I've been reading a bit more about Packer and indeed it should be a fairly easy thing to setup a docker image that matches the VFX platform.
One reason I've been angling towards Docker is that NVidia (which most VFX studio have lots of hardware from) provides a very rich set of base images that allow us to build against GL and CUDA libraries, which some VFX packages have optional dependencies to (especially OpenSubdiv).
Having pre-built GL-enabled variants of these packages might be desirable, especially Qt which is quite tricky to build properly and all the vendors provide in slightly different variations...
That said, to get started on the official VFX platform 2018 you would just need a vanilla CentOS-7 VM/docker image and run this:
yum install -y centos-release-scl-rh
yum install -y devtoolset-7-toolchain make
Then install cmake using this:
(the cmake in centos7 is way too old...)