What optimization really means

[Mira Yurizaki]

http://www.pcgamer.com/what-optimization-really-means-in-games/

 

It probably already says what some of you might suspect, but I'll throw in some snippets:

On Dying Light (as an example)

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There was an outcry about the 'terrible unoptimized PC port' when Dying Light would not perform up to (arbitrary) standards at maximum settings. As it turned out, the draw distance slider in the initial version of the game was already above console settings at its lowest position, and went incomparably higher. People were so agitated, in fact, that the developer felt like they had to reduce the range of the slider to 55% of its former maximum in an early patch.

 

Would the game have been perceived as much more 'optimized' if this trivial step would have been taken before release? I definitely think so. Would it actually have been ‘better optimized’? No, absolutely not. Dying Light is a great example of just how difficult it can be to judge optimization, and also of the concerns developers might be limited by when implementing game options.

On DirectX 12/Vulkan

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For QLOC, unless the engine of a game already fully supports these new APIs, the effort of implementing low-level API support from scratch is not justifiable "for a mild improvement in performance that might anyway turn out to be non-existent once the port is completed".

On optimization as a whole

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Given the general focus of online discussions and reviews, as well as this article so far, this is a point that should be reiterated: optimization is a topic that concerns more than just graphics, although they obviously make up a very significant chunk of the processing time a game spends each frame.

 

As the development team at QLOC put it: "For us, optimization is also a lot about improving poor decisions with the controls, the gameflow and UI, tweaking the save/load system, improving netcode, and even fixing old bugs from the original title." I can imagine that this point of view is one appreciated by many who had to fight with mouse acceleration, input lag or byzantine UI decisions in other ports—and I’ve reported on a fair share of those myself. 

 

 

[manikyath]

In broad software development "badly optimized" means the developer -for whatever reason- chose an inefficient implementation of a piece of code, making it take significantly more resources to run than would be ideal.

 

These reasons could be widespread, and are not all bad:

- the code only needs to run once (think a script to convert an old file to a new format)

- there is a lack of time (this is when devs cut corners because corporate wants it done yesterday)

- the dev is straight up lazy, with no other excuse (there's plenty of examples here)

[Mira Yurizaki]

But what if some piece of code that runs great on one platform runs horribly on another and you have to support both?

[BrightCandle]

For the most part optimisation in game terms is just reducing the quality of the graphics in various ways. Games for consoles usually cut corners in the following ways:

 

- Reduced resolution and upscales to HD.

- Cheaper ambient occlusion algorithms such as SSAO instead of HDAO.

- Cheaper AA such as FXAA instead of MSAA.

- Deferred rendering to get more lights but stops the hardware being able to do a bundle of things like MSAA.

- Rendering shadow maps at much reduced resolution

- Reduced quality light shafts and particle effect lighting

- Less tessellation impacting the model quality

 

and many many more. That is what optimisation mostly is for games, reducing the graphics quality.  Just occasionally a game actually does get "optimised" in the developer sense where they improve the algorithm but it otherwise produces the identical result but its not what it normally means. So when users are clamouring for a game to be optimised typically what they are asking for is worse graphics. Some games don't appear to produce sufficient FPS for their visual look but that is ignoring the quality at which the various effects are actually rendered, there is a lot of choice for tuning a lot of the post processing algorithms use for lighting/shadows/AO/texture filtering and such but its always objectively "worse".