Hi Patrick
We have seen that problem happening on Fortnite but we haven’t been able to find the source of the problem. We are currently working around the problem by deactivating the use of the ISPC code. In the client’s targetRules , you can define the following to compile the code out:
// Disabling ISPC for the legacy codecs due to issues with AVX512 target
GlobalDefinitions.Add("ANIM_CONSTANT_KEY_LERP_ISPC_ENABLED_DEFAULT=0");
GlobalDefinitions.Add("ANIM_PER_TRACK_COMPRESSION_ISPC_ENABLED_DEFAULT=0");
GlobalDefinitions.Add("ANIM_VARIABLE_KEY_LERP_ISPC_ENABLED_DEFAULT=0");
Another way to workaround the problem is to switch to the ACL plugin for the compression of the animation: https://dev.epicgames.com/documentation/en\-us/unreal\-engine/animation\-compression\-library\-in\-unreal\-engine
We are actually doing both methods at the same time in Fortnite.
We have seen the problem happen on AMD chips so it doesn’t seem to be specific to a single chip family. It could still be another manifestation of hardware failure caused by overclocking on the Intel CPU. The following article describes the problem and point toward some useful information: Intel Processor Instability Causing Oodle Decompression Failures
Regards,
Martin