There are a few important changes with the introduction of V-Ray Next concerning V-Ray GPU and the support for OpenCL (on all platforms) and macOS in particular.
OpenCL support in V-Ray GPU
As software developers, our goal is to make our software run on as many platforms as possible and as efficiently as possible. This benefits everyone. Historically, we have been dedicated to supporting almost any open standard possible — OpenEXR, OpenVDB, OpenColorIO, OpenCL, etc.
V-Ray GPU has been the first — and mostly the only — renderer to support OpenCL for many years. Starting with V-Ray Next, we have removed support for OpenCL.
There are several reasons for this decision. First, most hardware and software vendors have decided to divest or deprecate their support for OpenCL, for example:
- Apple officially deprecated OpenCL with macOS Mojave
- NVIDIA has never supported the modern OpenCL 2.0
- AMD also stopped investing in OpenCL.
Second, as software developers, it is our responsibility to make sure that our users get the best experience possible and can utilize their hardware to the maximum. Unfortunately, we do not believe OpenCL helps us with this goal.
GPU support on macOS starting with V-Ray Next
With V-Ray GPU Next, CUDA rendering on macOS is still there, but its status is changed to “unofficial” for reasons we'll try to explain below.
Apple devices don't come with NVIDIA GPUs installed and there is no official support by Apple for NVIDIA eGPUs on macOS devices. This makes it really hard for us to develop code and provide adequate support. We have tried the Metal API and, currently, it is not a viable option for our ray-tracing code. If this changes in the future, we will surely consider it.