Cycles Strand Rendering

[bat3a]

But saving your setting is creating a userpref.blend

this stuff is from ton, user prefs are now split
see here

[holyenigma74]

i read it, but still dont understand it..

why is it crashing when it tries to read the userpref.blend file upon start?
also what was wrong with the old way.

thanks bat3a for pointing to some information.
i'll mess with it some more..

**edit**

OK!
Figured it out
deleted that blender(unzipped the archive)
tried it again fresh with the new info you gave me..

You need to Ctrl+U first of all to save your startup.blend file..
If you dont and just save your user preferences blender
will crash upload start next time you load it!

So.. if installing as portable.. 2.65/config
Ctrl+U First thing, then go to user preferences then save that.

(to developers, ummm.. if it finds a userprefs.blend but doesn't find a startup.blend it should use the default one(startup.blend) and not crash.., just saving the userpref.blend and quitting blender will not create the startup.blend file although it should if none is present)

think i actually like this way better(just needs a few tweaks)
-----

**edit**
did some testing with CUDA,
nothing to report..
Still painfully slow even on no strand scenes.

[rcpongo]

This is so awesome to have hair in cycles. I've been trying out all my old scenes, and things are looking great.

Here's a Stanford bunny test. (100 passes,... don't mind the banding, that was me not using dithering, plus I tweaked the curves a bit after saving it.)

[manitwo]

woahhh
amazing result rcpongo!
care to share your settings?

[holyenigma74]

here is the Mingw64 Build of the new version
Blender 52955 and Patch verion 52955(isnt that awesome ;D)
I switched to .7z compression its like 16mb smaller for the download for you.
if you need something to unzip it 7-zip.org it free. (or winrar, winzip, etc)

Windows 64Bit
With CUDA(But Use CPU ONLY, CUDA is SLOW on this build right now)
If set as portable(config folder in the 2.65 folder) when Blender Starts
Press Ctrl+U to save your startup.blend first thing you do.
then go to user preferences and set and save those.

Blender_MinGW64_52955_BroadStu_Hairpartch52955_CUD A

http://www.mediafire.com/file/o2fo7x...h52955_CUDA.7z

[0rAngE]

BroadStu, Thanks on this amazing and awesome patch!!! Wow.
holyenigma74, thanks on the win64 builds. I'll try the latest now.

So many cool tests in here! Congrats everyone

Here's my go at it.

[deepee]

quick test done on mac , me likey

[Conz3D]

Currently, it handles child hairs in an identical way to normal hair so I would be very surprised if there's any major difference. Hopefully, at the very end as an extra I hope to add basic child interpolation during rendering. But this will probably be the very last step and may be quite challenging. If it gets that far.

@julperado: Do you set the amount of children with "children -> Display" or with "Children -> Render"?

It looks like the hair is always using the "Display" amount of children. The "Children->render" setting has no effect.

@BroadStu, would it be possible to use the "Children -> Display" amount for the viewport rendering and the "Children -> Rendering" amount for F12 rendering?

[Monster3D]

I use holyenigma74 builds (thanks)
I noticed a significant slowdown with my simple hairy carpet scene.
52833 (old hair patch) : 3:03min
52955 (new hair patch) : 3:54min
Also I notice slightly differences on rendered hairs. The two pictures are not perfectly equals.
But this I assume can be related to the new patch.
Anyone of you notice this slowdonw?
Is it due to new patch, to the build or to some "official" recent blender changes?
PS: Thanks BroadStu for your awesome work.

[peter18]

Here is another test...this time using a hair file sent to me by JeannotLandry a while back...

[Conz3D]

@BroadStu: Could you add the vertexcolors of the mesh to the material? Is this thomething on your side or something for brecht?
I have a teddy with vertexcolors, there I use the VCol in Cycles with an attribute Node.
Here my Nodes for the vertexcolors:
http://www.pasteall.org/pic/41759
As you see, the colors are in cycles. (In the shot I'm in the "vertexpaint" mode.)

But your hair doesn't get the color information. The hair is pure black (now in objectmode):
http://www.pasteall.org/pic/41760

Any ideas? Is it fixable?

[datblender]

Here's my first quick attempt, very fun to play with. My question what causes the rings in the strand. Under certain settings it's worse but this is the best I could get it. At times they looks like big separate cylinders.

[tyrant monkey]

@rcpongo that bunny looks fantastic like manitwo I would also love to see some details of how you did this

[harleynut97]

Is there any recent windows 64 bit builds like what you would download at graphall. I have no idea of how to do all this compiling stuff, I just want to download a build and start playing The only thing I saw on graphicall was for 32 bit windows. I do have a cuda card if that matters.

[McBuff]

Funny how many furballs this thread has and some very good looking and/or creative images done with this.
Very good job!

@spacetug amazing grass you did there, but the turntable makes it look a bit like plastic.

[Monster3D]

Is there any recent windows 64 bit builds like what you would download at graphall. I have no idea of how to do all this compiling stuff, I just want to download a build and start playing The only thing I saw on graphicall was for 32 bit windows. I do have a cuda card if that matters.

Look at post #305

[BroadStu]

@Monster3D, Ahh that's unfortunate. It's completely due to the new patch. I changed the intersection test. Before it included some code to quickly test if it doesn't hit. One of these was responsible for the strange artifacts. I decided to disable them both as I hoped the main intersection routine would be quick enough and thought these could just be slowing it down. It's also why the strands appear slightly different. They will appear a tiny bit thicker in the later patch. I will see about putting the test back in for future patches and possibly just put a user option to activate them or not.

@Conz3D - Yes, it only uses the display number at the moment. I never considered this an important restriction so decided to leave it until later to fix. I will see if I can fix it easily. As for vertex colours, the patch currently doesn't support any attributes. I added the uvs as a temporary solution. It can definitely be fixed though but not quickly.

@datblender - Very nice results. The bands are because it does render the line segments as cylindrical sections. For thick strands with a large curvature gaps and crossovers occur. This would be one advantage of triangle geometry, although you couldn't get the transition now. Once curve segments are implemented the bands won't be an issue.

I am actually torn between starting to work on one of these issues. Attributes or curve segments?

[Conz3D]

Thank you for the answer.
If you ask me ... next issue to work on: the attributes.

[aermartin]

@datblender nice. that looks almost like small saplings, animate the length/growth and it could totally be like vegetation on Na'vis homeplanet looks really promising. I hope it ends up in trunk sooner than later.

[TheEmptyRoom]

I am actually torn between starting to work on one of these issues. Attributes or curve segments?

@BroadStu Curved segments is by far more important IMO. Wouldn't this mean way better memory usage as you won't need such high resolution segments when building the BVH. Get the foundation solid and then start adding the features. This will also improve the look of the hair.

I love the work you are doing Stu. It works remarkably well already.

There does seem to be some slight anti aliasing issues due to very fine strands. An ever so slight stair stepping. I presume this is just Cycles's sampling due to the very fine filaments. Anybody have any suggestions?