Rendering hair times

SteveM17

Hi, I was wondering if there are any tips/tricks/methods to rendering hair quicker? It seems to take a ridiculous amount of time compared to other things. For example, a while ago I rendered a v4 figure with clothes and jewellry but no hair and it took about a minute and a half in 3delight. I added hair and it took almost 30 minutes to get a third of the way through the render, which I cancelled as it was taking too long. So, any ideas to get quicker hair renders, please?

Cheers

hwgs1971

I'm no expert, but I recently figured out dForce hair takes much longer to render than non-dFroce hair. So when I am setting up a scene I use non-dForce, then when I am ready for the final print I replace the hair with dForce. Some dForce hair, like Rockz, takes a lot longer than other dForce hair, like dForce Side Bob. Also Jam hair times can vary wildly depending on the pose. And I have a Corsair One with a 2080ti and struggle with these times. I don't know if a 30xx series card is worth it because I've only seen 20% increase in render times in reviews. 30 minutes, 24 minutes,...what's the difference, not enough to justify an expense like that.

onix

There is no surprise that hair takes so long to render as character geometry contains 20 000 polygons and some average hair contains 200 000 polygons with lots of transparency and reflections. putting one hair in the scene is comparable to putting few Genesis 8 figures.

Older hairs from victoria4 models render much faster  since it usually uses a different kind of geometry 

3delight rendering speed greatly depends on the lighting. more light sources means slower rendering. I don't use 3delight anymore so can't tell more details, but I think at this time you can just use filament instead of 3delight.

hwgs1971 said:

I'm no expert, but I recently figured out dForce hair takes much longer to render than non-dFroce hair. So when I am setting up a scene I use non-dForce, then when I am ready for the final print I replace the hair with dForce. Some dForce hair, like Rockz, takes a lot longer than other dForce hair, like dForce Side Bob. Also Jam hair times can vary wildly depending on the pose. And I have a Corsair One with a 2080ti and struggle with these times. I don't know if a 30xx series card is worth it because I've only seen 20% increase in render times in reviews. 30 minutes, 24 minutes,...what's the difference, not enough to justify an expense like that.

You probably used incorrect terminology here, as it is not dForce hair but strand based hair. that kind of hair has just a ridiculous amount of geometry as it models every hair strand. but it looks pretty realistic 

dForce can be applied to any hair. just like it can be applied to any item

content designers unfortunately do not give a shit about optimization but I think it may be a good idea to mix strand based hairs with normal old-style hair as strand hair is pretty good for bangs but not that much use for the other places

Scott Livingston

For 3Delight renders, I did a thread a while back that might be useful: https://www.daz3d.com/forums/discussion/17656/hair-tutorial-for-ds4-users

One method you can use to speed things up (in 3Delight) is to turn Occlusion off in the Surfaces pane (if your hair uses the UberSurface shader). Turn raytracing off as well to speed things up further. However, turning off these settings can sometimes negatively impact realism; you can use a method called phantom shielding (or fantom occlusion) to bring back realistic occlusion/shadows without slowing things down too much. The 4th post in the thread linked above gives detailed instructions.

It's been a while since I played around with this, since I mainly render in Iray, but if you have any questions about it, please let me know!

SteveM17

Thanks, I'll have a look into that. I don't try for photorealistic, so less fancy settings are fine with me.

Cheers.