In This Earlier Posting, I had written that I had used a benchmarking tool named “LuxMark”, to test whether my GPU even works, on the computer which I name ‘Plato’. In the process, I ran across the discovery, that there exists a type of rendering-engine named ‘LuxCoreRenderer’, which is a ray-tracer, but which will do its ray-tracing with code, that runs under OpenCL.
I had assumed that the benchmarking tool was free, but that users would need to be paying customers, before they can use ‘LuxCoreRender’, to render their own scenes. To my great approval I’ve discovered that LuxRender and LuxCoreRender are also, Free, Open-Source Software. But to my disappointment I’ve learned, that there is no feasible way in which I could use that, on ‘Plato’.
The reason is fairly straightforward. The devs have renamed their renderer, from LuxRender to LuxCoreRender, at which point they also carried out a rebuild of their code, so that version 1.6 was discontinued, and ‘a cleaner build’ was started, as version 2.x . In order to make practical use of a rendering engine, I need a GUI, to create scenes for that engine to render. Well, LuxCoreRender has as minimum requirement, Blender v2.79b , while the Blender-version I have installed on ‘Plato’ is only v2.78a . The requirements that the devs state is strict, because Blender versions before 2.79 contained a bug, which would cause crashes. Not only that, but in this case, a user-space application would crash, for which there are considerable processes running on the GPU, which can cause severe memory-leaks, as I wrote Here.
Now, there does exist a stand-alone version of LuxCoreRender, v2.x , which in fact runs on ‘Plato’, but which remains rather useless to me, because it can only load and then render scene-descriptions, which have been stored to a file which is totally based on Lux, and not on any other standards.
One way in which I did try to work around this, was to download the source-code to LuxRender v1.6 – which is no longer supported – just so that maybe, I could get that to work with Blender v2.78a . And the main problem I ran in to, is that LuxRender depends on “Embree v2″, while the version of Embree which is current, is v3. Thus, there are two ‘#include’ lines at the heart of the LuxRender v1.6 source-code, which specifically ask for Embree v2, and even if we were to edit those, to ask for v3, there would be fatal compile-errors, because the header files don’t match.
I have an additional issue with LuxCore v2, standalone. By default, it detects that ‘Plato’ possesses 8 CPU cores, and will use all 8. What modern software does not account for, is that on CPUs such as the Intel i7 950, the 8 stated cores were threaded as 4. What this means is that the software should really only use 4 cores maximally, in order to run separate jobs, but software often asks for all 8.
Further, if all 8 virtual cores are being used 100% on ‘Plato’, a serious overheating issue eventually ensues. At least with BOINC Projects, I had the ability to throttle back CPU usage, to 1 or 2 cores per project, so that continuous use would not cause any overheating issues. With RenderCore taking 8/8 cores, the CPU temperature inches above 80⁰C, and that is too hot for me to find safe.