off past a certain point for some reason.
08:16 MTDiscord   <rollerozxa> yes, sounds like alpha clipping behaviour
08:19 sfan5       in other terms: for entities you chave the choice between "blend" (true) and "clip" (false)
08:19 sfan5       dunno how well semi-transparency even works however
08:43 copygirl    Oh it's a year-old bug? #10032
08:43 ShadowBot   https://github.com/minetest/minetest/issues/10032 -- Entity translucency is still broken
08:47 erle        that sounds like an easy fix
08:48 erle        copygirl looks like a one-line-fix, how about you make a PR?
08:49 erle        like cut it off at 1/256 or so
08:49 copygirl    The cut off should be at 0 for alpha blended entities.
08:50 copygirl    I don't touch C++ though.
08:50 erle        it's a constant WHAT CAN POSSIBLY GO WRONG :D
08:54 copygirl    Me touching C++ is what could go wrong.
08:54 copygirl    I'm not touching game engine code besides my own.
10:10 MTDiscord   <luatic> sfan5: in theory, semi-transparency works by rendering semitransparent triangles in the correct order (back to front)
10:10 MTDiscord   <luatic> in practice, we don't do that, but I think we render entities that are farther away sooner? (entities are distance sorted)
10:13 MTDiscord   <luatic> so semitransparency across different entities should work, but semitransparency across different faces of the same entity (as in sorcerykid's example), or across entities / nodes / particles won't work
10:14 MTDiscord   <luatic> (it gets even hairier if you want(ed) to properly deal with the "edge case" of intersecting triangles; then you'll have to split up triangles)
10:15 MTDiscord   <luatic> solving this efficiently is hard. perhaps the easiest solution would be some form of "order-independent transparency" (i think Multicraft does this?). implementing this inefficiently in software rendering is easy (basically go from a single texture + depth buffer to a sorted set of colors + depths per pixel), but I don't know how one would implement it efficiently in GLSL.
10:17 MTDiscord   <luatic> a naive "triangle sorting" approach isn't really an option; it would greatly complicate the code and probably be way too inefficient. for example you might have to break up mapblock meshes.
10:21 sfan5       don't we have working semi-transparency for mapblocks already? why can't this solution be applied to entities?
10:35 MTDiscord   <luatic> sfan5: for some definition of "working", we do. but AFAIK there's (1) no mesh-interior semitransparency support (2) no support for particle-mapblock / entity-mapblock semitransparency.
10:37 MTDiscord   <luatic> IIRC what it did was (1) sort the mapblocks (as we already do for the entities), (2) change the meshgen to produce different meshes depending on which direction the mapblocks are viewed from, such that (some?) faces are properly sorted
10:38 MTDiscord   <luatic> what we'd have to do for semitransparent entities is effectively sort the triangles of the mesh based on their distance to the camera (z-sorting). special cases (like the cube drawtype) can get simpler solutions.
10:40 sfan5       ah okay that makes sense
15:06 MTDiscord   <warr1024> "<copygirl> I'm not touching game engine code besides my own." <-- besides, having to depend on a fork of MT to make your mod work correctly would kinda defeat the whole purpose of using MT in the first place...
15:09 erle        Warr1024 well you can add a PR after that right
15:17 MTDiscord   <warr1024> I suppose that PRs are still theoretically a thing, yeah.
16:05 copygirl    @luatic: To be clear, I'm not running into a sorting issue here. NodeCore has few semi-transparent elements and my arrows would render on top of opaque blocks. Water is unlikely to be involved either. The renderer simply throws away pixels that have <50% transparency.
16:15 MTDiscord   <warr1024> NodeCore has historically avoided use of semi-transparent anything specifically because of the known issues with them at the time I started the project, and I haven't started to rely heavily on the improvements since then either.