Hi!

I'm trying to make a creaturewith fur and I'm looking for good ways to render it in big resolution as a animation.
I want to achive good affect and I want that It would be pretty fast (not very fast, but fast enough to render animation not in infinity time (on small renderfarm).

I saw that I could use normal mantra witharea lights, but then shadows on fur are not to beautifull (the whole shading is strange - definitely it needs something like gi).

The problem is that when I turno on gi (I create light template with light shader set to VEX Global Illumination shader) and I use any type of irradiance, the render time increasesvery much!
I've tried render it with photons (mikropolygon), but it is slow and I didn't get good results.
Only PBR render give some really good looking fur, but I'm aware that it could be slow when rendering animation?

Please If you have any “relationships” with rendering fur in Houdini for animation, share some best techniques - what render to use (mikropolyugon, pbr, ..?) etc

Thank you very much!

Good question, any information about rendering fur efficiently would be nice.

Sorry the bad english.

I've gotten some excellent results from houdini using the micropolygon renderer at HD. Full screen characters (squirrels) with motion blur rendering around 40 minutes a frame. I don't use anything but distant lights with depth map shadows (with transparency). An environment light for a base color (if you have HDR) can be used for ambiance too.

A good hack is to use the ambient occlusion sop with your skin (floating around in the exchange) and use the resulting attribute in the hair shader to transfer the AO shadowing to the hair color.

Also, for motion blur we've been getting away with geometry velocity blur.

Cześć Wojtku,

efficient fur rendering is kind of the holy grail in computer graphics. Do not expect easy answers or magic solutions. People working with fur wait for their knowledge for years, and as they say, every new job is a kind of adventure. There are a couple of proprietary pipelines ready to deliver high quality fur creatures, but this is rare cases (R+H, Weta, Pixar).

Nevertheless Houdini's fur tools bring a lot of the power to your disposal, you just need lots of testing and understanding of fur pipeline.

First, fur/light interaction is handled mostly by a good fur shader. Dig around for some good papers on this subject, and try to implement any of those. I can guarantee you that 90% or a good looking fur can be achieved without a single ray. Ray tracing a fur (even ray traced shadows) is pretty advance topic, you can go a long route without that, believe me. After that, you could check out Siggraph papers on baking global illumination for fur shading. Naive GI on a fur is no way to go… you don't want that. I seriously don't think that a fur has been ever raytraced in any of good fur shots in a movies…

Go with shadow maps, fine tuned hand crafted lights, good shading model ( light scattering/ backface scattering etc), bake some illumination (like AO) into a couple of textures used by hair vertices. Make lots of tests.

…or something similar

Thanks for the answers it really helps.

I notice even on a early start that GI with fur is a no way to go, very slow even for quick tests, shadow maps they really work great, but a occlusion is a must I think.

I didn't work with this occlusion asset but maybe is a way to achieve this.

Any more tips would be appreciated.

Woow thank you Symek and pinkwerks!

Symek you've said so many inspiring informations! Thank you very much!
I cannot wait to try to make it Please could you tell me if you're talking about shaderslike this one: “Light Scattering from Human Hair Fibers” (2002 Siggraph), that weta was using to render king kong (https://renderman.pixar.com/products/whats_renderman/showcase_kingkong.html) [renderman.pixar.com] or you know better than this one?

SYmek
Go with shadow maps, …

Deep shadow maps at that.

danilo2
Woow thank you Symek and pinkwerks!

Symek you've said so many inspiring informations! Thank you very much!
I cannot wait to try to make it Please could you tell me if you're talking about shaderslike this one: “Light Scattering from Human Hair Fibers” (2002 Siggraph), that weta was using to render king kong (https://renderman.pixar.com/products/whats_renderman/showcase_kingkong.html) [renderman.pixar.com] or you know better than this one?

Here is a cool site if you are looking for papers.
http://kesen.realtimerendering.com/ [kesen.realtimerendering.com]

mawi! woow that's really goood
thanks!