『部分工程文件点我下载』
『知乎转载链接』
『有点相关的Unreal Circle演讲』
Summary
因为本文涉及到的内容比较广，关于Niagara最基础的一些部分比如怎么新建、怎样添加使用模块就不详细说明了，没用过的同学可以先看一下Epic官方文档的介绍：
Niagara核心概念
和贾越同学的系列教学直播：
https://www.bilibili.com/video/av73602807
本次工程效果：
为了实现海浪拍到岩石上激起千层浪的感觉，我们可以看到有几个表现上的关键点
- 在岩石附近生成水花
- 水花激起的时机和位置与海水的流动匹配
- 出射速度受到海水运动和石头表面的撞击情况影响
- 激起后水花的体积感
海面的模拟 – Gerstner Waves
游戏里模拟海水的途径是一门艰深的课题，本文就不多涉及了。这里为了制作需要，介绍一下相对直观实用的Gerstner Waves。
在流体动力学中，Gerstner Waves是周期表面重力波的欧拉方程方程的精确解。它计算机图形技术之前很久就出现了，用来描述不可压缩流体的表面波动。
单一Gerstner Wave材质应用在一个平面上的效果如图：
数学时间
我们可以看到每一个点不止有Z轴方向的运动，也有XY轴的运动。并且这不是一个简单的sin波而是带有‘浪尖’的波形，这些都是Gerstner Wave的重要特征。
因为篇幅原因这里就不具体说公式了，本节末尾提供了我做好的材质节点可以直接下载取用。详细算法可以参考：
Chapter 1. Effective Water Simulation from Physical Models
https://developer.download.nvidia.com/books/HTML/gpugems/gpugems_ch01.html
简单说来，定义一个波形的属性有：
[高度, 前进方向, 波长, 陡峭度]
我们定义相位φ
φ = 方向 ⋅ 位置 / 波长 + 频率 * 时间
其中
频率 = sqrt(重力 * 2π / 波长)
那么以
z轴偏移 = 高度 * sin(φ)
xy轴偏移 = 陡峭度 * 高度 * 方向 * cos(φ)
的形式去移动海面的顶点，顶点会沿着椭圆绕圈（左图），一系列的顶点组合在一起就会形成具有浪尖的波形。
引擎内实现
在引擎里的实现可以用HLSL写在Custom节点里，你也可以选择用节点连。执行效率上，节点连出来的公式和HLSL代码没有区别。
材质函数 MF_GerstnerWave
核心部分：
float3 d = float3(sin(DirectionInDegrees * 0.0174533), cos(DirectionInDegrees * 0.0174533), 0); // 为了控制方便，输入并不是一个向量而是角度，这里转换一下
float w = 6.2831854 / L;
float theta = sqrt(6.2831854 * Gravity / L); // 由波长算出频率
float q = Stiffness / (Amplitude * w); // q是控制浪尖陡峭度的系数
float phase = dot((w * d).xy, WorldPosition.xy) – theta * Time; // 喂给cos和sin的相位
float3 offset = float3(q * Amplitude * d.xy * cos(phase), Amplitude * sin(phase)); // 照抄上面公式
这部分我放在了BlueprintUE.com里，点下面链接直接把节点复制粘贴到UE材质编辑器里就可以得到图上的节点：
https://blueprintue.com/blueprint/tt5p124n/
波形叠加
显然，一条波并不能说非常炫酷，Gerstner Wave的典型做法是把多条波叠加在一起。上面提到每条波可以控制的变量有：[高度, 前进方向, 波长, 陡峭度]
要合并多个波形，首先考虑的是波长，因为能组合的波长数量有限（8个已经很多了），我们无法完全参照真实世界的海洋数据，只能尽可能利用能付出的资源。由于波长相似的wave在叠加时看起来更有错综复杂的动态表现，我们可以在输入参数里首先给一个波长的中值LengthMedian，然后让不同wave的波长围绕这个中值变化。这样只要保留所有wave的波长与LenghMedian的比例，就可以通过改变LengthMedian来调整整个海洋的波浪大小：
在定义一组waves的结构FGerstnerWavesParameters中，美术可以在海洋的蓝图Actor上直接填写LengthMedian。
接下来，美术可以手动填写各个wave和LengthMedian的比例，也可以像我一样偷懒，填一个LengthMultiplierRange然后随机选取范围内的比例，在场景里拖动Seed直到随出一个好看的组合。
类似的方法同样适用于高度, 前进方向, 陡峭度。要注意的是，wave的高度和波长存在正相关关系，简单的做法是定义一个常数比例，让每个wave高度和和波长的比例保持一致。而在定义前进方向时会类似的给出一个DirectionRange定义前进方向的范围。
Niagara GPU粒子的生成
匹配水面位移
上面说了这么多，海面Shader内的位移数据其实并不能被外界直接读取，为了让Niagara能获取到海面的位移数据从而实现位置的同步，我们需要额外做一些工作：
方块：Niagara GPU particles
因为Gerstner Wave算法是确定性的，即给定同样的 [ 高度 | 前进方向 | 波长 | 陡峭度 ] 这样一组参数，不管在哪算出来的波形都是一样一样的。所以我们只要把与海面同样的参数传入Niagara System，就可以让Niagara粒子去‘追踪‘海面的粒子。（如上图）
传参
Normal难度：
上面说到，海面的波形是由好几个不同的Gerstner Wave组成，这里我用了8个，那么需要匹配海面的形状，其实在生成浪花时我们不用考虑所有8个waves，只考虑最大的一或两级wave，视觉上就很难看出不完全吻合的细节差别了。
Hard难度:
这一块可选阅读，可以跳过，对下面内容的理解没有影响。
可是如果我觉得这样做身体不适，非想传所有数据达到完美同步呢？ 也不是没有办法。4个参数 x 8组 = 一共32个float变量，手动命名并且在蓝图里拉面条，再在Niagara模块上一个一个拖上去也不是不行.. 如果你想做得灵巧些，我发掘了一个输入数组的hack：
因为Niagara还在beta阶段，一些功能还在持续改进中，这个hack可能以后也不需要。我介绍一下的另一个原因是觉得对增加对Niagara的理解有所帮助。
开始我想把数据通过DrawToRenderTarget写到一张贴图上，让Niagara读，但因为操作太不友好并且不支持CPU粒子放弃了。后来发现Niagara里的Curve型变量是同时支持CPU和GPU的，读取也很方便。我在蓝图里把需要的变量写入到一个Curve asset里，Niagara内reimport更新就可以，很方便。
不过Curve key的格式是有讲究的，Niagara CPU sim在读curve时，直接就读对应位置的key value。但GPU sim上会首先把curve编码成一个1×128像素的Lookup table，然后再读对应位置的数据，这就导致如果key的time位置不是100%对到LUT的像素位置上，encode后会出现偏差，这个偏差在我们现在的应用中是无法容许的。
好在encode的逻辑非常直接，只是取第一个key和最后一个key的time看范围，normalize到[0.0, 1.0]之间：
所以要达到key和LUT的像素对齐，最简单的方式是让time = [0, 1, 2… 127]，这样不需要额外操作，在GPU sim上读取即可。
最后一个key的time是127.0
这样我们就实现了可以在一个curve里记录128个float值。剩下要做的就是再BP里根据一定规则把8个wave的一系列参数编码，再从Niagara模块里通过相同规则解码。这里4个参数*8个wave，规则就是很简单的按照一定间隔记录了32个值。
按照一定间隔，在整数Time上记录了每一组parameters
在Niagara module中通过类似方式解压
定义GPU粒子的碰撞行为
Distance Field Collision
系统提供的collision模块非常健全，包括CPU trace碰撞，GPU depth / distance field碰撞等分支可以在下拉菜单中选择使用。我们这里使用GPU distance field碰撞，depth碰撞比较适合比较粗犷的效果，比如下雨下雪，稍微有点问题也看不出来，但如果水浪使用depth碰撞，岩石背面屏幕看不到的地方就会出错。
我们想有一些比较细腻的控制逻辑，比如这里水花撞到石头上，如果用默认的collision碰撞，反弹是朝着下图绿色的反射向量方向飞出去的，而流体撞到刚体的行为并不是这样完美的反弹，我们更想让它偏向下图紫色的角度。
下面三个gif分别展示不同反射角度的视觉：
定义这样的碰撞行为需要自己写模块，幸运的是这种逻辑都可以用Niagara的节点实现。引擎提供的Collision模块本身是一个宝藏，里面有各种碰撞的实现方式和模块编辑的best practice。在Collision – CollisionQueryAndResponse模块中我们探索一下可以发现：
点进去最底层的模块是：
即给出world position获得global distance field的数值和gradient，和材质里的DistanceToNearestSurface / DistanceFieldGradient结果是一样的，都是GPU内的query。
知道了这些，我们就可以很方便的自己写一个简单的collision判断：
并且在后面接上上面说到的反射角和切线角的逻辑–如果发现水浪粒子进行了第一次和岩石碰撞，那么就沿着我们想要的角度给一个初速度：
距离优化
同时因为有了distance field信息，可以在particle spawn时判断水浪粒子是否在岩石附近，如果不在就直接删除。
Smear
水花的材质想做好也是一项涉及很广的任务，我这里就是用了一个比较简单的云的贴图，稍微加工了下。值得一提的是通过particle的速度可以在材质里实现速度拉伸效果，对表达浪花飞溅的夸张形态非常有帮助：
实现方式也很简单，因为粒子sprite是朝向camera的，我们只要以local position和移动速度的点积缩放sprite即可：
Looking at this from the perspective of someone tired of generic content the contrast is striking, and a look at globalbuyingmarket maintained that distinctive feel, sites with strong editorial identity stand out against the bland background of algorithmic content and this one has clearly developed an identity worth recognising through careful attention.
Reading this on a difficult day was a small bright spot, and a stop at trusteddealstore extended that brightness, content that improves a hard day is content that has earned a particular kind of place in my reading habits and this site is occupying that uplifting role for me today which I appreciate clearly.
Anvelope 255/35/ R19
Anvelope Roadx
https://evacuator-rapid.md/ru/gindeshty
Honestly enjoyed every minute spent here, that is not something I say lightly, and a look at everydaydealshop confirmed I will be back, the bar for spending time online is high for me these days but this site clears it without effort which is high praise indeed from this reader who is usually rather demanding.
https://evacuator-rapid.md/soldanesti
1win пополнение через терминал 1win41943.icu
условия бонуса мелбет https://www.melbet19011.online
https://evacuator-rapid.md/dubasari
mostbet webes verzió http://www.mostbet30598.online
mostbet magyar nyelv beállítás http://mostbet30598.online
mostbet crash bónusz mostbet crash bónusz
мостбет бонус код https://mostbet07915.online
мостбет регистрация мостбет регистрация
mostbet акции http://www.mostbet07915.online
Appreciated how the writer anticipated the questions a reader might have along the way, and a stop at nextgenshoppinghub continued that thoughtful approach, you can tell when content has been edited with the reader in mind versus just published as a first draft and this is clearly the former approach across what I read.
Worth saying that the writing carries a particular kind of authority without making any explicit claims to it, and a stop at valuebuyingpoint extended that earned authority feeling, sites that demonstrate expertise through the quality of their explanations rather than by stating credentials are sites I trust most and this site has it.
1вин android http://1win41943.icu/
Reading this on a difficult day was a small bright spot, and a stop at trustedshoppingzone extended that brightness, content that improves a hard day is content that has earned a particular kind of place in my reading habits and this site is occupying that uplifting role for me today which I appreciate clearly.
A clean piece that knew exactly what it wanted to say and said it, and a look at clickfornewperspectives maintained the same clarity of intention, knowing the goal of a piece before writing is something most blog content lacks and the clarity of purpose here shows up in every paragraph for any careful reader to notice.
Reading this gave me something to think about for the rest of the afternoon, and after stockmrtktlite I had even more to mull over, the kind of post that lingers in the background of your day rather than evaporating immediately is genuinely valuable in an attention economy that punishes depth rather than rewarding it.
888starz apk تطبيق المراهنات 888
Reading this prompted me to dig out an old reference book related to the topic, and a stop at longtermbusinesspartnerships extended that connection to other sources, content that connects me back to my own existing knowledge rather than asking me to forget it is content with continuity and this site has that continuous quality.
Adding this site to my regular reading list, the post earned that on its own, and a quick stop at easypurchasecenter sealed the decision, the kind of place worth checking back with from time to time because it consistently produces material that holds up against a critical reading too which I really value.
Overview: the true casino brand known as true fortune is a modern gaming site that has quickly built a reputation across the UK. Operating from its flagship platform at true-fortune.com, the brand markets itself as a full-service destination for slots, tables and live gaming. You may also see it referred to as truefortune or simply true-fortune casino, the overall package caters to anyone wanting a sleek, trustworthy GB-oriented platform.
When it comes to game catalogue, the site serves up a genuinely huge line-up — think 3,000 to 5,000+ games. Leading providers like Pragmatic Play, NetEnt and Play’n GO supply the selection, which means generous return-to-player rates, progressive jackpots plus classic favourites. Jackpot pools frequently stretch to life-changing sums, which keeps things interesting.
The live casino is a genuine strength. Driven by Evolution and Pragmatic Play Live, UK members can take a seat at live roulette, blackjack and baccarat around the clock. Real dealers deal in real time from purpose-built studios, plus engaging entertainment titles such as Monopoly Live round out the offering. It’s as immersive as online play gets.
Bonuses and offers, the site keeps things generous. Fresh sign-ups can claim a welcome package worth ?1,000 plus 100 free spins, while regulars enjoy a free spins deal for those testing the waters. Reload deals, weekly cashback and a tiered VIP scheme add ongoing value, remember to reading the playthrough terms first. UK readers can check the latest offers on true fortune casino uk for the freshest deals.
On practicalities, the site handles plenty of payment methods — Visa, Mastercard and Skrill, Skrill and Neteller, plus crypto options like Bitcoin. Registration takes refreshingly fast, with a low first deposit near ?20, while cashouts land quickly.
In summary, true fortune casino is supported by 24/7 customer support, a smooth mobile app for iOS and Android, and solid licensing and security. For UK players looking for a trustworthy, feature-rich home, this one is a strong contender.
mostbet egyenleg ellenőrzés http://mostbet30598.online
Over the course of reading several posts here a pattern of quality has emerged, and a stop at everydaybuyinghub confirmed the pattern, the difference between sites that hit quality occasionally and sites that hit it consistently is huge and this site has clearly demonstrated the consistent kind through what I have read this morning.
888starz apk تطبيق المراهنات 888
Bookmark earned and the bookmark feels like a permanent addition rather than a maybe, and a look at trusteddealmarketplace confirmed that permanent status, the difference between durable bookmarks and ephemeral ones is something I have learned to feel quickly and this site triggered the durable feeling almost immediately during my first read here.
mostbet слоты фриспины mostbet07915.online
Now feeling the quiet pleasure of finding writing that takes itself seriously without being self serious, and a stop at globaltrustpartnerships extended that subtle pleasure, the gap between earnest and pretentious is fine and this site has clearly chosen to land on the earnest side without slipping over into pretentious which is impressive.
Just want to flag that this was useful and not bury the appreciation in caveats, and a look at discovergrowthframeworks earned the same direct praise, recognising good work without hedging it with criticism is something I try to practice because over qualified compliments tend to read as backhanded and miss the point sometimes.
Working through this site has been a small antidote to the shallow content that fills most of my reading time, and a stop at quiettidegoods extended that antidote function, sites that quietly improve the average quality of my reading by being themselves are sites worth supporting through return visits and recommendations consistently.
If I had to defend the time I spend reading independent blogs this site would feature in the defence, and a look at simpleecommercesolutions reinforced that defensive utility, the ongoing case for non algorithmic reading is one I make to myself periodically and sites like this one provide the actual evidence that supports the case clearly.
Just sat with this for a bit longer than I usually would because the points are worth thinking about, and after strategictrustsolutions I had even more to chew on, the kind of post that nudges your thinking forward without forcing the issue is something I have always appreciated in good writing online.
Now adding this to a list of sites I want to see flourish, and a stop at learnbusinessskillsonline reinforced that wish, the few sites I actively root for are sites that produce the kind of work I want more of in the world and this one has joined that small list based on what I have read so far.
تحميل تطبيق 888starz استار 888
Overview: true fortune casino stands out as an increasingly popular iGaming destination that has quickly gained a following among UK players. Anchored by its main hub at true-fortune.com, the operator aims to be a full-service home for real-money play. Some players know it as truefortune or even true-fortune casino, the experience is geared toward anyone wanting a polished and safe GB-oriented platform.
When it comes to game catalogue, the site delivers an impressively deep line-up — think 4,000+ slots and tables. Leading providers including NetEnt, Microgaming and Yggdrasil supply the catalogue, which means high-RTP slots, progressive jackpots and old-school fruit machines. Jackpot pools often stretch to life-changing sums, which keeps the sessions exciting.
Live dealer play is a real strength. Powered by industry leaders like Evolution, UK members can sit down at live roulette, blackjack and baccarat at any hour. Human croupiers stream in HD from purpose-built studios, and popular game shows like Crazy Time and Lightning Roulette complete the lobby. It’s about as authentic as a screen allows.
Bonuses and offers, true fortune casino keeps things generous. New players are welcomed by a sign up bonus up to ?500 and 200 free spins, and there’s often a free chip offer for new accounts. Cashback, reload offers and a tiered VIP scheme keep existing players busy, so it’s smart to reviewing the rollover conditions before you claim. You can find out more over at true fortune no deposit bonus 2026 for the freshest deals.
When it’s time to bank, the cashier handles a broad mix of payment methods — Visa, Mastercard and Skrill, e-wallets like Neteller, and even Bitcoin. Sign-up is just a couple of minutes, starting from a small entry point around ?10, while cashouts land quickly.
In summary, true fortune casino rounds things off with always-on assistance, a smooth browser and app platform, and solid regulation and SSL encryption. For British punters who want a reliable, well-stocked site, this one is a strong contender.
Now planning to come back when I have the right kind of attention to read carefully, and a stop at builddigitalgrowthpaths reinforced that plan, choosing the right moment to read certain content is a quiet form of respect for the work and this site is generating those careful planning behaviours from me consistently as a reader.
Thanks for the moderate length, neither so short it skips substance nor so long it bloats, and a stop at trustedshoppingnetwork hit the same balance, the right length is one of the hardest things to calibrate in blog writing and I appreciate when a team has clearly thought about it rather than defaulting.
Now saved this in a way that I will actually find again rather than the casual bookmark approach, and a stop at longtermvaluealliances earned the same careful saving, organising my reading bookmarks so that high quality sources rise to the top is something I should do more of and this site triggered that organisation today.
Decided I would read the archives over the weekend, and a stop at discovergrowthroadmaps confirmed that the archives would be worth the time, very few sites have archives I would actively read through but this one has earned that level of interest based on the consistent quality across what I have sampled so far.
At a glance: the true casino brand known as true fortune is a well-rounded gaming site that has steadily won over players among UK players. Built around its flagship platform at true-fortune.com, the brand aims to be a full-service home for real-money play. Some players know it as truefortune or even true-fortune casino, the overall package caters to players seeking a clean, reliable British-facing experience.
In terms of the game collection, this operator delivers a seriously large range — expect 3,000 to 5,000+ slots and tables. Big-name studios like Pragmatic Play, NetEnt and Play’n GO power the reels, delivering strong RTP percentages, progressive jackpots and blockbuster releases. Jackpot pools routinely climb into six figures, helping keep things interesting.
The live casino is a genuine draw here. Driven by Evolution and Pragmatic Play Live, you can join live roulette, blackjack and baccarat 24/7. Human croupiers stream in HD live on camera, with fun entertainment titles like Crazy Time and Lightning Roulette round out the experience. The result is as immersive as a screen allows.
On the promotions front, true fortune casino is genuinely competitive. Fresh sign-ups are greeted with a matched bonus of ?1,500 across your first deposits, and there’s often a free spins deal to start with. Cashback, reload offers and a rewards ladder add ongoing value, though it’s always worth reviewing the rollover conditions first. You can see the current codes on true fortune $25 free spins no deposit usa whenever you like.
For deposits and cashouts, the cashier accepts a broad mix of payment methods — debit cards, e-wallets like Neteller, alongside cryptocurrency. Sign-up is just a couple of minutes, with a modest first deposit around ?10, and payouts are handled fast.
To wrap up, this operator rounds things off with round-the-clock help via live chat and email, a smooth browser and app platform, and proper player-safety measures. For UK players who want a trustworthy, feature-rich home, it’s firmly on the shortlist.
mostbet secțiunea promoții mostbet secțiunea promoții
Thanks for the moderate length, neither so short it skips substance nor so long it bloats, and a stop at clicktoscaleideas hit the same balance, the right length is one of the hardest things to calibrate in blog writing and I appreciate when a team has clearly thought about it rather than defaulting.
chicken road historial de retiros https://chicken-road14981.icu
First impressions: the true casino brand known as true fortune is an increasingly popular gaming site that has quickly built a reputation with British punters. Built around its official home at true-fortune.com, the operator aims to be a one-stop venue for real-money play. Whether you call it truefortune or simply true-fortune casino, the offering is geared toward those chasing a polished and safe UK-friendly experience.
When it comes to game catalogue, the site serves up a genuinely huge selection — somewhere in the region of over 5,000 games. Leading providers such as Pragmatic Play, Big Time Gaming and Betsoft supply the reels, so you get generous return-to-player rates, bonus-buy features alongside old-school fruit machines. Jackpot pools frequently stretch to the tens of thousands, helping keep the sessions exciting.
Live dealer play is a real draw here. Powered by industry leaders like Evolution, players can take a seat at authentic dealer tables at any hour. Human croupiers stream in HD live on camera, and popular game shows like Crazy Time and Lightning Roulette top off the offering. It’s about as authentic as a screen allows.
On the promotions front, true fortune casino is genuinely competitive. Fresh sign-ups are welcomed by a sign up bonus up to ?500 and 200 free spins, while regulars enjoy a free spins deal to start with. Loyalty perks and reloads and a tiered VIP scheme add ongoing value, remember to reviewing the playthrough terms before you claim. Players can check the latest offers at fortune casino whenever you like.
On practicalities, the site supports plenty of banking options — Visa, Mastercard and Skrill, Skrill and Neteller, and even Bitcoin. Sign-up is refreshingly fast, starting from a small first deposit around ?10, while cashouts are processed swiftly.
Overall, true fortune casino rounds things off with always-on customer support, a slick browser and app platform, and solid player-safety measures. For British punters after a trustworthy, feature-rich home, it’s a strong contender.
pin-up apuestas copa libertadores http://pinup71548.icu
Introduction: the true casino brand known as true fortune is a well-rounded gaming site that has rapidly built a reputation across the UK. Anchored by its flagship platform at true-fortune.com, the site positions itself as a one-stop venue for real-money play. Some players know it as truefortune or even true-fortune casino, the overall package is geared toward players seeking a clean, reliable GB-oriented environment.
On the game collection, the site serves up a seriously large line-up — somewhere in the region of 3,000 to 5,000+ titles. Leading providers including Pragmatic Play, Big Time Gaming and Betsoft sit behind the selection, which means high-RTP slots, bonus-buy features plus classic favourites. Jackpot pools routinely reach the tens of thousands, helping keep things interesting.
Live dealer play is a genuine draw here. Streamed via industry leaders like Evolution, UK members can take a seat at professionally hosted games around the clock. Human croupiers stream in HD from professional studios, plus engaging entertainment titles such as Monopoly Live complete the experience. The result is as immersive as it comes.
When it comes to bonuses, the site is genuinely competitive. First-timers can claim a matched bonus of ?1,500 across your first deposits, while regulars enjoy a free spins deal for new accounts. Reload deals, weekly cashback and a tiered VIP scheme reward loyalty, though it’s always worth checking the wagering requirements first. UK readers can find out more over at true fortune no deposit bonus codes 2026 for the freshest deals.
On practicalities, the cashier handles a broad mix of banking options — Visa, Mastercard and Skrill, Skrill and Neteller, alongside cryptocurrency. Getting started is refreshingly fast, starting from a small first deposit near ?20, and withdrawals are processed swiftly.
Overall, true fortune casino rounds things off with always-on assistance, a slick browser and app platform, and proper regulation and SSL encryption. For British punters after a modern, generous casino, this one is firmly on the shortlist.