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Won't Fix



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Issue ID




URP 7.1+ build times have regressed, might be as high as 10x longer

Package: Scriptable Render Pipeline Universal


It seems build times have regressed between SRP 7.0.2 and 7.1.1

Note: checking can take a long time due to this slow build issue

Steps to repro:
- download and open project
- delete Library/ShaderCache
- select only first 30 scenes in build settings
- build project
- observe time taken is >30 mins
- change SRP 7.0.2 (not available in package manager? Get this from github)
- delete Library/ShaderCache
- build project
- observe time taken is <5 mins

Expected: similar or same time to build
Actual: much longer when using SRP 7.1.1

Reproduces: 2019.3.0b4 (no other versions checked because it is a package regression)

  1. Resolution Note:

    This is caused by FXC compiler taking longer based on the size of the uniform buffers. Since we increased light limits, the compilation time has increased. There's an workaround to trick FXC compiler that is to declare each uniform buffer as an array of 2 inside a cbuffer. However there's too much risk to take this approach given how much uncertainty there is and the amount of platforms. i.e, behavior could change in different version of the FXC compiler, or we can see different behavior on different platform. Based on this and the fact that we already have work in progress to optimize shader compilation time we decided we will not fix the cause of this regression.

Comments (1)

  1. nasos_333

    Oct 12, 2020 13:39


    I have an issue with URP project, i have multiple shaders and scripts and after a while the project started to go very slow when I do any changes to any shader, it takes around 1.5 minutes for each little change, making it impossible to work with fast iterations after my changes, is this something similar to this issue ?


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