Cycles Strand Rendering

[Mauricio_Pampin]

Jus though I’d share this scene I’ve been working on. I was planing to use BI but when I saw this post I couldn’t resist trying it on cycles!! Great patch!!

The pebble are also hair strands. I just play around with the hair thickness

[wondrs]

Had to try it to. Also my first model in blender ( using maya before).

[Farmfield]

@Kent

Awesome work, as always.

@ejnaren

Well hes missing brains thats for sure. When he turns around there’s a split second where you can see light through hs ear…

Seeing which angles this happens, I think it’s coming from his eyes, either that or Kent placed a prisma w. glass shader inside the model just to throw us off… xD

(absolutely hilarious, either way)

[troubled]

That’s interesting, I always thought he was just a render of a younger Lloyd Bridges! ><

[etoven]

@Mauricio_Pampin

Jus though I’d share this scene I’ve been working on. I was planing to use BI but when I saw this post I couldn’t resist trying it on cycles!! Great patch!!

[ATTACH=CONFIG]211965[/ATTACH]

The pebble are also hair strands. I just play around with the hair thickness

Great render! Although I find the subject matter a little disturbing… Maybe that’s the point…

[aermartin]

@wondrs welcome! and nice render

[rcpongo]

@wonders

Nice render. You should increase the steps setting a bit though to put some more segments in the long hairs.

[BroadStu]

@gregzaal

BTW BroadStu - would it be possible to add something like the Object Info’s Random output for the hair? So each hair gets assigned a random value. This’d be useful for making slightly inconsistent hair length or transparency fading. Yeah I could just use a dense noise texture, but procedurals have a reputation of being slow.

It would be possible but setting a unique random variable would require extra memory usage. It could be something we add on later as a possible attribute.

[BroadStu]

@theLuthier

I see a lot of exciting test renders happening here!

Finally found the time to play around with Cycles’ strand rendering myself (my apologies for the horrendous video quality). Thank you BroadStu for this brilliant patch! :yes:

Cheers! Fantastic work! I love the edge highlight around the hair. Out of interest how long would a similar render take using BI?

[BroadStu]

Well, I didn’t get around to adding curves over the weekend. Unfortunately, it’s still far too slow in my opinion (50% longer than line segments in some cases). I’m certain that the procedure can be made much faster by using a different curve definition. I will probably add it in its current form soon and work on something else for a bit. Optimizations will come later. I’ve added a few examples below to whet your appetites.

[renderdemon]

@BroadStu

Well, I didn’t get around to adding curves over the weekend. Unfortunately, it’s still far too slow in my opinion (50% longer than line segments in some cases). I’m certain that the procedure can be made much faster by using a different curve definition. I will probably add it in its current form soon and work on something else for a bit. Optimizations will come later. I’ve added a few examples below to whet your appetites.

50 percent slower seems not so bad BroadStu,if the quality is so much better:)
From a memory point of view,how does this work?(there is some gain comparing curves with subdivided line segments?)
Thanks for the hard work

[Ace_Dragon]

This could be seen as a case to add functionality to allow scenes where some particle systems create line segments while others create curves (curves for real complex paths and line segments for everything else).

Heck I could see some good use cases for using systems with basic ribbon/plane primitives in the same scene as systems using the more complex volume-based options.

Keep up the good work, the curves look to give an excellent effect with glass.

[BroadStu]

@renderdemon

50 percent slower seems not so bad BroadStu,if the quality is so much better:)
From a memory point of view,how does this work?(there is some gain comparing curves with subdivided line segments?)
Thanks for the hard work

Yes, I agree. It’s definitely going to be slower than line segments. Line segments will probably be the best method when fast results are required. Curves will probably only be useful when thick strands, glass strands or the best quality renders are required. Memory is one of their other advantages. It transfers the same curve key points and does not use any more memory than line segments. In the examples above the same number of segments were used, with the same memory consumption.

[BroadStu]

@Ace Dragon

This could be seen as a case to add functionality to allow scenes where some particle systems create line segments while others create curves (curves for real complex paths and line segments for everything else).

Heck I could see some good use cases for using systems with basic ribbon/plane primitives in the same scene as systems using the more complex volume-based options.

Adding aspects of this functionality will probably be what I do next. I intend to allow each particle system to choose between the different triangle options or hair segments.

[Andreu]

Here is one more tribble test. I’m starting to get the Hair Info node. I cranked the Steps all the way to 7, but segments are still slightly noticeable. Is there a way of eliminating these gaps? Now I need to find a way to make hair self-colliding so that strands don’t intersect with each other.

[jeff_lamarche]

@theLuthier

please forgive the spaghetti setup :spin:

Kent:

Thanks for sharing. Your videos are awesome, and seeing you translate your hair work into Cycles is exciting.

May I ask one quick question about your shader? There’s one image texture in the mix, upper left and I’m having trouble working out what it does. It gets mixed with the brown ramp using the musgrave before that gets mixed with the gray.

What does that do, and is there any chance you can share anything about the content of that image?

Thanks!

[theLuthier (Kent Trammell)]

@troubled

That’s interesting, I always thought he was just a render of a younger Lloyd Bridges! ><

HAHAHA that’s cracking me up!

Thank you @Farmfield! The strand patch deserves the credit :yes:

[theLuthier (Kent Trammell)]

@BroadStu

Cheers! Fantastic work! I love the edge highlight around the hair. Out of interest how long would a similar render take using BI?

It’s almost not comparable to be honest…But in the past, the best result I’ve achieved for realistic hair in BI is turning off ‘strand render’ and using raytracing. Once I make that decision I can expect up to triple the render times. I think this much hair at this resolution would take between 30-45 min methinks. I’ve never been able to achieve this type of realistic hair using BI shadow maps.

That’s just a guestimation based on similar render setups in the past. But I think I can speak for everyone when I say THANK YOU!

[troubled]

@theLuthier

HAHAHA that’s cracking me up!

hehe Amazing that your model looks that similar actually, even the same hair part! Anyways, couldn’t resist. Great job and take care o/

[troubled]

@Andreu

Here is one more tribble test. I’m starting to get the Hair Info node. I cranked the Steps all the way to 7, but segments are still slightly noticeable. Is there a way of eliminating these gaps? Now I need to find a way to make hair self-colliding so that strands don’t intersect with each other.

Wow, that is very cool looking! I would love to see that animated, all creepy worm like. Agreed though that it would be nice if you could have the hair avoid self collisions with it.