Cycles Development Updates

The height of that particular HDRI is about 6” shorter than the person in that reference photo. Nevertheless, I’ve tested the render across six different HDRIs, with other faces; the conclusion is all the same: the over-uniformity of the SSS surface illumination contributes to a kind of dull artificiality of the rendered skin.

I like your idea of improving fresnel and scattering direction; it’s perhaps a step in the right direction. I’m not entirely certain what fresnel has to do with this effect, as it doesn’t seem tied to view direction so much as light direction. But you may be right about scatter direction.

So in the end I take it that SSS anisotropy isn’t in Blender’s future?

I’d like to finish the anisotropy at some point, but it’s not a priority at the moment.

Fresnel is an effect that happens both when entering and exiting the volume, so that’s for the view and light direction. Often the light direction part is ignored, which can be part of the problem here.

1 Like

Hi @brecht,

Many thanks for developing one of the most versatile 3D renderers available. :+1:

A few questions:

• I love the Random Walk SSS. Will we be able to use it in GPU rendering mode soon?

• When I activate Denoising in CPU + GPU rendering mode (in the nightly Master builds), I get random black buckets in my renderings on MacOS when using an AMD Radeon Pro GPU. Is this a known issue, and could it maybe be solved soon?

Maybe the black buckets are caused by the bad OpenCL support in MacOS? In that case using MacOS Metal in stead could improve Cycles a lot on MacOS. AMD’s Radeon ProRender improved very noticeably after the beta version switched from OpenCL to Metal.

Thanks,

Metin

Random walk SSS is supposed to work on the GPU. But it may be just like the denoising, where we are struggling with bugs/limitations in the macOS OpenCL driver. We don’t currently have a developer to test and improve this platform. Metal could help but it’s a big projects for a relatively small % of Cycles users, so I don’t expect it to happen soon.

Thanks a lot for your swift reply, @brecht, and keep up the great work.

Yes, technically it would be better to ask for help in a new thread under the support section: https://blenderartists.org/c/support

My best guess is that you are using the blender 2012 experimental keymap. I checked, and it uses tab for search. If you want to follow tutorials, then its better to use the default keymap. If you don’t like using right click to select, you can change that in the user settings (some things will work differently though).

I think it also should be mentioned, with CUDA and OpenCL, they are all cross platform. As in, you write once and most of the code should work the same on Linux, Windows and Mac OS.

With Metal, it is a MacOS specific language, which means that you will be targeting just one operating system. Which currently sits around 10% of the current usage – https://www.blender.org/wp-content/uploads/2017/07/blender_stats_2017_year.jpg?x10773

Sadly the relatively minor Blender user base on MacOS is a fact, @doublebishop. Of course I’d rather see Apple increase OpenCL support, or — even better — return to NVidia GPUs, so I could use CUDA again. I’m not a big fan of AMD GPUs so far. My previous Mac was the last model that contained an NVidia GeForce, and before that I used Windows PCs containing GeForce cards. But I quite like MacOS and its stability.

If it helps in your decision making, I work in an industry that is pretty much exclusively Apple, so over the past decade, my 9am-5pm computer has been variations of macPros, where all my home machines have been windows based OEM builds, or more recently custom builds. I find my current macPro (trash can edition) at work no more stable than my current build at home that uses windows10 the majority of the time (had the machine now for over 5 years). If you have a problem with windows, linux seems to run Blender more efficiently (from all accounts that I have read). If linux doesn’t support all the apps you like outside of Blender, set up the machine to dual boot so you have the option to boot windows when you are stuck.

Anyhow, not an anti-Apple post or anything like that, but if you don’t like the architecture/hardware that Apple sports, maybe it is time to put what you want into your computers - hand pick only the best. At this day and age, it’s hard to argue that one OS is substantially better, they all have little advantages, but operating systems are getting more and more the same and offer similar experiences. In my opinion, hardware is king over OS, so invest in the brick and mortar that actually does the heavy lifting.

1 Like

Hi @B-Rae,

Thanks for sharing your point of view. I understand, and I didn’t want to start an OS war, although I was aware of the risk of that by stating that I like the stability of MacOS. :wink:

I’ve been working with Windows from the mid-1990s (before that I was a Commodore Amiga fanboy :slightly_smiling_face:) up to 2014. One of the main reasons I stuck with Windows for so long is because I was a long-time 3ds Max user. But when I decided to switch to Blender I could also cross over to an iMac.

I’m not an Apple fanboy, but I just like their eco system and the user-friendliness of MacOS. Also, a lot of tools are already covered by the OS, while in Windows you have to install a third-party tool for just about everything. I’ve become a bit too lazy for that.

In my personal experience, I’ve been having noticeably less crashes using MacOS than using Windows, maybe because hardware and OS are more tuned to each other. But it’s been four years since I last worked with Windows, so Windows 10 has probably become better and more stable than preceding Windows versions.

Regarding hand-picked custom PC hardware: I’m a hardware nitwit, and I hate the noise of fans in workstations. :slightly_smiling_face:

Please note that I respect anyone’s OS choice and hardware choice, and don’t want to disturb the Cycles thread with this subject matter. My apologies about this hiccup, and please continue the Cycles discussion.

Hey @Metin_Seven, totally fair response, and I completely understand. Like I said, I am not arguing against anything, just trying to find potential solutions if it was possible.

Back to cycles, as we were.

1 Like

Appreciated, @B-Rae! :+1:

Lukas Stockner has overhauled the IES Light patch and anticipates it getting into master soon.
https://developer.blender.org/D1543#79375

This may or may not be something that will be 2.8 only (2.7x is near the end of the line).

3 Likes

It’s going to be 2.7x as far as I can tell, there’s not really anything in there that needs 2.8 (as opposed to the disk lights for example, which include Eevee support)

2.7x is going to be updated ?

I don’t think there’ll be another 2.7 release, but the master branch and therefore nightly builds still technically are 2.7.

That’s great news because it will still take a lot of time before 2.8 is as polished as 2.79 and till then we’ll have to use 2.79

Disk and Ellipse shapes for area lights (from Lukas Stockner)
https://lists.blender.org/pipermail/bf-blender-cvs/2018-May/108802.html

A new arctan 2 operator for use in the math node (Also from Lukas Stockner)
https://lists.blender.org/pipermail/bf-blender-cvs/2018-May/108806.html

A note about the first one, it comes with an equivalent implementation for Eevee so it will only be found in the 2.8 branch (so it won’t be in master until the big merge).

1 Like

They’re a long way off from 2.8 being production quality, so not having it in the stable branch is professionally amateurish to be kind.

Get it in the hands of your largest audience first and flush out any issues, then when 2.8 is solid greenlighting a switchover is painless.

On a different note, after reading the comments on the latest patch for IES Light patch the dialogue on how to work with False Colors brought my thoughts back to the one issues that NONE OF THESE DEVS seems to deal with:

Technical Writing.

The Docs for Blender are abyssmal, and most of the value is gleened by skimming countless hours through Dev dialogues.

The lack of responsibility by the developer writing features and not publishing how to implement these features correctly, on any object, in any scene, is a disease at this point.

Having to search BlenderExchange for solutions should be the last source, not the primary one. Fix it.

It’s great you have new offices for development. Require the staff to write documentation.

1 Like

An analytical tube light would also be nice. Sounds like a “simple” extension of a disk light. Any plans of making lights have a falloff (similar to spotlights), and in what way will the new ones support textures?