Hello and thanks for maintaining Blender in Debian! According to the Blender [manual], denoising can be accomplished on the CPU by using Intel [Open Image Denoise], or on the GPU by using an algorithm implemented within the Optix acceleration engine. [manual]: <https://docs.blender.org/manual/en/latest/render/cycles/render_settings/sampling.html#render-cycles-settings-viewport-denoising> [Open Image Denoise]: <https://www.openimagedenoise.org/> If I understand correctly, Optix requires an NVIDIA GPU and NVIDIA proprietary drivers: that's not an option on my box, where I have Intel integrated graphics (with Intel DFSG-free drivers). Hence, I thought Intel [Open Image Denoise] could be the way to go. However, it seems to me that the blender Debian package is built without support for Intel [Open Image Denoise]. Is this the case? Why? Because Intel [Open Image Denoise] is not (yet) packaged for Debian, perhaps? Maybe a RFP bug could be filed and let it block this bug report. I am quite ignorant about Blender, sorry about that. In case I am misunderstanding anything, please clarify. Thanks for your time and patience! P.S.: by the way, I searched the web a little while: do I understand correctly that it is currently not possible to make Blender use an Intel GPU for rendering?
Ciao! Il sab 26 feb 2022, 20:15 Francesco Poli (wintermute) < invernomuto@paranoici.org> ha scritto: Please, have a look at [1]. Cheers. mfv [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=975318#10
Ciao! :-) Thanks for your very prompt reply. [...] [...] [...] [...] I see, and I agree with Debian Policy that convenience copies of code should be avoided, whenever possible. However, I think we are *not* talking about a convenience copy here. According to the upstream [issue] you cited, Intel Open Image Denoise includes a modified version of oneAPI Deep Neural Network Library, and cannot work correctly, if linked with the official oneAPI Deep Neural Network Library. [issue]: <https://github.com/OpenImageDenoise/oidn/issues/107#issuecomment-889049772> That does *not* seem to be a convenience copy. It looks like a *necessity* (modified) copy. I don't think that packaging Intel Open Image Denoise for inclusion in Debian (with that internal modified copy of oneAPI Deep Neural Network Library) would be against the Debian Policy. For instance, I personally saw a similar situation with Paraview that embeds its own copy of the VTK library. It was [explained] to me that the specific version of VTK is needed for Paraview to work correctly. [explained]: <https://public.kitware.com/pipermail/paraview/2006-October/003884.html> I [raised] the issue, while Paraview was being packaged for inclusion in Debian, but Paraview needs its own specific version of VTK and was included in Debian without linking with the already packaged VTK library. As far as I can see, the Debian package still includes its own VTK. [raised]: <https://bugs.debian.org/462631#39> Long story short, I would like to encourage you to package Intel Open Image Denoise (with its internal modified copy of oneAPI Deep Neural Network Library), if you still feel like doing so.
I just tried a clean install of Blender on Trixie, fully patched as of 29th July, based on Trixie RC2, and a clean machine. On switching from Eevee to Cycles, and trying to render, I got a message that Blender wasn't built with denoise support (which is consistent with the current issue), and it failed to render. Once I unticked denoise, in the render settings (two places, although maybe only one was needed), it rendered the image properly. Unless and until the current wishlist item is implemented, I believe the default should be with denoise off. Unless there has been a change since yesterday, this will be 4.3.2+dfsg-2, and the amd64 build. (I think this is a minor bug, rather than a wish list item, so I might create a new report, for this.)