I have two command buffers that draw stuff. I am certain that I need synchronization, otherwise they interfere with each other. For instance, my one command buffer is for drawing high resolution screenshots. Some times it works, but most times it spits out a black image.

I've tried vkQueueWaitIdle, vkDeviceWaitIdle, image memory barriers, pipeline barriers, and fences. I cannot get anything to work. Any ideas?

The code is at:

https://github.com/sjhalayka/sw_partial_reflectivity

It turned out to not be a synchronization issue. It was a driver timeout issue. To fix this we'll need to break the screenshot into smaller shots, then write them all to a PNG file when done.