EEVEE Hair Count Limits

Hey folks!

I’ve been searching around for an answer to this, but to no avail, so I figured I’d ask here and see if anyone has any insights.

I’ve been using 2.8 and Eevee a ton lately, just to sort of explore and play around – I’m well aware that it isn’t yet fully feature complete and all. The one limitation I seem to have run into is hair.

I can get it to look decent enough in Eevee, but there seems to be a limit on the number of hairs, based on complexity. So just the simple, default hair lets you do around 16k total, but if you add extra steps and other intricacies, that number drops.

Once you cross that magic number, the entire hair system simply vanishes. I’ve attached a simple demo video to show what I mean.

As far as I can tell, this has never been an issue in 2.79. It would get REALLY laggy, if there was too much hair on-screen, but it would at least still render.

Does anyone know if this is some new 2.8 safeguard to keep the viewport fast? If so, can it be disabled? A bug? I haven’t seen anyone talk about this (although it’s entirely possible I just suck at searching), and it seems like something a lot of people would be affected by.

I use hair a lot in my work, whether for its intended purpose or for procedural stuff like trees and grass, so having to work around some uncrossable limit would be a bummer.

It is definitely a Bug just on your end! I can go up to 1mio (prob. even further) hairs and still have a usable framerate and of course the hairs don’t dissapear! Maybe you PC specs to low?!

It may be a MacOS bug, then. Because I have a Core i9, 32 gigs of RAM and a Vega 20 card. Not immensely beefy, but certainly no slouch, either.

Ok than its certainly not the graphic card, because I have also a radeon vega 64 but on Win 10 Pro. So maybe is really a MacOS bug. If you don’t find a solution, I would suggest you to open a bug report.

I have also a open bug report, because on my end the shadows of alpha image textures doesn’t work if I set the blend mode to alpha clip or hashed. So I’m curently unable to produce proper trees or hair with alpha maps. Its Beta, so there are still a lot of Bugs…

In terms of Eevee development, the MacOS drivers developed by Apple are turning out to be almost as bad as the ones used for Intel Integrated graphics.

Check out the logical gymnastics Clement has to do to fix a few of the bugs.
https://lists.blender.org/pipermail/bf-blender-cvs/2019-February/120239.html

Even worse, Apple has largely abandoned OpenGL development and is now focusing exclusively on Metal (so Mac. users are set to face a deteriorating 2.8 experience until a new backend is built).

Yikes! Well, guess I’ll keep an eye on how 2.8 progresses and consider potentially hopping to Linux for blender work.

I currently have my MacBook pro for the creative side of the work and a PC tower I’m building for the heavy lifting rendering piece of the puzzle.

Thanks for your answer!

This is a limitation of the current workaround (as linked by @Ace_Dragon). I will modify it to make it work with arbitrary number of hair/verts.

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ugh this apple situation is growing progressively worse. :frowning:

as the limit appears to be per-particle-system and not scene global, a not particularly elegant work around I’ve found has been to duplicate the system several times with different randomization seeds to fill things out. although if any grooming work has been done it has to be repeated for each system.

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If things are that bad, then its probably better to set up your mac as a dual boot system, and run blender under linux or windows.

Yeah I have. and I don’t fault blender at all for the situation.

I’m just lamenting that apple is pulling this nonsense on people who used to like the Mac platform. Only a handful of cross platform developers are going to invest the effort in maintaining these sorts of closed proprietary frameworks when Macs are a relatively small market. I can’t help but feel they’re shooting themselves in the foot (as evidenced by its becoming almost impossible for me to continue using the platform after being a user for 15 years)

Yeah, looks like I may have to dual boot w/ Linux, if this is the way things keep heading. Still, kudos to the Blender devs for all their awesome work battling this nonsense and trying to get things into as good a shape as possible. Very much appreciated!

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Just as an update for anyone interested – the issue is now fixed. Everything’s working brilliantly. Huge thanks to the Blender dev crew!

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