Segmentation Fault OptiX raycasting

Gaming and Visualization Technologies Visualization OptiX
1

First my apologies if this is not the proper place to post this question.

I am very new to OptiX and rendering in general, but I am trying to determine if OptiX would be appropriate for a project I am working on for research. I have been working through the OptiX 7 Siggraph Course and concurrently digging through the SDK to try to better understand it.

I am having issues with the ray casting example. The example runs fine with the default settings(duck). However, I tried to add my own mesh and received a segmentation fault error. So I tried with some of the other provided models and got it to run for the water-bottle example, but also received segmentation faults for the plane and woman examples. This example seems to be very close to what I was trying to do, so I was hoping to use this as a jumping off point. Any help in understanding the issue and/or debugging is greatly appreciated.

Below is the ouptut:

/optixRaycasting -m …/…/SDK/data/Surface/surface.gltf
No file prefix specified, using default file prefix (output)
Processing glTF buffer ‘’
byte size: 5743224
uri : surface.bin
Processing glTF mesh: ‘geometry_0’
Num mesh primitive groups: 1
Num triangles: 238602
Has vertex normals: true
Has texcoords_0: false
Has texcoords_1: false
Has color_0: false
[ 4][ KNOBS]: All knobs on default.

[ 4][ DISKCACHE]: Opened database: “/var/tmp/OptixCache_benjamin/optix7cache.db”
[ 4][ DISKCACHE]: Cache data size: “3.6 MiB”
[ 4][ DISKCACHE]: Cache hit for key: ptx-129520-key64f683a73bdcb60323287ff636d6f4f8-sm_86-rtc1-drv550.54.15

[ 4][ COMPILER]:
[ 4][ COMPILER]: Info: Pipeline statistics
module(s) : 1
entry function(s) : 4
trace call(s) : 1
continuation callable call(s) : 0
direct callable call(s) : 0
basic block(s) in entry functions : 130
instruction(s) in entry functions : 3635
non-entry function(s) : 0
basic block(s) in non-entry functions: 0
instruction(s) in non-entry functions: 0
debug information : no

[ 4][ COMPILER]: Info: Pipeline statistics
module(s) : 1
entry function(s) : 4
trace call(s) : 1
continuation callable call(s) : 0
direct callable call(s) : 0
basic block(s) in entry functions : 130
instruction(s) in entry functions : 3635
non-entry function(s) : 0
basic block(s) in non-entry functions: 0
instruction(s) in non-entry functions: 0
debug information : no

Segmentation fault (core dumped)

2

Yes, the glTF loader routines inside the simple OptiX SDK examples are not supporting all features allowed by the glTF specifications.
Please see this thread for explanations of some of the limitations:
https://forums.developer.nvidia.com/t/vtk-optix-triangle-mesh-write-read-operations/293966/2

I would need to debug into what happens with the biplane and woman models.
(My GLTF_renderer example can load these without problems.)

3

@droettger Thank you for the reply. There was a lot of information to parse through in there. I ended up getting it to work using tinyobj loader, but I will continue to dig through these examples to see if I can come up with a better solution. I am thinking in the long term, passing the mesh directly from the program that generates is better than saving / opening a file.

Thanks again!