Frame: Difference between revisions
(Rewrite intro: explain more of the process in creating a frame, make more clear that framerate is driven by the screen (let's ignore VRR...).) |
(→Framerate: Only Pikmin 3 runs at a fixed timestep. (Yes, Pikmin 1 has a dynamic timestep. I have no idea why it runs slower on PAL 50 Hz.)) |
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Other than that, the [[main menu]]s of the first two games, and the [[options menu]], [[high scores menu]], [[bonuses menu]], and [[area selection menu]] in ''Pikmin 2'' all run at twice the framerate of the normal game. | Other than that, the [[main menu]]s of the first two games, and the [[options menu]], [[high scores menu]], [[bonuses menu]], and [[area selection menu]] in ''Pikmin 2'' all run at twice the framerate of the normal game. | ||
Most modern games use the time it took to complete a frame as the timestep for the next frame, in order to keep the gameplay speed stable. | Most modern games use the time it took to complete a frame as the timestep for the next frame, in order to keep the gameplay speed stable. Only ''Pikmin 3'' doesn't dynamically adjust the timestep, which means that lag will also slow down the game. An example of this is the landing sequences in on the [[Wii U]]. | ||
{{todo|Why does Pikmin 1 at 50 Hz run slower, if it is capable of dynamically changing its timestep? (Source that it can: changing the vblank rate on Dolphin doesn't change the game speed.)}} | |||
==See also== | ==See also== | ||
Revision as of 19:17, September 5, 2024
Frames are a series of consecutive images that, when played in rapid succession, give the illusion of movement.
Most screens refresh at a regular interval, usually 60 times per second, and the period when they are ready to receive a frame from the console is known as vertical blanking interval (VBI). For a game to display its current state, it must perform the following steps for each VBI
- Get the player's input.
- With the CPU, update the world state. The simulation is discrete (e.g. the position of a moving object is changed once per update), with a timestep that is an estimate of the time it takes to finish the frame.
- With the GPU, render the updated world state to a frame. (Because the CPU and GPU are working simultaneously, there is one frame of latency.)
If the console has to process a large amount of instructions, it may fail to do render the frame before the VBI: this forces the console to resend the previous frame (assuming vertical sync is enabled), causing lag. More complex games may aim to render a new frame every n VBIs, at the expense of fluidity and responsiveness, but maintaining consistency.
If the timestep of the simulation is static, then a frame can be considered as the primary unit of time. In tool-assisted superplays, some tricks or glitches are "frame-perfect", meaning that there is a one-frame window in which an outcome can happen. This makes them difficult or impossible to perform consistently in real time.
Framerate
The mainline Pikmin games contain complex areas and several objects, most notably, the Pikmin themselves, with 100 of them being able to stay on-screen at once. Because of this, Pikmin, Pikmin 2, Pikmin 3 and Pikmin 4 target 30 frames per second, half of an ordinary screen's refresh rate (60 Hz).
The exception to this is the European version of Pikmin and Pikmin 2:, if the game runs at the PAL 50 Hz frequency, the framerate is lowered to 25 frames per second. Pikmin's physics timestep doesn't change, which causes the gameplay's speed to be slowed down by approximately 16.7% as a result, while on Pikmin 2 it is adjusted so that the gameplay speed remains the same. The GameCube version of the first game only supports PAL 50 Hz, while its New Play Control version and both versions of Pikmin 2 also support PAL 60 Hz.
Other than that, the main menus of the first two games, and the options menu, high scores menu, bonuses menu, and area selection menu in Pikmin 2 all run at twice the framerate of the normal game.
Most modern games use the time it took to complete a frame as the timestep for the next frame, in order to keep the gameplay speed stable. Only Pikmin 3 doesn't dynamically adjust the timestep, which means that lag will also slow down the game. An example of this is the landing sequences in on the Wii U.
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To do: Why does Pikmin 1 at 50 Hz run slower, if it is capable of dynamically changing its timestep? (Source that it can: changing the vblank rate on Dolphin doesn't change the game speed.) |