_rtBufferGetDevicePointer caught exception: Assertion failed

Gaming and Visualization Technologies Visualization OptiX
1

Hello,

I want to modify an OptiX buffer within a CUDA kernel, but getting the device pointer somehow fails in certain cases.

Please have a look at the following (simplified, yet working or crashing) examples:

This one works:

optix::Buffer buffer = context->createBuffer(RT_BUFFER_INPUT, RT_FORMAT_FLOAT, 100);
CUdeviceptr ptr;
buffer->setSize(1000);
buffer->getDevicePointer(0, &ptr);

This one crashes:

optix::Buffer buffer = context->createBuffer(RT_BUFFER_INPUT, RT_FORMAT_FLOAT, 100);
CUdeviceptr ptr;
buffer->getDevicePointer(0, &ptr);
buffer->setSize(1000);
buffer->getDevicePointer(0, &ptr);

Unknown error (Details: Function “RTresult _rtBufferGetDevicePointer(RTbuffer_api*, unsigned int, void**)” caught exception: Assertion failed: [2097357])

Can you tell me why?

2

I’m taking a deep look at this. I think you got a bug…

I’ll let you know (and possibly fix) as soon as possible.

3

The bug has been fixed and it will be shipped into next OptiX release.

Thanks m_sch, we really appreciate your help! :)

4

Great, I am looking forward to the next OptiX release. Will this happen before GTC2014? I submitted a talk proposal and (depending on the new features of) OptiX 4.0 (?) might be interesting to evaluate before that.

5

The next version of OptiX will contain support for CUDA 5.5 as well as numerous bug fixes and new features (no spoilers :). Unfortunately I can’t commit on a firm release date, but we hope to get it out shortly.