OffscreenRenderer and threads

[TimTreurniet]

Hi, I have a program where I run some code in seperate threads. Within these threads, I create an OffscreenRenderer, add a mesh, and render an image and depth image. This works for the first thread, but fails for the next with the error below when initializing a new renderer within the thread. Initializing the renderer within the main thread causes the same crash when the thread calls the render_to_image() function. I believe this issue could be fixed by closing the renderer when the thread finishes, but I do not see a function to do this. Anybody have any ideas?

The thread is started like this, and only one pipeline runs at a time

thread = threading.Thread(target=run_pipeline, args=(some_args))
thread.daemon = True
thread.start()

N5utils17PreconditionPanicE
in JobSystem::ThreadState &utils::JobSystem::getState():263
reason: This thread has not been adopted.

#0	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13eefb1120 _ZN5utils6TPanicINS_17PreconditionPanicEE5panicEPKcS4_iS4_z + 336  
#1	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13eefaeb98 _ZN5utils9JobSystem8getStateEv + 280  
#2	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13eefaea01 _ZN5utils9JobSystem3runERPNS0_3JobEj + 17  
#3	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13eeece244 (null) + 139723589608004  
#4	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13eeed3d04 (null) + 139723589631236  
#5	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13eeecd7e1 _ZN8filament12ColorGrading7Builder5buildERNS_6EngineE + 209  
#6	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e7e554f3 _ZN6open3d13visualization9rendering12FilamentView15SetColorGradingERKNS1_18ColorGradingParamsE + 867  
#7	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e7e558ec _ZN6open3d13visualization9rendering12FilamentViewC2ERN8filament6EngineERNS1_23FilamentResourceManagerE + 284  
#8	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e7e559c4 _ZN6open3d13visualization9rendering12FilamentViewC1ERN8filament6EngineERNS1_13FilamentSceneERNS1_23FilamentResourceManagerE + 20  
#9	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e7e4971e _ZN6open3d13visualization9rendering13FilamentScene7AddViewEiijj + 142  
#10	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e7e2c55f _ZN6open3d13visualization9rendering11Open3DSceneC2ERNS1_8RendererE + 335  
#11	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e5301e68 (null) + 139723426242152  
#12	pybind.cpython-38-x86_64-linux-gnu.so     0x7f13e5086745 (null) + 139723423639365  
#13	python3.8                           0x563d467408ee (null) + 94821175003374  
#14	python3.8                           0x563d4673575f _PyObject_MakeTpCall + 959  
#15	python3.8                           0x563d4676aa9a (null) + 94821175175834  
#16	python3.8                           0x563d4673bb19 PyObject_Call + 793  
#17	python3.8                           0x563d466e04d3 (null) + 94821174609107

[dancergraham]

Hello,
I ran into a similar problem running the OffScreenRenderer from Django - if the user refreshed the page before the thread had finished then it crashed the main thread. My workaround at the moment is to use multiprocessing to start a separate process - this avoids the problem of crashing the main thead.

from multiprocessing import Process, Manager

manager = Manager()
results = manager.dict()
kwargs = {..., "results": results}
p = Process(target=my_function,
            kwargs=kwargs
            )
p.start()
p.join()

[errissa]

@TimTreurniet The OffscreenRenderer shuts down the rendering back end when it is destroyed so it should be possible to do what you are trying to do. Could you share your run_pipeline function?