Unreal Engine is configuring libcurl for HTTP 1.1

[csciguy8]

There are most likely speed advantages from using HTTP 2.0, or even 3.0

From CurlHttp.cpp..

// HTTP2 is linked in for newer libcurl builds and the library will use it by default.
// There have been issues found with it use in production on long lived servers with heavy HTTP usage, for
// that reason we're disabling its use by default in the general purpose curl request wrapper and only
// allowing use of HTTP2 from other curl wrappers like the DerivedDataCache one.
// Note that CURL_HTTP_VERSION_1_1 was the default for libcurl version before 7.62.0
curl_easy_setopt(EasyHandle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);

Setting a breakpoint confirms that cesium-unreal executes this line, and there's no apparent way to configure it differently.

Thanks @kring for catching this.

[steve3d]

any updates on this?

[csciguy8]

From what I can tell, this code is unchanged (and still an issue) as of Unreal Engine 5.4.1.