Problems with scalable rendering auto-activation logic for serial engines

[markcmiller86]

Describe the bug

I am not seeing VisIt automagically switch into SR mode when loading 32k x 32k 2D rect mesh from NIF via Xdmf reader. I worry that the polygon counting logic doesn't account for rectilinear meshes properly.

As an aside, maybe the NIF image data should really be loaded up as a bonified vktImageData object?

Well, hmmm...wait a minute. I was doing this with a serial (remote) engine. I think in serial, it decides never to do SR mode. I think that logic exists because it was assumed that serial engine and viewer are typically running on same host and we should never software render (in the serial engine) process when we can hardware rendering in the viewer.

But, in my case, I was running a remote serial engine (a very large dataset that I had pared down using SIL restriction) and I surely don't want all that data going over the network.

As an aside, the Information tab in SR mode dialog is supposed to update the count of polygons. When in SR mode, it is showing the count of polygons in the viewer, not the engine. It should show the polygone count from the engine.

[markcmiller86]

You can watch what happens when I do this in the attached video.

https://github.com/visit-dav/visit/assets/5720676/b994a6a9-5f6d-4469-86de-b78ce2f6c3d3

[cyrush]

Discussion Takeaways:

• In this case parallel engine will work well.
• We do want to explore if serial engine can use SR.
• We may not be able to launch a parallel engine with 1 task b/c our launcher is too smart.