I was trying to simulate GI in a very simple scene and the render view looks ok but the render is messed up with shadows (see attachments). Initially it output correctly. I now see an error message in the Mantra node that says
Command Exit Code: 139

Error: Couldn't remove old operator type definition sesi_temporary::Object/subnet
89268: Fatal error: Segmentation fault (sent by pid 0)
– TRACEBACK BEGIN –
2 libHoudiniUT.dylib 0x000000010729e964 stackTrace() + 244
3 libHoudiniUT.dylib 0x000000010729e5fc signalCallback(UTsignalHandlerArg) + 492
4 libHoudiniUT.dylib 0x0000000107594a30 UT_Signal::processSignal(int, __siginfo*, void*) + 176
5 libsystem_platform.dylib 0x00007fff593c4f5a _sigtramp + 26
6 ??? 0x0000000000000000 0x0 + 0
7 IMG_OpenEXR.dylib 0x00000001235bf1c5 IMG_OpenEXR::readScanline(int, void*) + 565
8 libHoudiniUT.dylib 0x00000001079a3ca5 IMG_File::read(int, IMG_Plane const*) + 661
9 libHoudiniUT.dylib 0x00000001079d6205 IMG_FileFilterConvert::readPlaneScanline(int, IMG_Plane const&) + 117
10 libHoudiniUT.dylib 0x00000001079a3cc6 IMG_File::read(int, IMG_Plane const*) + 694
11 libHoudiniUT.dylib 0x00000001079d7c78 IMG_FileFilterFlip::readPlaneScanline(int, IMG_Plane const&) + 168
12 libHoudiniUT.dylib 0x00000001079a3cc6 IMG_File::read(int, IMG_Plane const*) + 694
13 libHoudiniUT.dylib 0x000000010799cdb9 IMGfindDataWindow(IMG_File*, UT_Rect&, double, std::__1::basic_ostream >*) + 1577
14 libHoudiniUT.dylib 0x000000010799d19f IMGfindAndSetDataWindow(char const*, char const*, double, long long, bool, int, bool, bool, char const*, double, bool, std::__1::basic_ostream >*, std::__1::basic_ostream >*, bool, UT_Options*) + 479
15 IMG_OpenEXR.dylib 0x00000001235c6aa7 IMG_OpenEXR::postCloseAction() + 391
16 libHoudiniUT.dylib 0x00000001079a5cde IMG_File::close() + 222
17 libHoudiniUT.dylib 0x00000001079d31f2 IMG_FileFilter::closeFile() + 34
18 libHoudiniUT.dylib 0x00000001079a5c32 IMG_File::close() + 50
19 libHoudiniUT.dylib 0x00000001079d31f2 IMG_FileFilter::closeFile() + 34
20 libHoudiniUT.dylib 0x00000001079a5c32 IMG_File::close() + 50
21 libHoudiniUT.dylib 0x00000001079d31f2 IMG_FileFilter::closeFile() + 34
22 libHoudiniUT.dylib 0x00000001079a5c32 IMG_File::close() + 50
23 libHoudiniUT.dylib 0x00000001079ce995 IMG_TileFile::close(bool) + 69
24 libHoudiniRAY.dylib 0x000000011e2b793b RAY_TileDevice::close() + 139
25 libHoudiniRAY.dylib 0x000000011e17bca4 RAY_ImagerFile::closeDevice() + 468
26 libHoudiniRAY.dylib 0x000000011e1755f0 RAY_Imager::close() + 16
27 libHoudiniRAY.dylib 0x000000011e2265db RAY_Scene::finishRender() + 59
28 libHoudiniRAY.dylib 0x000000011e22978b RAY_Scene::render() + 2027
29 libHoudiniRAY.dylib 0x000000011e26a44d RAY_SceneIO::doRender(CMD_Args&) + 1661
30 libHoudiniPRM.dylib 0x0000000109b377c2 CMD_Manager::runCommand(char*) + 4146
31 libHoudiniPRM.dylib 0x0000000109b2373e CMD_Manager::internalExecute(char const*) + 3534
32 libHoudiniPRM.dylib 0x0000000109b34c3c CMD_Manager::processInput(CMD_Source*, char const*) + 140
33 libHoudiniPRM.dylib 0x0000000109b355bf CMD_Manager::internalSendInput(char const*, bool) + 1535
34 libHoudiniPRM.dylib 0x0000000109b35cb4 CMD_Manager::sendInputNoLock(char const*, bool) + 68
35 libHoudiniRAY.dylib 0x000000011e263118 RAY_Scene::load(UT_IStream&) + 472
36 mantra 0x0000000105039e56 main + 2694
37 libdyld.dylib 0x00007fff590b6015 start + 1
– TRACEBACK END –
Error: Couldn't remove old operator type definition sesi_temporary::Object/subnet

I tried to delete and recreate the Mantra node and I still get the errors on render that are not on renderview. I am stumped.

Apparently the issue is that render view uses ray traced shadows and mplay or render to disk uses the setting in the file of depth map shadows. If the objects are too small, depth map shadows don’t work correctly. Scaling the objects in the scene fixes this.

I would suggest sticking with raytraced shadows for area light sources. Depth map shadows are meant to be used with point light sources (such as spotlights). Are you still seeing errors in your render? Can you try the latest daily build and see if the error persists?

The errors persisted after latest daily build as well as after deleting houdini_temp from /tmp and deleting the deleting my $HOME/houdini16.5 directory. It goes away with scaling the objects and also is not present if I change the area light's shadow to raytraced. I've created a simpler scene that was not scaled and it did not have this problem, so it must be a combination of number of objects, size of objects, and depth map shadows.

Since this is a crash, please submit the scene with a reproducible case in to support. See the web site for how to submit a bug to support. Tie the case in to this forum post if you wish.