These Weird Optimizations Made Our Game Run 10x FASTER! — Transcript

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1. 0:00So, what you're seeing on the screen
2. 0:01right now is roughly 1,400 bullets being
3. 0:05fired every second with the game running
4. 0:08at 60 frames per second. No stuttering
5. 0:10and no lag spikes. But how?
6. 0:14Hey guys. So, me and my team are making
7. 0:17a physics-based FPS game. And in this
8. 0:19video, I'm going to talk about all the
9. 0:21various tricks and methods we used to
10. 0:24take our game from running like a
11. 0:25PowerPoint presentation to a buttery
12. 0:27smooth performance. So our game is
13. 0:30simply chaotic. There is a lot of moving
14. 0:32objects, enemies left and right, and
15. 0:34explosions everywhere. So for our game
16. 0:37to handle all of this, optimization was
17. 0:40a number one priority. However, the one
18. 0:42thing we refuse to cut down on is
19. 0:45projectiles, and there is a lot of them.
20. 0:47In many games, like for example,
21. 0:49Counterstrike, Left 4 Dead, Team
22. 0:51Fortress 2, or GTA games all have quote
23. 0:54unquote real weapons. In real life, most
24. 0:57weapons fire so fast, you can't even see
25. 1:00the bullets being fired. Now, why is
26. 1:02this important? Well, because you cannot
27. 1:04see the bullet, developers often don't
28. 1:06bother simulating them to save
29. 1:08performance. In such games, the moment
30. 1:10you fire a weapon, you instantly hit a
31. 1:13target. This is often called hit scan
32. 1:15projectile, and in most cases, it works
33. 1:17great, but this only works if the
34. 1:19projectiles are completely invisible.
35. 1:22Our game is set in a sci-fi world and
36. 1:24when you have a weapon that's literally
37. 1:25called plasma gun, you kind of expect to
38. 1:28see something like this. So if our game
39. 1:30cannot use heat scan projectiles, how do
40. 1:32we deal with this? Well, one option is
41. 1:35to treat each projectile as a physical
42. 1:37object that is created each time you
43. 1:39fire a weapon. This is actually how our
44. 1:42game handled projectiles at first. And
45. 1:44honestly, it worked great. Or at least
46. 1:47it seemed like it. When I started
47. 1:48testing the game, it ran at like 15
48. 1:51frames per second. And all of this is
49. 1:53because of something called
50. 1:56basically our game is multiplayer and
51. 1:58every single one of those bullets had to
52. 2:01be sent over the network for other
53. 2:03players to see. But when there is
54. 2:05hundreds of bullets constantly being
55. 2:07sent, it completely tanks the
56. 2:08performance of the whole game. This is
57. 2:11thanks to something called network
58. 2:12bandwidth. To put it simply, network
59. 2:15bandwidth is kind of like a door into a
60. 2:17building. If someone wants to get into
61. 2:18the building, they must first go through
62. 2:20the door. But if there is too many
63. 2:22people trying to go through the same
64. 2:24door, it will create blockages. In our
65. 2:27game, bullets were like those people
66. 2:29trying to go through the door. The
67. 2:30problem is there was way too many of
68. 2:33them. So, how did we solve this issue?
69. 2:35How did we go from our game barely
70. 2:37clinging to life to being able to handle
71. 2:39thousands of projectiles with no
72. 2:41problems? Well, I live by the words,
73. 2:44fake it if you can't make it. All those
74. 2:46bullets you see, yeah, they're
75. 2:48completely fake. Now, before you start
76. 2:50saying how disappointed you are, trust
77. 2:51me, it's for the better. When you fire a
78. 2:53weapon, you can still see bullets being
79. 2:55fired. Only these bullets are purely
80. 2:58visual. They don't do anything. The real
81. 3:00magic happens on the server. The server
82. 3:02doesn't treat bullets like physical
83. 3:04objects. Instead, it simulates them. If
84. 3:07you think about it, all you need to know
85. 3:08is the starting position, direction, and
86. 3:11velocity of a bullet, and you can
87. 3:13accurately predict where a bullet will
88. 3:15be at a certain time. Basically, we've
89. 3:17reduced a whole object into just few
90. 3:20numbers. That's the reason why this
91. 3:22approach is lightning fast and causes
92. 3:25little to no performance heat.
93. 3:29Now, bullets were only one of the things
94. 3:32that needed to be optimized to run fast.
95. 3:34But there was a bigger issue. Grenades.
96. 3:37At first, the way grenades worked in our
97. 3:40game was pretty standard. You pick up a
98. 3:42grenade, you throw it, this creates a
99. 3:44physical object in the world with
100. 3:46momentum and velocity, and then they
101. 3:48explode. I never tried optimizing
102. 3:50grenades that much because I knew
103. 3:52there's never going to be a situation
104. 3:54where there are too many of them in the
105. 3:56world at the same time. Well, that all
106. 3:59changed when we added this enemy into
107. 4:01our game. This enemy is called
108. 4:03Striderbot. And one of his attacks is
109. 4:06throwing grenades. Except he doesn't
110. 4:08throw one. No, he throws four every
111. 4:11second. That's a lot. Even more when
112. 4:14there is like two or three of them at
113. 4:17the same time. So, what did we do? I
114. 4:20tried using the same logic we used for
115. 4:22projectiles to simulate their movement
116. 4:24using math. The problem is projectiles
117. 4:26are linear. Grenades are not. They can
118. 4:29bounce off floors, walls, or anything in
119. 4:32any direction, which makes them very
120. 4:34unpredictable. So, we needed something
121. 4:36more sophisticated. Fortunately, with a
122. 4:39quick Google search, I found that all I
123. 4:41need is this simple equation. To put it
124. 4:44simply, this allows us to get a position
125. 4:46of an object at any time, which is
126. 4:49exactly what I was looking for. Of
127. 4:51course, actually implementing this into
128. 4:53our game was a bit more difficult, and I
129. 4:56ran into a few problems. But eventually,
130. 4:58I got it working perfectly, and now we
131. 5:01can even have a whole fountain of
132. 5:03grenades with no performance issues. By
133. 5:06the way, this took a long time to make,
134. 5:07so please subscribe. Anyway, pretty much
135. 5:10everything works flawlessly now, except
136. 5:13one thing.
137. 5:18Since we started working on the game,
138. 5:20enemies had many problems, but one
139. 5:22problem was persistent turrets. Every
140. 5:25enemy in our game has them, and it's
141. 5:27what they use to attack players.
142. 5:29However, to target players, they need to
143. 5:31rotate to face them. And this simple act
144. 5:34of rotation is what caused huge
145. 5:37performance issues. They would often
146. 5:38take half of the available network
147. 5:41bandwidth, and I'm talking purely just
148. 5:43turrets.
149. 5:44At first, I tried rotating threats
150. 5:47through a script, but using C frames is
151. 5:49too expensive. I tried using animation
152. 5:51rigs, also too expensive. I tried using
153. 5:54a few mechanical constraints, too
154. 5:56expensive. I even tried using things
155. 5:58like a line orientation, but no. At this
156. 6:01point, I started to realize I was
157. 6:03running out of options. I was looking
158. 6:05for a solution that would allow me to
159. 6:07have many turrets with minimal
160. 6:08performance hit, but none seemed to
161. 6:11work. But then out of nowhere, I had a
162. 6:14light bulb moment. Instead of running
163. 6:16the turret logic on the server, why not
164. 6:19run the logic locally and have players
165. 6:21do the work and then the server would
166. 6:23just try to estimate where the touret is
167. 6:25looking. Even though this solution
168. 6:27wasn't ideal, it solved everything kind
169. 6:30of the performance hit was now minimal,
170. 6:32but if you remember, I said the word
171. 6:34estimate since the turret logic was in
172. 6:37the hands of the players. Now, the
173. 6:38server didn't have the most up-to-date
174. 6:41information, which means the server
175. 6:43could only guess where to fire a
176. 6:45projectile, and it wasn't synced with
177. 6:47the rotation. This sometimes resulted in
178. 6:49situations like this where you can see
179. 6:51the turret is facing a completely wrong
180. 6:54direction. This wasn't great, but
181. 6:56unfortunately, I didn't have another
182. 6:58option. So, this is how turrets worked
183. 7:01for a long time. But then, out of
184. 7:04nowhere, a perfect solution emerged.
185. 7:08In Roblox, there is something called IK
186. 7:10control. It's what allows you to easily
187. 7:12make procedural animations on your
188. 7:14characters. Our game uses this a lot.
189. 7:17But what I haven't noticed before is
190. 7:19that one of the modes on the IK control
191. 7:22is called look at, which rotates a part
192. 7:25to face a target. When I found this out,
193. 7:28I immediately started testing this. And
194. 7:30to my surprise, not only does it work
195. 7:33exactly how I want it, but it also
196. 7:35causes no performance issues. Like all
197. 7:38of this runs on the server, by the way.
198. 7:40All of this is real. Nothing is fake. If
199. 7:43I had known this earlier, this would
200. 7:45have saved me so much time. Well, I
201. 7:48mean, if there is anyone watching this
202. 7:50video that wants to make a lot of
203. 7:52tourets, I guess this is how you do it.
204. 7:54Now, just to clarify, there are more
205. 7:56optimizations we did, especially with
206. 7:59the enemies and how they work, but
207. 8:01that's for another video. Also, if you'd
208. 8:03like to know more about the game we're
209. 8:05working on, you can click this video
210. 8:07here. Trust me, you'll love it. Anyways,
211. 8:10that's all. Thanks for watching and see
212. 8:12you next time.