Will the memory of ParticleSystem be affected by maxparticles

1）ParticleSystem Your memory will be affected MaxParticles Influence
​2） Use the code to modify the image compression format and report an error
3）Unity Texture import settings have an impact on memory
4）Unity Solution for video playback in

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This is the first 285 piece UWA Push of technical knowledge sharing . Today we continue to select and develop a number of 、 Optimization related issues , Suggested reading time 10 minute , If you read it carefully, you will get something .

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Memory

Q：ParticleSystem Your memory will be affected MaxParticles Does the value set affect ?

A： Did a test on the real machine ,Unity 2020.3.17, millet 9. The special effect of the test is Unity default ParticleSystem Special effects , give the result as follows ：

As you can see from the picture above , Memory is affected by “ The actual maximum number of particles ” Influence ,（ It can be roughly understood as duration * Number of launches per second , Don't consider Burst How to launch ）. When the number of launches is 0 when ,ParticleSystem There is a 9416Byte Memory footprint , This is Unity Occupation of built-in serialized things .

in addition , When “ The actual maximum number of particles ” after ,Active The number of particles increases with playing time , Memory usage will not change , As shown in the figure below .

 

PS：
When ParticleSystem What was launched was Mesh when , Can cause Gfx Memory up , And this Mesh Memory usage is not counted Assets/Mesh In memory usage .

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Texture

Q： When you want to add a picture , Automatic processing of picture settings , As a result, the setting of the picture times is wrong , There is no solution on the Internet , Error is as follows ：Selected texture format ‘Unsupported’ for platform ‘Android’ is not valid with the current texture type ‘Sprite’.

Unity edition ：2019.4.34f1

public class TextureImporterProcessor : AssetPostprocessor { void OnPostprocessTexture(Texture2D texture) { bool haveAlpha = textureImporter.DoesSourceTextureHaveAlpha(); textureImporter.isReadable = false; textureImporter.mipmapEnabled = false; textureImporter.alphaIsTransparency = haveAlpha; textureImporter.textureType = TextureImporterType.Sprite; textureImporter.textureCompression = TextureImporterCompression.Compressed; TextureImporterPlatformSettings androidSettings = new TextureImporterPlatformSettings() { name = "Android", overridden = true, format = haveAlpha ? TextureImporterFormat.ASTC_RGBA_6x6 : TextureImporterFormat.ASTC_RGB_6x6, }; textureImporter.SetPlatformTextureSettings(androidSettings); TextureImporterPlatformSettings iOSSetting = new TextureImporterPlatformSettings() { name = "iPhone", overridden = true, format = haveAlpha ? TextureImporterFormat.ASTC_RGBA_6x6 : TextureImporterFormat.ASTC_RGB_6x6, }; textureImporter.SetPlatformTextureSettings(iOSSetting); textureImporter.SaveAndReimport(); } } 

A1： It may be the problem of texture format , I'll put ASTC_RGBA_6x6 Change to ASTC_6x6 There is no such error report .

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A2： Add upstairs ,TextureImporterFormat There is a problem with the format specification ,ASTC Integrated with A The format of , So the code is unified into ASTC_x 了 . In the new 2020 There is no more in the version ASTC_RGBA And ASTC_RGB The distinction between , All unified into one interface ASTC_x In the , It should be the problem of version transition ,Unity 2019 There are many transition problems , stay 2020 It's much better up there .

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Texture

Q： a sheet 2048x2048 But the actual pixels are only 512x512, And a 512x512 What's the difference between your pictures ？ We're making a system like a paper doll , Want to set a standard . Currently scheduled 512x512 The size of the （ For scalability ）. But most dress up sizes may actually be only 250x250, Want to know if there is actually a difference between loading and memory ？

A1： Experimental data , The size of the same picture is 1024 Graph , The project settings are as follows , Compare the results ：

 

The above test data are in PC Test data under . Data on the phone , The landlord can test it by himself . In the early stage, we can consider using 512 Make the original drawing according to the size of , Then make a tool , Select the compression size you need when sending out the package .

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A2： Continue to answer upstairs .

After the texture is loaded into memory, the calculation formula of memory occupation is ：
Texture memory （ byte ） = wide x high x Pixel byte
Pixel byte = Number of pixel channels (R/G/B/A) x Channel size
in other words ： Runtime size = Long x wide x The size of each pixel

give an example ：RGBA 8888 It represents the channel RGBA Each channel occupies 8bit So one pixel takes up 4bytes. so , If the picture size is 1024x1024, Then size =1024x1024x4/1024/1024 = 4MB.

In the example upstairs ASTC 4x4 block Compressed format .

ASTC 4x4 block Compressed format , Each pixel occupies 1 byte ,8bits. a sheet 1024x1024 The compressed size of the map is 1MB.

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Video

Q： Need to play video in the game , Meet some basic needs , For example, play remote video , Broadcast as you go down , Set the video playback speed , Video progress bar , Pause or something .

Currently known, you can use your own Video Player、AVPro and Sofdec2 These three paragraphs , I'd like to ask if there is any big guy system that has studied video playback , Can share a little experience , Thank you for .

A： On the three video methods mentioned in the title , I used Video Player and AVPro.

In ordinary use Video Player Has been able to meet most of the needs , But in terms of video compatibility , And platform applicability ,AVPro than Video Player Much better , and Video Player You also need to encapsulate some interfaces to facilitate your use .

Video Player There are some specific required formats on each platform , Therefore, we should also control our own compatibility , And probably in Android On the platform , Some videos will cause some inexplicable black screens . Its advantage lies in its lightness , No need for too much Integration , Good compatibility with the engine , Upgrading the engine will not cause the trouble of inconsistent versions .

AVPro Some of the disadvantages of are more functions , For some unnecessary functions , Will be more bloated , It's not as compatible with the engine Video Player. The advantages are obvious , The function is still very powerful , And it has a good performance in the compatibility of the platform . There are some fixed decoding algorithms , stay Android The performance on the platform is the most obvious .

Many things are double-edged . Look at your needs , No best , Only the most suitable . If you have something, you must give it up , Give and take . You should be specific to your needs and the limitations of the current project , Think about what suits you .

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The cover image comes from ：GPU Particles Unity
be used for Unity Of GPU particle system .

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