Octane and Dynamic Hair
Chris Fox Art
Posts: 380
I've had an issue with Carrara some time ago but didnt knew what exactly the issue was.
Every time i wanted to do an octane render with a special scene it crashed, an error has... and i could only click cancel or ok and with both options carrara will be closed.
Right now i know what the problem was but i dont know how i can fix it.
It seem to be the dynamic hair that crashes Carrara, if there are too much hair groups or maybe too much hairs, Carrara will crash when i do an octane render, a normal Carrara render won't have any issues.
Does anybody else have these problems?
I was sitting a fully day on a haircut and it's a bit frustrating that i canot do the render in octane :\
Comments
How complex is the hair? If you take the number of hairs multipied by the number of segments per hair, you get the number of Octane hairs this will generate. If you are talking about a human hairstyle, a typical head has around 100,000 hairs so you needn't go higher than that, and can probably get away with less (but still tens of thousands). Number of segments is probably going to be between 20 and 50. I have no issues rendering this with my 2GB card.
I have tried to make a similar hair style like dolce hair from v4 just for Genesis 2 but I also got the issue using the dolce hair on v4 while Carrara have no issues with that, octane have and Carrara crash.
https://www.daz3d.com/dynamic-dolce-hair-for-v4
like in dolce hair I used many hair groups but I don't know the amount of hair at all right now, need to count them together when I'm home
by the way, I am rendering with 2x sli GeForce gtx 560 to ultra charged edition (over clocked with 2gb per card)
I can't see why the number of hairs groups would matter (although I have been wrong on things before!). I haven't got that particularl hair, but I tried another by 3DCelebrity which has 8 hair parts and that rendered fine - I had to set the visibility of all the hair parts to 100% as Octane takes its hair information from what is displayed in the Assemble room.
If I'm not wrong dolce hair have more than 10 hair groups but the amount of hair at all should be less than 100.000.
could it also be a matter of the segments per guidelines?
i will take a closer look when I am finished or will send you my generated hair for Genesis 2 for testing.
i also took a look on the website of octane for any updates, there are some for stand alone but not for Carrara plugin, I updated the standalone but no changes about this issue.
Yes, I would be happy to test it for you. The Octane Hair primitive is essentially just one segment of hair - a start and end coordinate and a thickness. So a Carrara hair with 20 segments will convert to 20 Octane hair primitives. And a full head of hair with say 40,000 hairs each with 25 segments will convert to one million Octane hair primitives. But that is well within the limits of even my modest 2GB card, actual geometry generally takes up much less space than the textures in a typical scene.
Dolce Hair have 27 Hair groups
Group 1: 10 segments, 2400 hairs
Group 2: 10 segments, 1200 hairs
Group 3: 10 segments, 1200 hairs
Group 4: 10 segments, 4000 hairs
Group 5: 8 segments, 1200 hairs
Group 6: 8 segments, 1200 hairs
Group 7: 32 segments, 7000 hairs
Group 8: 22 segments, 200 hairs
Group 9: 8 segments, 200 hair
Group 10: 64 segments, 2100 hair
Group 11: 8 segments, 120 hair
Group 12: 36 segments, 550 hair
Group 13: 44 segments, 2200 hair
Group 14: 44 segments, 2400 hair
Group 15: 64 segments, 1600 hair
Group 16: 64 segments, 300 hair
Group 17: 84 segments, 200 hair
Group 18: 56 segments, 1000 hair
Group 19: 98 segments, 360 hair
Group 20: 10 segments, 200 hair
Group 21: 32 segments, 600 hair
Group 22: 86 segments, 700 hair
Group 23: 64 segments, 34 hair
Group 24: 4 segments, 50 hair
Group 25: 4 segments, 50 hair
Group 26: 98 segments, 200 hair
Group 27: 84 segments, 200 hair
that are all segments and hair per group, guide lines and segments per guide shouldnt do any problem i think.
thickness is medium
so its 1.062 segments and 31.464 hairs if i have counted correctly, that will be 33.414.768 generated hairs?
No, nowhere near that many (but my, what a lot of groups!). For each group, you need to multiply the number of hairs by the segments per hair to get the number of "Octane Hairs" that will generate. And then add up the totals for each group. I was able to throw these into a spreadsheet, remove the text and do this quite quickly and the total comes to 1,044,816, which should not be an issue for Octane to handle. I don't have that particular hair so I can't test it myself.
i've send the mail out with the hair
Hmm, I've got dolce hair I'm pretty sure. I haven't ever tried it in Octane, but will give it a try when I have a chance to see what happens.
I've never looked that closely at the hairstyle, but I've gained a bit of expertise in creating my own dynamic hairs since back when I bought it, I honestly can't think of any reason for any hairstyle to have so many hairgroups, certainly not one that's as fairly simple as this one. You've got me curious...
Yup, just tried it and Dolce hair loaded fine, but when I opened the Octane window Carrara crashed with 'an error has occurred'.
I have been doing some tests and it does appear to be the number of hair groups that is an issue, rather than the total number of hairs. Anything above around 8 groups seems to present issues. I will report this to Sighman to see if he has any ideas on what the issue is and how to resolve it.
Good to know that it's not an issue with my system or so :)
But i am still wondering why Carrara crashes in octane with this hairstyle and if there will be a fix for it from Octane or Carrara.. (Well, Octane for Carrara is still in the beta right?)
Sighman is the developer for Octane4Carrara that PhilW mentioned above. While Octane4Carrara plugin is still in beta, Sighman had previously believed dynamic hair was fully supported with no problems (none of us had managed to run into this one before). But sighman is very responsive (and very smart!) at solving these thiings, so I have great hope that there will be a fix. In the meantime I can't get over how many hairgroups there are in this hairstyle, I wonder what 3dcelebrity (the creator) had in mind as a purpose for so very many hair groups. I can't help thinking I could design a very similar hairstlye fairly quickly with less than 3 hairgroups. I'll give it a crack when I get a little free time to see what I can come up with.
I have now had a response from Sighman (Octane Render for Carrara developer) and he set a limit of 8 groups thinking that no-one would ever need more than that! He is looking at fixing it, I think it should be a pretty simple fix, which will get these hairs working.
Not had a solution yet from Sighman, but I wanted to share my latest render, as I was pleased with the look of the hair - I am still delighted that Octane will now render Carrara's hair, it is a dream come true for me! The hair is a modified Adrea Hair and my Octane Shaders for Carrara hair have been applied.
Stunning Phil!
Thank you guys!
Phil,
To repeat what is said above, stunning and impressive. The hair looks touchable.. My screen keeps getting in the way - ouch. Before I get accused of digital fondling, let me say, kidding aside, to my eye, that hair is as realistic and vibrant as it is possible to get on a screen. And, no kidding, it does look touchable.
Really nice work Phil,
Starboardtack
Very nice indeed Phil