MDL - compiled ptx OptiX problem


While trying to render MDL material compiled with MDL SDK I get following error:

RuntimeError: Unknown error (Details: Function "RTresult _rtProgramCreateFromPTXString(RTcontext, const char*, const char*, RTprogram_api**)" caught exception: Compile Error: Unknown usage of symbol: _global_const at: [ Instruction:   %93 = extractelement <4 x float> %92, i32 0, !dbg !13, contained in basic block: LBB0_3, in function: carbon_composite_carbon_composite_surface_scattering_init_ptx0xdcb871bb933c49c0, in module: Canonical_carbon_composite_carbon_composite_surface_scattering_init from (api input string) associated DI info (Dir/File/Line): OPTIX/generated/ generated 98, LL file line and column: 98:1 ])

Error appears with compute capability grater than sm_30. Below I’m attaching comparison of two ptx lines (from sm_30 and sm_50). Lines like following are the only difference between ptx files generated in two sm’s. {%f133, %f134, %f135, %f136}, [%rd52]; //sm_50 {%f133, %f134, %f135, %f136}, [%rd52]; //sm_30 was introduced in sm_32.

Do you have any suggestions?


Is that still with this configuration you gave in another post?

Ubuntu 18.04.2 LTS
Driver Version: 430.26
CUDA Version: 10.2
GeForce RTX 2080
Optix 6.0.0
mdl-sdk-317500.2554 (prebuild)
gcc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0

If yes, could you try OptiX 6.5.0 with the required driver versions instead?
There have been changes to the PTX parser which might affect this.