diff --git a/content/programming/unreal-engine.tree b/content/programming/unreal-engine.tree index a2d0f72..9340adb 100644 --- a/content/programming/unreal-engine.tree +++ b/content/programming/unreal-engine.tree @@ -8,232 +8,12 @@ - both the fun and the good, and that which ruins my mood % id = "programming/unreal-engine/blueprint" -+ ### Blueprint + content.link = "programming/unreal-engine/blueprint" ++ ### thoughts on Blueprint - % id = "01H8Y0CKD1H9MFQ74ERYNQHF35" - + NOTE TO SELF: this section could really use some screenshots +% id = "01HP1FESY5WVJG4X80AZ4ZBX5D" +- ### random but cool things - % id = "01H8Y0CKD1QWDY8304APN69VG6" - - I don't have UE installed on my home computer yet, so you'll have to take my word for a lot of these things - - % id = "01H8Y0CKD1VENHWERX7CTGCE6M" - - anyways back to your regularly scheduled bullet points, *\*ahem\** - - % id = "01H8Y0CKD1QHMTGFCK2RC3NPDV" - + Blueprint, _my arch nemesis!_ - - % id = "01H8Y427AYC9SDK6SFSSEHH376" - - _WHAT! you don't remember me? how rude!_ - - % id = "01H8Y0CKD1NJPAH1SBNN5T9KQT" - - actually I really like Blueprint - - % id = "01H8Y0CKD1YPXAR8KH3JPCD3HW" - + lots of visual languages generally feel really unpleasant to write (looking at you Scratch), but somehow Blueprint feels like exactly the opposite - - % id = "01H8Y427AYWPYJHGGS63B7C8SN" - - (it's possible Scratch got better since I last used it like 5 years ago but I remember it being pretty cumbersome to use. - I had no reason to revisit it since so I simply don't know if it's any better now, but if it is, [let's chat][branch:hello]!) - - % id = "01H8Y0CKD1G06CG62XWZ02JREC" - + writing Blueprints is actually pretty darn nice and there's a lot to learn from the editor UX and basic refactoring tools - - % id = "01H8Y0CKD1G86TY8AF6Z2SQ85P" - + when you drag your mouse out of a pin, and a window will pop up giving you suggestions on what could be connected there - - % id = "01H8Y0CKD1P9SNK3TV967M705C" - + then you select from the list and it creates the node, autoconnecting stuff as necessary - - % id = "01H8Y0CKD1PQS2J2WB22ASZY17" - - one of the nicer autoconnections it can do is when you want to call a function on an actor component - - % id = "01H8Y0CKD16PFNWJ6EAARHA7BD" - - instance functions require you to pass in a `self` to call the function on - - % id = "01H8Y0CKD1FVPCA5NBY5KK1F5X" - - so what it does is it suggests functions to call on all the _concrete components - you already have in your actor_, and when you select something like `Destroy Component (DefaultSceneRoot)`, - it'll not only create a function call node, but also hook up `DefaultSceneRoot` as its `self` parameter - - % id = "01H8Y0CKD1KM42PKVSGB4QASG3" - + when you try to connect two pins of incompatible types, it'll automatically insert a conversion node for you - - % id = "01H8Y0CKD1NES5RBGVTPRH3F0Q" - - Blueprint is strongly typed so you can't just pass in a `Float` where a `String` is expected, but luckily this makes the system way less painful - - % id = "01H8Y0CKD10GQBNNP0RBJEWKW4" - - I do have a gripe with this though and it's where it places the node. it tries very hard to center it but unfortunately never succeeds. - - % id = "01H987QXFE445XNN5YDS2FYR5F" - + perhaps a bug I could fix one day? - - % id = "01H987QXFEYSE260S996BE84DV" - - from [Oskar Kogut](https://github.com/kretoskar): if you change a `BlueprintCallable` function to `const` (or otherwise make it pure,) the editor will automatically correct the `Exec` pin flow for you - - % id = "01H8Y0CKD1C5TJXXD40B99WQ3C" - + the design of Blueprint the Language is pretty dated - it is still an imperative language and has a concept similar to statements (`Exec` pins), which breaks the entire idea of pure data - flow and introduces control flow into the mix - - % id = "01H8Y0CKD1J2P2HZ507YBSNVKK" - - this split is called _pure_ and _impure_ nodes, where impure nodes are those that perform control flow (ie. those with `Exec` pins) - - % id = "01H8Y0CKD1P5JQCGHEY405KKPH" - + this results in weird edge cases like needing two separate node types to handle branching (one that can have side effects - `Branch`, and another that can't - `Select`) - - % id = "01H8Y0CKD1EGWTQYHT2WYQSZY5" - - `Branch` is used to shuttle control flow between two `Exec` lines, based on a `Bool`. you get a `True` branch and a `False` branch - - % id = "01H8Y0CKD1WFEWNYPZWGCH3N7X" - + and `Select` is used to choose a value based on another value, kind of like a ternary in C++ - - % id = "01H8Y0CKD156C0ZAXK7JS9W81D" - - however it is quite annoying because you can only switch on enums (and other stuff that has a finite set of values,) whereas with `Branch` you can use any `Bool` condition you want - - % id = "01H8Y0CKD1YP7Q3HVJJZNJAJKG" - + this would be fine if not for the existence of Gameplay Tags, which precisely _do not_ have a finite set of values - - % id = "01H8Y0CKD1P7D9QMPVQYWSDFT5" - - there is a `Switch on Gameplay Tag` node, but that is for control flow and not data flow! - - % id = "01H8Y0CKD126918N282MNBXD2C" - - this isn't an unsolvable problem but it illustrates the pure vs impure issue pretty well - you'd have to duplicate the implementation of `Switch on Gameplay Tag` to have - a version without an `Exec` pin - - % id = "01H8Y0CKD1N37WTCY66CM7R198" - + I'm seeing a bit of a semblance to the classic [function coloring problem][def:article/function_coloring] - - % id = "01H8Y0CKD19JMY87YY50M3RCQF" - + except where it usually applies to the `async` concept found in most modern programming languages, here it applies to the concept of control flow vs data flow - - % id = "01H8Y0CKD1Q8RXXK3KE4F4XAFF" - - and speaking of `async`, [Blueprint handles the classic `async` problem very gracefully][branch:01H8Y0CKD106HXQAJK87XV0H93]! - - % id = "01H8Y0CKD106HXQAJK87XV0H93" - + despite its flaws, one of Blueprint's strengths is asynchronous and latent tasks - - % id = "01H8Y427B03JNPTWW025ES176K" - - since control flow is based on those `Exec` pins, you can easily map your classic concept of callbacks to simply firing off the appropriate `Exec` pin - - % id = "01H8Y427B05AER1R4XK1GZ6A0M" - - for example the node for playing animations (`Play AnimMontage`) has a few pins coming out of it that signal playback events like `On Ended`, `On Blend Out`, `On Interrupted` - - % id = "01H8Y427B01SE52ZYA410QKWDQ" - - and you wouldn't even know these are implemented as delegates in C++landia. it just feels like a first-class feature - - % id = "01H8Y427B0V2Y76JJ3Z229PD15" - - the only gripe I have is that you can only have latent nodes in the main event graph (you cannot have them within functions) - - % id = "01H8Y427B0SPJ3NJCFS7S4YGR9" - - which is annoying but not terrible, since most of that latent, high level gameplay logic happens inside the main event graph anyways - - % id = "01H8Y96DGCWWTAP5X8ZYPCJZQC" - + the editor UI, despite [being helpful as it is][branch:01H8Y0CKD1G06CG62XWZ02JREC], is far from perfect - - % id = "01H8Y96DGCRP0W6YWJ3PYJ2GES" - - it's actually quite janky and there tend to be brief flashes of content falling into place - - % id = "01H8Y96DGDVZ4DZ4AZE7EDYNFP" - - this is true of other parts of the Unreal editor UI but I'll focus on Blueprint here - - % id = "01H8Y96DGDDRA8DD6PRGDCF8GP" - + node UIs are laid out lazily, by default using an algorithm that does not produce precise results for pin locations - - % id = "01H8Y96DGDT0Y23G86HEKNWF4H" - - which means that when you first load a Blueprint, some of the wires will be bent in weird ways, and will fall into place as you zoom out and explore the graph more - - % id = "01H8Y96DGDCEF6FEQWGX2BQ6AH" - - the effect looks quite janky and really upsets my inner perfectionist - - % id = "01H8Y96DGDJG41P3XTFE8F4Y1M" - + as you zoom out, the nodes start looking just a little bit different due to font sizes being snapped to integers - - % id = "01H8Y96DGDRCBKWBXC7AXZV43E" - - at very low zoom levels, nodes stop rendering their text altogether, which makes their layout shift even more. - - % id = "01H8Y96DGDGRBZXWH31G08FRYM" - - the effect of this is that nodes themselves take up less space, and it appears as though there is more space between them than there actually is - - % id = "01H8Y96DGD1QSAJ0QWD2ZYXKEW" - - which can make it frustrating to lay nodes out on a large scale, because you'll only find out your nodes are overlapping when you zoom in real close - - % id = "01H8Y96DGDSM03EJJVN9FS6SSB" - - there's a `Straighten Connection` feature, which you can use to make your graphs look more aesthetically pleasing, but it only straightens the nodes such that they look good on the current zoom level - - % id = "01H8Y96DGDNTKMGSJZDJN2GSJB" - - so what'll happen with it sometimes is you'll straighten a connection, then zoom in, and the connection won't be quite straight because of the aforementioned layout shift - - % id = "01H8Y0CKD1103FHF332M2Q4MG7" - + maintaining Blueprints in a large project could be a lot better - - % id = "01H8Y0CKD1PPEPX8EEFRAM2VE1" - + with regards to your graphs becoming really large - - % id = "01H8Y0CKD1DFSJ4BDPPFMGK66M" - - everybody kinda sorta just formats nodes however they see fit, and there is no unified autoformatter - - % id = "01H8Y0CKD1VRVNMZ827RF7XBCA" - - there's a reason people say Go's tooling is frickin' amazing, you know. it keeps codebases consistent! - - % id = "01H8Y0CKD1980VGHFBYGM8PN3E" - + this results in what we Hat in Time modders used to call _Kismetti_ in the Unreal Engine 3 days but nowadays we'd call _Blueprintti_ - - % id = "01H8Y0CKD179SBZ58F5JMDC5F3" - + which is a portmanteau of Blueprint and spaghetti. - - % id = "01H8Y427B0PJN75GA33S9CZJYH" - - I can't believe I remembered the spelling of that word. *portmanteau*. - - % id = "01H8YT7R15B3Z3T486DB53TR51" - - there are plugins on the marketplace that solve this, but I refuse to believe Epic Games doesn't have this problem themselves - - % id = "01H8YT7R15VTF7VPX5QK7K233J" - - I'd guess it's just not very high up their priorities - - % id = "01HA4HJKRVQ9GVMNY6NSY0T3T6" - - refactoring your nodes is a hell of a pain. Blueprint is kind of write-only - - % id = "01HA4HJKRVBSRB5T1GM0TBE1C7" - - say you're calling `ApplyGameplayEffectToTarget` a bunch of times and you want to replace those occurrences with a custom function that wraps `ApplyGameplayEffectToTarget` - with some extra semantic information, to make it more discoverable, searchable, and easy to use - - % id = "01HA4HJKRVGD7CW6T3MHRKNJS7" - - well then good luck :hueh: - - % id = "01HA4HJKRVBN3RR32Q9WHMKVFY" - - in a text-based language you could use a dumb search and replace to accomplish this task, but there is no such thing in Blueprint. :cry: - - % id = "01H8Y0CKD1QF5YBTKF3JEZCN5W" - + with regards to assets (how long this darn stuff takes to load) - - % id = "01H8Y0CKD1B1MZH39Z7EKB6KDT" - - the biggest offender here being that hard references are the default - - % id = "01H8Y427B17K7219TPH8VRFZ96" - - thus you can add a Mesh Component to your Blueprint and it'll load *the entire mesh with all the textures and skeleton and everything* when you wanna tweak a variable or some logic in the event graph - - % id = "01H8Y427B1QNZHJ5Z8W0QNFYPE" - - and not asynchronously in the background, you will have to _wait_ for it to finish loading. which is pretty annoying - - % id = "01H8Y0CKD16HEQKQX1NJG9GG42" - + the runtime performance isn't the best for a few reasons - - % id = "01H8Y427B1ZKJA16V17NG80QHS" - - the VM isn't implemented in the most optimal way - - % id = "01H8Y427B1JJD3EK24DCG76GR0" - - I've analyzed this in my [`dispatchers` repository][def:dispatchers/repo] if you wanna have a read - - % id = "01H8Y427B1T148Y0T8E48DKJ3N" - - and that hard reference thing can make gameplay stutter when you're loading in new assets, but that's a more widespread issue than just with Blueprints - - % id = "01H8Y427B15BD0HJWM2Y3EZBSZ" - - but in reality most of the logic you're implementing in Blueprints (high-level gameplay stuff) shouldn't be that performance sensitive - - % id = "01H8Y427B1G7ZYE3S8RRHG5WRQ" - - and it's not hard to extract the performance sensitive parts to C++ because Blueprint offers tools for refactoring your code - - % id = "01H8YT7R15MFW3RRQAF8CM4EP6" - - but all that doesn't prevent me from liking it! - - % id = "01H8YT7R15ZJWBY0TN6F6HN95Y" - - since it's way more pleasant to write game logic in than C++, given that you don't need to wait a minute for your code to recompile. + % content.link = "programming/unreal-engine/fixes" + id = "01HP1FESY5ZS6YTZXA8QTT5V1Z" + + data validation quick fixes diff --git a/content/programming/unreal-engine/blueprint.tree b/content/programming/unreal-engine/blueprint.tree new file mode 100644 index 0000000..1386ae0 --- /dev/null +++ b/content/programming/unreal-engine/blueprint.tree @@ -0,0 +1,229 @@ +%% title = "thoughts on Blueprint" + +% id = "01H8Y0CKD1H9MFQ74ERYNQHF35" ++ NOTE TO SELF: this section could really use some screenshots + + % id = "01H8Y0CKD1QWDY8304APN69VG6" + - I don't have UE installed on my home computer yet, so you'll have to take my word for a lot of these things + + % id = "01H8Y0CKD1VENHWERX7CTGCE6M" + - anyways back to your regularly scheduled bullet points, *\*ahem\** + +% id = "01H8Y0CKD1QHMTGFCK2RC3NPDV" ++ Blueprint, _my arch nemesis!_ + + % id = "01H8Y427AYC9SDK6SFSSEHH376" + - _WHAT! you don't remember me? how rude!_ + +% id = "01H8Y0CKD1NJPAH1SBNN5T9KQT" +- actually I really like Blueprint + + % id = "01H8Y0CKD1YPXAR8KH3JPCD3HW" + + lots of visual languages generally feel really unpleasant to write (looking at you Scratch), but somehow Blueprint feels like exactly the opposite + + % id = "01H8Y427AYWPYJHGGS63B7C8SN" + - (it's possible Scratch got better since I last used it like 5 years ago but I remember it being pretty cumbersome to use. + I had no reason to revisit it since so I simply don't know if it's any better now, but if it is, [let's chat][branch:hello]!) + +% id = "01H8Y0CKD1G06CG62XWZ02JREC" ++ writing Blueprints is actually pretty darn nice and there's a lot to learn from the editor UX and basic refactoring tools + + % id = "01H8Y0CKD1G86TY8AF6Z2SQ85P" + + when you drag your mouse out of a pin, and a window will pop up giving you suggestions on what could be connected there + + % id = "01H8Y0CKD1P9SNK3TV967M705C" + + then you select from the list and it creates the node, autoconnecting stuff as necessary + + % id = "01H8Y0CKD1PQS2J2WB22ASZY17" + - one of the nicer autoconnections it can do is when you want to call a function on an actor component + + % id = "01H8Y0CKD16PFNWJ6EAARHA7BD" + - instance functions require you to pass in a `self` to call the function on + + % id = "01H8Y0CKD1FVPCA5NBY5KK1F5X" + - so what it does is it suggests functions to call on all the _concrete components + you already have in your actor_, and when you select something like `Destroy Component (DefaultSceneRoot)`, + it'll not only create a function call node, but also hook up `DefaultSceneRoot` as its `self` parameter + + % id = "01H8Y0CKD1KM42PKVSGB4QASG3" + + when you try to connect two pins of incompatible types, it'll automatically insert a conversion node for you + + % id = "01H8Y0CKD1NES5RBGVTPRH3F0Q" + - Blueprint is strongly typed so you can't just pass in a `Float` where a `String` is expected, but luckily this makes the system way less painful + + % id = "01H8Y0CKD10GQBNNP0RBJEWKW4" + - I do have a gripe with this though and it's where it places the node. it tries very hard to center it but unfortunately never succeeds. + + % id = "01H987QXFE445XNN5YDS2FYR5F" + + perhaps a bug I could fix one day? + + % id = "01H987QXFEYSE260S996BE84DV" + - from [Oskar Kogut](https://github.com/kretoskar): if you change a `BlueprintCallable` function to `const` (or otherwise make it pure,) the editor will automatically correct the `Exec` pin flow for you + +% id = "01H8Y0CKD1C5TJXXD40B99WQ3C" ++ the design of Blueprint the Language is pretty dated - it is still an imperative language and has a concept similar to statements (`Exec` pins), which breaks the entire idea of pure data +flow and introduces control flow into the mix + + % id = "01H8Y0CKD1J2P2HZ507YBSNVKK" + - this split is called _pure_ and _impure_ nodes, where impure nodes are those that perform control flow (ie. those with `Exec` pins) + + % id = "01H8Y0CKD1P5JQCGHEY405KKPH" + + this results in weird edge cases like needing two separate node types to handle branching (one that can have side effects - `Branch`, and another that can't - `Select`) + + % id = "01H8Y0CKD1EGWTQYHT2WYQSZY5" + - `Branch` is used to shuttle control flow between two `Exec` lines, based on a `Bool`. you get a `True` branch and a `False` branch + + % id = "01H8Y0CKD1WFEWNYPZWGCH3N7X" + + and `Select` is used to choose a value based on another value, kind of like a ternary in C++ + + % id = "01H8Y0CKD156C0ZAXK7JS9W81D" + - however it is quite annoying because you can only switch on enums (and other stuff that has a finite set of values,) whereas with `Branch` you can use any `Bool` condition you want + + % id = "01H8Y0CKD1YP7Q3HVJJZNJAJKG" + + this would be fine if not for the existence of Gameplay Tags, which precisely _do not_ have a finite set of values + + % id = "01H8Y0CKD1P7D9QMPVQYWSDFT5" + - there is a `Switch on Gameplay Tag` node, but that is for control flow and not data flow! + + % id = "01H8Y0CKD126918N282MNBXD2C" + - this isn't an unsolvable problem but it illustrates the pure vs impure issue pretty well - you'd have to duplicate the implementation of `Switch on Gameplay Tag` to have + a version without an `Exec` pin + + % id = "01H8Y0CKD1N37WTCY66CM7R198" + + I'm seeing a bit of a semblance to the classic [function coloring problem][def:article/function_coloring] + + % id = "01H8Y0CKD19JMY87YY50M3RCQF" + + except where it usually applies to the `async` concept found in most modern programming languages, here it applies to the concept of control flow vs data flow + + % id = "01H8Y0CKD1Q8RXXK3KE4F4XAFF" + - and speaking of `async`, [Blueprint handles the classic `async` problem very gracefully][branch:01H8Y0CKD106HXQAJK87XV0H93]! + + % id = "01H8Y0CKD106HXQAJK87XV0H93" + + despite its flaws, one of Blueprint's strengths is asynchronous and latent tasks + + % id = "01H8Y427B03JNPTWW025ES176K" + - since control flow is based on those `Exec` pins, you can easily map your classic concept of callbacks to simply firing off the appropriate `Exec` pin + + % id = "01H8Y427B05AER1R4XK1GZ6A0M" + - for example the node for playing animations (`Play AnimMontage`) has a few pins coming out of it that signal playback events like `On Ended`, `On Blend Out`, `On Interrupted` + + % id = "01H8Y427B01SE52ZYA410QKWDQ" + - and you wouldn't even know these are implemented as delegates in C++landia. it just feels like a first-class feature + + % id = "01H8Y427B0V2Y76JJ3Z229PD15" + - the only gripe I have is that you can only have latent nodes in the main event graph (you cannot have them within functions) + + % id = "01H8Y427B0SPJ3NJCFS7S4YGR9" + - which is annoying but not terrible, since most of that latent, high level gameplay logic happens inside the main event graph anyways + +% id = "01H8Y96DGCWWTAP5X8ZYPCJZQC" ++ the editor UI, despite [being helpful as it is][branch:01H8Y0CKD1G06CG62XWZ02JREC], is far from perfect + + % id = "01H8Y96DGCRP0W6YWJ3PYJ2GES" + - it's actually quite janky and there tend to be brief flashes of content falling into place + + % id = "01H8Y96DGDVZ4DZ4AZE7EDYNFP" + - this is true of other parts of the Unreal editor UI but I'll focus on Blueprint here + + % id = "01H8Y96DGDDRA8DD6PRGDCF8GP" + + node UIs are laid out lazily, by default using an algorithm that does not produce precise results for pin locations + + % id = "01H8Y96DGDT0Y23G86HEKNWF4H" + - which means that when you first load a Blueprint, some of the wires will be bent in weird ways, and will fall into place as you zoom out and explore the graph more + + % id = "01H8Y96DGDCEF6FEQWGX2BQ6AH" + - the effect looks quite janky and really upsets my inner perfectionist + + % id = "01H8Y96DGDJG41P3XTFE8F4Y1M" + + as you zoom out, the nodes start looking just a little bit different due to font sizes being snapped to integers + + % id = "01H8Y96DGDRCBKWBXC7AXZV43E" + - at very low zoom levels, nodes stop rendering their text altogether, which makes their layout shift even more. + + % id = "01H8Y96DGDGRBZXWH31G08FRYM" + - the effect of this is that nodes themselves take up less space, and it appears as though there is more space between them than there actually is + + % id = "01H8Y96DGD1QSAJ0QWD2ZYXKEW" + - which can make it frustrating to lay nodes out on a large scale, because you'll only find out your nodes are overlapping when you zoom in real close + + % id = "01H8Y96DGDSM03EJJVN9FS6SSB" + - there's a `Straighten Connection` feature, which you can use to make your graphs look more aesthetically pleasing, but it only straightens the nodes such that they look good on the current zoom level + + % id = "01H8Y96DGDNTKMGSJZDJN2GSJB" + - so what'll happen with it sometimes is you'll straighten a connection, then zoom in, and the connection won't be quite straight because of the aforementioned layout shift + +% id = "01H8Y0CKD1103FHF332M2Q4MG7" ++ maintaining Blueprints in a large project could be a lot better + + % id = "01H8Y0CKD1PPEPX8EEFRAM2VE1" + + with regards to your graphs becoming really large + + % id = "01H8Y0CKD1DFSJ4BDPPFMGK66M" + - everybody kinda sorta just formats nodes however they see fit, and there is no unified autoformatter + + % id = "01H8Y0CKD1VRVNMZ827RF7XBCA" + - there's a reason people say Go's tooling is frickin' amazing, you know. it keeps codebases consistent! + + % id = "01H8Y0CKD1980VGHFBYGM8PN3E" + + this results in what we Hat in Time modders used to call _Kismetti_ in the Unreal Engine 3 days but nowadays we'd call _Blueprintti_ + + % id = "01H8Y0CKD179SBZ58F5JMDC5F3" + + which is a portmanteau of Blueprint and spaghetti. + + % id = "01H8Y427B0PJN75GA33S9CZJYH" + - I can't believe I remembered the spelling of that word. *portmanteau*. + + % id = "01H8YT7R15B3Z3T486DB53TR51" + - there are plugins on the marketplace that solve this, but I refuse to believe Epic Games doesn't have this problem themselves + + % id = "01H8YT7R15VTF7VPX5QK7K233J" + - I'd guess it's just not very high up their priorities + + % id = "01HA4HJKRVQ9GVMNY6NSY0T3T6" + - refactoring your nodes is a hell of a pain. Blueprint is kind of write-only + + % id = "01HA4HJKRVBSRB5T1GM0TBE1C7" + - say you're calling `ApplyGameplayEffectToTarget` a bunch of times and you want to replace those occurrences with a custom function that wraps `ApplyGameplayEffectToTarget` + with some extra semantic information, to make it more discoverable, searchable, and easy to use + + % id = "01HA4HJKRVGD7CW6T3MHRKNJS7" + - well then good luck :hueh: + + % id = "01HA4HJKRVBN3RR32Q9WHMKVFY" + - in a text-based language you could use a dumb search and replace to accomplish this task, but there is no such thing in Blueprint. :cry: + + % id = "01H8Y0CKD1QF5YBTKF3JEZCN5W" + + with regards to assets (how long this darn stuff takes to load) + + % id = "01H8Y0CKD1B1MZH39Z7EKB6KDT" + - the biggest offender here being that hard references are the default + + % id = "01H8Y427B17K7219TPH8VRFZ96" + - thus you can add a Mesh Component to your Blueprint and it'll load *the entire mesh with all the textures and skeleton and everything* when you wanna tweak a variable or some logic in the event graph + + % id = "01H8Y427B1QNZHJ5Z8W0QNFYPE" + - and not asynchronously in the background, you will have to _wait_ for it to finish loading. which is pretty annoying + +% id = "01H8Y0CKD16HEQKQX1NJG9GG42" ++ the runtime performance isn't the best for a few reasons + + % id = "01H8Y427B1ZKJA16V17NG80QHS" + - the VM isn't implemented in the most optimal way + + % id = "01H8Y427B1JJD3EK24DCG76GR0" + - I've analyzed this in my [`dispatchers` repository][def:dispatchers/repo] if you wanna have a read + + % id = "01H8Y427B1T148Y0T8E48DKJ3N" + - and that hard reference thing can make gameplay stutter when you're loading in new assets, but that's a more widespread issue than just with Blueprints + + % id = "01H8Y427B15BD0HJWM2Y3EZBSZ" + - but in reality most of the logic you're implementing in Blueprints (high-level gameplay stuff) shouldn't be that performance sensitive + + % id = "01H8Y427B1G7ZYE3S8RRHG5WRQ" + - and it's not hard to extract the performance sensitive parts to C++ because Blueprint offers tools for refactoring your code + +% id = "01H8YT7R15MFW3RRQAF8CM4EP6" +- but all that doesn't prevent me from liking it! + + % id = "01H8YT7R15ZJWBY0TN6F6HN95Y" + - since it's way more pleasant to write game logic in than C++, given that you don't need to wait a minute for your code to recompile. diff --git a/content/programming/unreal-engine/fixes.tree b/content/programming/unreal-engine/fixes.tree new file mode 100644 index 0000000..99dbb87 --- /dev/null +++ b/content/programming/unreal-engine/fixes.tree @@ -0,0 +1,120 @@ +%% title = "data validation quick fixes in Unreal Engine 5.4" + +% id = "01HP1FESY3H9K1QVSM1XMNC8NS" +- a few days ago I got a really cool change into Unreal, which allows you to add quick fixes to any data validation warning/error you emit: + +![a screenshot with a validation error in it; beneath the error there's a hint that it may be fixed automatically, coupled with a link you can click on to fix the issue][pic:01HP1G5WC29GP4KQY1NV1F1RR1] + +% id = "01HP1FESY3K11EJJ9NSFBDCTWS" ++ you can get this change in... + + % id = "01HP1FESY3CP8AJ00AQ9B6FQB2" + - [Git commit `0a6de35a5beb8534e19579cf1058460b4eb2bc79`](https://github.com/EpicGames/UnrealEngine/commit/0a6de35a5beb8534e19579cf1058460b4eb2bc79) + + % id = "01HP1FESY3RW98YQZFS04Q7E7C" + - Perforce changelist 31126352 + +% id = "01HP1FESY3XJRMHKB173XWF130" ++ the API revolves around the `UE::DataValidation::IFixer` type. _fixers_ are pieces of code that can fix your issues given their application conditions are met + + % id = "01HP1FESY38JWXNSJKPZNHP33Q" + + the interface you have to implement is: + ```cpp + struct IFixer + { + virtual EFixApplicability GetApplicability(int32 FixIndex) const = 0; + virtual FFixResult ApplyFix(int32 FixIndex) = 0; + } + ``` + + % id = "01HP1FESY3PZH00WDD85CNF1BX" + - for the curious cats among us: `FixIndex` is an arbitrary number that can be passed to `FFixToken`, to handle multiple different fixes with one fixer + + % id = "01HP1FESY3328D7ECZZX3EZCNE" + + first, the editor calls `GetApplicability` to know whether the fix can be applied + + % id = "01HP1FESY32EFSRX75ZWJ0K7PW" + - `EFixApplicability::CanBeApplied` should be returned if the fix can be applied at the moment + + % id = "01HP1FESY3RN3ECQHJ8R3HS4GD" + - `EFixApplicability::Applied` should be returned if the fix has been applied and can no longer be applied anymore + + % id = "01HP1FESY327FZMRZ64844XC9A" + - `EFixApplicability::DidNotApply` should be returned if the fix was not applied and can no longer be applied anymore + + % id = "01HP1FESY3N19T00CNY2T182VG" + + then, if `GetApplicability()` returns `EFixApplicability::CanBeApplied`, `ApplyFix` is called to actually run the fix + + % id = "01HP1FESY3NGQRKA57QTTVC19W" + - this function is safe to assume the caller has ensured that the fix `CanBeApplied` and therefore need not do any extra validity checks + + % id = "01HP1FESY3AAEHF4HSMAJ3B21H" + - other than that it's free to do whatever it wants + + % id = "01HP1FESY3CBMBJA3CQPEMCFND" + - after a fix is applied, the fixer returns an `FFixResult` which is used to display a notification to the user informing them of the changes + + % id = "01HP1FESY3GB4N76JDV8RVG4VD" + - fortunately you don't have to define a new struct for each fix, and instead can use `UE::DataValidation::TLambdaFixer` together with the `UE::DataValidation::MakeFix` function for more convenience + +% id = "01HP1FESY3EJ7TK4SPTD0TBBN9" ++ once you have a fixer, you can display it in your (`FTokenizedMessage`-based) validation messages using `FFixToken` + + % id = "01HP1FESY30HDA6JNR323GXD3D" + - minimal example: + ```cpp + auto Message = FTokenizedMessage::Create( + EMessageVerbosity::Error, + LOCTEXT( + "FoundNoneEntries", + "Found None entries in ability array." + "Please remove them, otherwise they may cause crashes during runtime." + ) + ); + Message->AddToken( + UE::DataValidation::MakeFix( + [this] + { + Abilities.SetNum(Algo::RemoveIf( + Abilities, + [](const UGameplayAbility* Ability) { return Ability == nullptr; } + )); + return FFixResult::Success(LOCTEXT("NoneEntriesRemoved", "None entries have been removed")); + } + ) + ->CreateToken(LOCTEXT("RemoveNoneEntries", "Remove the None entries")) + ); + Context.AddMessage(MoveTemp(Message)); + ``` + +% id = "01HP1FESY3V73R3JZEQHQ36V58" +- the user can then apply a fix by clicking on it in the Message Log message that contains it + +% id = "01HP1FESY3JM8WPZMRNCZC8GBA" ++ fixers can be freely stacked and composed - there are a few such layers available out of the box in the engine + + % id = "01HP1FESY3VK9X1TB81VR2VA83" + - the set is quite limited at the moment, but you're free to create your own or contribute them to mainline Unreal :ralsei_love: + + % id = "01HP1FESY3TC6DMBWQ3CEMGRW1" + - `UE::DataValidation::FSingleUseFixer` makes it so that your fix's applicability becomes `EFixApplicability::Applied` after the user applies the fix + + % id = "01HP1FESY32ZA4K57ATCKPM800" + - `UE::DataValidation::FObjectSetDependentFixer` makes it so that your fix becomes `DidNotApply` after the specified objects are deleted from memory + + % id = "01HP1FESY3W381HMBCEGCZ3HK7" + - `UE::DataValidation::FAutoSavingFixer` tells the user to save any assets modified by the fix after it's applied + + % id = "01HP1FESY3SENV59V4462YSZJY" + - `UE::DataValidation::FValidatingFixer` runs data validation on any assets modified by the fix after it's applied + + % id = "01HP1FESY3AZN3AVF7Z02JHXZA" + - `UE::DataValidation::FMutuallyExclusiveFixSet` is actually not a fixer, but a fixer _builder_ - + you give it a set of fixers, and it will make it so that when one is applied, it becomes `EFixApplicability::Applied`, and the rest becomes `EFixApplicability::DidNotApply` - + thus creating a set of mutually-exclusive fixes + + % id = "01HP1FESY3CC1NZZMQQP56TTD4" + - you can refer to the `DataValidationFixers.h` header file for more documentation + +% id = "01HP1FESY3WH21KDDYAHWZG294" +- all of this is going to be available in Unreal 5.4 :sparkles: diff --git a/static/pic/01HP1G5WC29GP4KQY1NV1F1RR1-data-validation-quick-fixes.png b/static/pic/01HP1G5WC29GP4KQY1NV1F1RR1-data-validation-quick-fixes.png new file mode 100644 index 0000000..f7aa285 Binary files /dev/null and b/static/pic/01HP1G5WC29GP4KQY1NV1F1RR1-data-validation-quick-fixes.png differ