www.si-community.com
http://www.si-community.com/community/

Kristinka Hair Tests
http://www.si-community.com/community/viewtopic.php?f=24&t=447
Page 4 of 10

Author:  druitre [ 20 Mar 2010, 16:27 ]
Post subject:  Re: Kristinka Hair Tests

Quote:
Btw: I just read on the Softimage mailing list, the pixel size unit thing was changed in 2011.


What will (all of) the consequences of that change be? From this thread I understand at the moment there's a problem when rendering animations with K-hair (the hair thickness doesn't stay constant relative to world space), right? Is it a MR issue or something else?

Author:  Mathaeus [ 20 Mar 2010, 16:39 ]
Post subject:  Re: Kristinka Hair Tests

It's Softimage issue, that can be fixed by adding a few nodes. Consequence is that hairs looks thinner with camera zoom and reverse, also, render region and final render can look different...

For animations, without some wild camera movements, I found the current option a bit better, to be honest. Seems to be much easier to get correct anti aliasing...

Author:  druitre [ 20 Mar 2010, 17:03 ]
Post subject:  Re: Kristinka Hair Tests

Hi Mathaeus,

sorry, I don't understand your answer. Do you say that after 'adding a few nodes', the hair won't 'look thinner with camera zoom'?

And when you say 'I found the current option a bit better', do you mean not using those 'few nodes' is better than using them or do you mean the difference between 2010 and 2011?

Also, with 'camera zoom', do you mean lens angle or camera distance?

I think a better way to put my initial question would be: what is that pixel size unit issue, what's it about and what problems will be gone with the fix?

thanks, Jasper

Author:  Mathaeus [ 20 Mar 2010, 19:28 ]
Post subject:  Re: Kristinka Hair Tests

druitre wrote:
Hi Mathaeus,
I think a better way to put my initial question would be: what is that pixel size unit issue, what's it about and what problems will be gone with the fix?
thanks, Jasper


Actually, I would call that 'choice', more than 'issue'. Rendering a lot of thin, overlapping objects, that's always a challenge. Regardless of world or screen space, you'll have to 'do something' with, for example, thin grass which is far away from camera, that constantly 'buzzing' from frame to frame. At this stage, current, screen space, seems to be easier to control.

It's not big deal to create compound that changes strand size according to output resolution, distance to camera and camera angle, but this one can kill the playback. Also you still won't get it right in render region, unless you manually enter a some 'estimate' values.

Anyway, I'll try to create compound.

Author:  Mathaeus [ 20 Mar 2010, 20:56 ]
Post subject:  Re: Kristinka Hair Tests

Hi,

I think that is the formula in ICE language. "1024" is screen resolution (I think it's horizontal resolution), "0.1" is strand thickness in SI units. Probably it's good idea to ad "clamp" node at the end, for keeping strand size in desired screen units. This one uses point position ("strand root"). For more accurate, but slower calculation, strand position may be used instead.

Cheers

screen shot of ICE tree

Author:  Ahmidou [ 21 Mar 2010, 12:19 ]
Post subject:  Re: Kristinka Hair Tests

Actually, the pixel size unit limitation was not changed in 2011 but you'll now have the choice between screen space and world space size.

Hey Mathaeus I found some lecture for you :D
http://www.disneyanimation.com/library/detailPreservingContiniumHair.pdf

Author:  Mathaeus [ 21 Mar 2010, 13:47 ]
Post subject:  Re: Kristinka Hair Tests

Thank you for link, even I already have a whole bag of these :) I got them from my fellows, game programmers... At this time, I have no plans for simulation improvements - all work is still focused on styling, including styling in ICE post-simulation.

Author:  Mathaeus [ 03 Apr 2010, 23:23 ]
Post subject:  Re: Kristinka Hair Tests

Hi all

here are a few new ones. Styling is the same as in 'Follow-NURBS-Offset-Curves' demo in the lastest release, but with a bit different layout of NURBS surfaces.

Actually images are rendering tests, how MR is handling with all that, rendered in one go. It's rasterizer with final gathering, also raytraced reflections at some places. Finally I was able to get these renderings finished, only by playing with 'max depth' parameter in rasterizer's settings - it's a some kind of 'trace level' for rasterizer, that can dramatically speed-up the rendering, but also leaves the areas with black alpha.

Image

Here is screenshot of ICE trees. - a big one.


Cheers

Author:  Mathaeus [ 03 Apr 2010, 23:25 ]
Post subject:  Re: Kristinka Hair Tests

... and another one

Image

Author:  Rork [ 09 Apr 2010, 10:45 ]
Post subject:  Re: Kristinka Hair Tests

Impressive work, as always :-bd ^:)^ ^:)^

Page 4 of 10 All times are UTC + 1 hour [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/