cglandlogo First Page
°í°´¼¾ÅÍ   
gallery media job community contentsmall  
  dbrush Blizzardfest 2014

Warning: main(/data/cgland/public_html/r06inc/gnb_edu.html) [function.main]: failed to open stream: No such file or directory in /data/cgland/public_html/r06inc/top_menu_common.html on line 91

Warning: main(/data/cgland/public_html/r06inc/gnb_edu.html) [function.main]: failed to open stream: No such file or directory in /data/cgland/public_html/r06inc/top_menu_common.html on line 91

Warning: main() [function.include]: Failed opening '/data/cgland/public_html/r06inc/gnb_edu.html' for inclusion (include_path='.:/usr/local/php/lib/php') in /data/cgland/public_html/r06inc/top_menu_common.html on line 91
  ȸ¿ø ȸ¿ø»ç º¸¾ÈÁ¢¼Ó
 
IDÀúÀå
  °³ÀÎȸ¿ø°¡ÀÔ ¤Ó ±â¾÷ȸ¿ø°¡ÀÔ
  ¾ÆÀ̵ð l ºñ¹Ð¹øÈ£ ã±â
ÀÔ»çÁö¿øÇÒ¶§ ÆÄÆ®¸¦ µÎ°¡..
¸¶¾ß¿¡¼­ ¸·´ë ±×·¡ÇÁ¸¦
°ÇÃàµðÀÚÀÎÂÊ Áø·Î¸¦ »ý°¢..
¿µ»ó°ü·ÃÇؼ­ ¹è¿öº¸°í½Í..
½Ã³×¸¶Æ÷µð¸¦ ¹è¿ì°í½Í½À..
Mental Ray¸¦ ÀÌ¿ëÇÑ 3SÀÇ ½Çü view : 3340 | Ãßõ : 0 | 2007-04-01
3D | Maya Ãâó : À̼ºÂù


Mental Ray¸¦ ÀÌ¿ëÇÑ 3SÀÇ ½Çü
3S = Sub Surface Scattering

±Û. À̼ºÂù
Nthma Production Team
Render Part TD
Nthma Production Team (http://www.nthma.com)


MayaÀÇ Mental Ray¸¦ ÀÌ¿ëÇÑ Sub Surface Scattering(ÀÌÇÏ 3S) ±â¹ý¿¡ ´ëÇؼ­ ¾Ë¾Æ º¸ÀÚ.

Sub Surface ScatteringÀº BSSRDF¿¡ ±â¹ÝÇÑ ¹ÝÅõ¸í ÀçÁú¿¡ ´ëÇÑ »ç½ÇÀûÀÎ ½Ã¹Ä·¹À̼ÇÀ» À§ÇÑ ·»´õ¸µ ±â¹ýÀÌ´Ù. ÇǺÎ, »À, ½Ä¹°ÀçÁú°ú °°Àº organic¿¡ ¶ÇÇÑ ¾óÀ½°ú ¸¶ºí°ú °°Àº ¶óÀÌÆ®¿¡ ÀÇÇÑ »ê¶õÀÌ ÀϾî¶ó´Â ÀçÁú¿¡ ´ëÇؼ­ µµ Àû¿ëÇÒ¼ö ÀÖ´Â ¹æ½ÄÀÌ´Ù.

±×·¸´Ù¸é BSSRDF / BRDF¶õ ¹«¾ùÀΰ¡?
(Bidirectional Surface Scattering Distribution Function) / (Bidirectional Reflectnace Distribution Function)


BRDF ±â¹ý


BSSRDF ±â¹ý

À§ÀÇ µÎ À̹ÌÁö´Â ÀϹÝÀûÀÎ BRDF¿Í BSSRDF ÀÇ »ý¼º¿ø¸®¸¦ º¸¿© ÁÖ´Â ±×¸²ÀÌ´Ù.
±×¸²¿¡¼­µµ ¾Ë¼ö ÀÖµíÀÌ ÀϹÝÀûÀÎ BRDF´Â Ç¥¸éÀÇ Èí¼öµÇ´Â ºûÀÌ ¾øÀ½À» ¾Ë¼ö ÀÖ´Ù. ÇÏÁö¸¸ BSSRDF´Â Ç¥¸éÀÇ ¹Ý»ç »Ó ¾Æ´Ï¶ó Ç¥¸é¾Æ·¡¿¡¼­ÀÇ Èí¼ö ¹× »ê¶õ±îÁö °¡´ÉÇÏ°Ô ÇÑ´Ù.

[ÂüÁ¶] Henrik Wann Jensen, Stephen R. Marschner, Marc Levoy and Pat Hanrahan : Siggraph 2001

Àá½Ã Sub Surface Scattering(ÀÌÇÏ 3S)ÀÇ Âü°íÀ̹ÌÁöµéÀ» º¸ÀÚ.


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.


[ÂüÁ¶] Lightengin3D Gallery Subsurface Scattering / µ¿¿µ»ó º¸±â


ÀÌÁ¦ º»°ÝÀûÀ¸·Î Mental RayÀÇ »ç½ÇÀûÀÎ 3S ±¸Çö¹æ¹ý¿¡ ´ëÇؼ­ »ìÆ캸±â·Î ÇÏÀÚ.



ÀÌÁ¦ BSSRDF¸¦ Á÷Á¢ ½Ã¹Ä·¹ÀÌ¼Ç ÇÒ¼ö ÀÖ´Â ½¦ÀÌ´õÀÎ misss_physical shader¸¦ ¼³Ä¡ ÇÏ°í Á¢±ÙÇØ º¸ÀÚ

Intro
Requirement
- Mental Ray 3.3 ÀÌ»ó
- miss_physical shader
- Alias Maya 6.0 ÀÌ»ó (mentalray 3.3.1 Æ÷ÇÔ)

misss_physical shader¸¦ maya¿¡ ¼³Ä¡ÇÑ´Ù.


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.

- subsurface.miÀ» ¾Æ·¡ÀÇ Æú´õ¿¡ ³Ö¾îµÐ´Ù. ÆÄÀÏÀº misss_physical shader ¾ÐÃàÆÄ ÀÏ ¾È¿¡ Á¸ÀçÇÑ´Ù. (/mentalray/include)

- put subsurface.{DSO}À» ¾Æ·¡ÀÇ Æú´õ¿¡ ³Ö¾îµÐ´Ù.
(/mentalray/lib)

- /mentalray/maya.rayrc ¹®¼­¸¦ ¿­°í À§ À̹ÌÁö¿Í °° ÀÌ Ãß°¡ÆíÁýÇÑ´Ù.

- mel script¸¦ Æú´õ¿¡ º¹»çÇÑ´Ù. /scripts/AETemplates

- ¾ÆÀÌÄÜÀ» Æú´õ¿¡ º¹»çÇÑ´Ù. /icons

- È®ÀÎ maya hypershader mentalray node tab - misss_physical_shader
(mentalray render node¿¡ µé¾î¿ÍÀÖ´ÂÁö)

Scene Database¿Í Shader Assignment
ÀÌÁ¦ 3S¿¡ ´ëÇØ ¾Ë¾Æº¸±â À§ÇØ »ùÇà Àå¸é°ú ÀçÁú»óŸ¦ È®ÀÎÇغ¸ÀÚ.


Milk SceneÀÇ Àå¸é ±¸¼º

- ¿ìÀ¯ÄÅ : ´ÝÈù Nurbs Surface
- ¿ìÀ¯ : ¿ìÀ¯ÄÅ º¸´Ù Á¶±Ý ÀÛ°Ô ¸¸µé¾îÁø ÇüÅ / À­ºÎºÐ°ú ¿ìÀ¯¸öÅë ºÎºÐ ºÐ¸® - ´ÝÈù Nurbs Surface
- »¡´ë : ´ÝÈù Nurbs Surface
- Æú¸®°ïÀ¸·Î ±¸¼ºµÈ CornellBox
- Focal length 110mm Ä«¸Þ¶ó
- ÁÖÁ¶¸íÀÎ point light(ÄÚ³Ú»óÀÚÀÇ »ó´Ü¿¡ À§Ä¡)

Shader Assignment
- ¿ìÀ¯ÄÅ : dielectric_material °ú dielectric_material_photon shader
- ¿ì À¯ : misss_physical material °ú photn shader
- »¡ ´ë : dgs_material °ú dgs_material_photon shader
- ÄÚ³Ú»óÀÚ : dgs_material °ú dgs_material_photon shader
- Æ÷ÀÎÆ®¶óÀÌÆ® : mib_physical_light
(250000 caustics photon / 250000 GI photon / photon intensity 3500)

non-tweaked SSS
¿ìÀ¯ ÀçÁúÀ» ÇÒ´çÇϱâ À§ÇØ misss_physical shader¸¦ ¾Æ·¡¿Í °°ÀÌ Àû¿ëÇÏ°í ÀüüÀå ¸éÀ» À§ÇÑ GI ¼ÂÆÃÀ» Çغ¸ÀÚ.

misss_physical shader¸¦ material °ú photon¿¡ Àû¿ë


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.

- ¿ì¼± GI¿Í Caustics¸¦ À§ÇÑ ±âº»¼ÂÆÃÀ» Çغ¸ÀÚ

Caustics
- Caustics On
- Caustics Accuracy 1000, Radius 1, Filter Type : Box, Filter Kernel : 1.1

Global Illumination
- GI On
- Global Accuracy 1000, Radius 8


misss_physical shader¸¦ À§ÇÑ ±âº»¼ÂÆÃ

Optical Properties
Material : 0.5, 0.5, 0.5 (RGB)
Transmission : 0.5, 0.5, 0.5 (RGB)
Index of refraction : 1.3
Absorption coeff : 0.001, 0.002, 0.014
Scattering coeff : 0.7, 1.220, 1.900
Scale conversion : 10.000
Scattering anisotrophy : 0.750


Algorithm control
Depth : 10.000
Max Samples : 1
Max Photons : 10
Max Radius : 10.000
Approx diffusion/ single, multi scattering : on


- ·»´õ¸µµÈ À̹ÌÁö ÀÌ´Ù.

: À§¿Í °°ÀÌ ¿ìÀ¯ÀÇ ³»ºÎ¿¡ Æ÷ÅæÀÌ ³ì¾Æµé¾î°¡ ÀÖ´Â ¸ð½ÀÀ» º¼¼ö ÀÖ´Ù.
: À§ÀÇ ¼³Á¤Àº ±âº»ÀûÀ¸·Î Æ÷ÅæÀÌ ¿ìÀ¯ ¾È¿¡¼­ÀÇ »ê¶õ °úÁ¤À» À§ÇÑ °£´ÜÇÑ Å×½ºÆ® À̹ÌÁö ÀÌ´Ù.

- À§ÀÇ ÆĶó¹ÌÅÍ¿¡¼­ Á¦ÀÏ Áß¿äÇÑ ¿É¼ÇÀº scale_conversion ÀÌ´Ù. ÀÌ°ÍÀº »ê¶õ (scattering)ÀÇ ±æÀ̸¦ ÃøÁ¤Çϱâ À§ÇÑ °ÍÀ¸·Î Á¤È®ÇÏ°Ô »ç¿ëÇØ¾ß ÇÑ´Ù.

- scattering °ú absorption coefficients(°è¼ö)´Â ÀϹÝÀûÀ¸·Î ¸¹Àº ¹°Áú¿¡¼­ »ç¿ë µÇ´Â °ªÀ» Àû¿ëÇÑ´Ù.
¿©±â¼­ °è¼ö´Â inverse milimeter ÀÇ unitÀÌ´Ù.

- max radius ´Â unit°ú À¯»çÇÑ °ªÀ» °¡Á®¾ß ÇÑ´Ù. ¸¸¾à Àå¸éÀÌ centimeter ´ÜÀ§·Î µÇ¾î ÀÖ´Ù¸é 1/10·Î ÁÙ¿©¾ßÇÑ´Ù.

- scattering coefficient¸¦ À§ÇÑ unitÀ» Us ·Î absorption coefficient¸¦ À§ÇÑ unitÀ» Ua ·Î Çϸé coefficientÀÇ °ª°ú Æ÷ÅæÀÌ ÀçÁúÀ» Åë°úÇØ °£¼·ÀÌ ¾ø´Ù°í °¡Á¤ÇÏ ´Â °Å¸® LÀº ´ÙÀ½°ú °°ÀÌ Á¤ÀÇ µÈ´Ù. absorption°ú scatteringÀÇ Æ÷ÅæÀÌ Àü´Þ µÉ È® ·ü P´Â

P=exp (-(Ua +Us)L)

- ÇöÀçÀÇ ¿ìÀ¯¿¡ ´ëÇÑ °ÍÀº Á÷Áø¿¡ ´ëÇÑ scattering ÀçÁúÀ̹ǷΠscattering_anisotropicÀº ¿ì¸®°¡ ½ÃÀÛÁ¡À¸·ÎºÎÅÍ depth, max_photon, max_sample, max_radius¿¡ ´ëÇØ ³·Àº °ªÀ» »ç¿ëÇϹǷΠ0.75ÀÇ °ª Á¤µµ·Î Àû¿ëÇÑ´Ù.


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.



Photon Scattering


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.

: À§ÀÇ ¿ÞÂÊ À̹ÌÁö´Â ±âº»¼ÂÆÿ¡¼­ ½¦ÀÌ´õÀÇ max_radius¸¦ 1·Î ¹Ù²Û À̹ÌÁöÀÌ ´Ù.
: À§ÀÇ ¿À¸¥ÂÊ À̹ÌÁö´Â map visualizer¸¦ ÀÌ¿ëÇØ causticsÀÇ Æ÷Åæ ºÐÆ÷¸¦ ½Ã°¢ÀûÀ¸ ·Î º¸¿©ÁÖ´Â À̹ÌÁöÀÌ´Ù.

Increase Photons


Caustic Photons = 100000
Global Photons = 100000

: ÀÌÁ¦ Æ÷ÅæÀÇ ¼ö´Â ÃæºÐÇÑ °ÍÀ¸·Î º¸ÀδÙ. ÀÌÁ¦ ¿ì¸®°¡ °ü½ÉÀ» µÎ¾î¾ß ÇÒ ºÎºÐÀº Æ÷ÅæÀÇ Æò±ÕÀÌ´Ù. Áï max_photon °ú max_radiusÀÇ Å©±â¸¦ Á¤ÇØÁÖ´Â °ÍÀÌ´Ù. max_photonÀº ÁÖ¾îÁø max_radius¿¡¼­ ÃÖ´ë ¾ó¸¶ÀÇ photonÀ» ãÀ»°ÍÀΰ¡¿¡ ´ëÇÑ ¿É¼Ç ÀÌ´Ù.


Photons Average


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.

: À§ÀÇ À̹ÌÁö´Â max_photonÀ» 1000À¸·Î, max_radius¸¦ 2·Î Áõ°¡½ÃŲ À̹ÌÁöÀÌ ´Ù.
: output À©µµ¿ì¸¦ ÅëÇؼ­ º¸¸é ¿ì¸®°¡ ¿øÇÑ 1000°³ÀÇ Æ÷ÅæÀ» ¸ðÀ¸Áö ¸øÇß´Ù. ÀÌ°Í Àº 7°³ÀÇ Æ÷Å游ÀÌ »ùÇà ¿¬»ê¿¡ »ç¿ëµÇ¾î Á³À½À» ÀǹÌÇÏ°í ÀÖ´Ù.
max_radius °ªÀ» Áõ°¡½ÃÄÑ Ãß°¡ÀûÀÎ »ùÇà ¿¬»êÀ» ½ÃÄѺ¸ÀÚ.


±×¸²À» ´©¸£½Ã¸é Å©°Ô º¸½Ç ¼ö ÀÖ½À´Ï´Ù.

: À§ÀÇ À̹ÌÁö´Â max_radius¸¦ 40À¸·Î ¿Ã¸° À̹ÌÁöÀÌ´Ù. mean¿¡¼­ ÀǹÌÇÏ´Â Æ÷Åæ 1000°³¸¦ ¸ðÀ¸´Âµ¥ ¼º°øÇÏ¿´´Ù.
: À§¿Í °°ÀÌ max_raius¸¦ °ªÀ» À¯»çÇÏ°Ô Ã£´Â °ÍÀÌ Áß¿äÇÏ´Ù°í º¼¼ö ÀÖ´Ù.
: ÀÌ°ÍÀº ¸ðµ¨¸µÀÇ unitÀÇ Å©±â°¡ ¸Å¿ì Áß¿äÇÔÀ» ÀǹÌÇÏ´Â °ÍÀ̱⵵ ÇÏ´Ù




control brightness
: ¿ì¸®´Â output À©µµ¿ìÀÇ Á¤º¸¸¦ ÅëÇØ ½¦ÀÌ´õÀÇ ¿¡³ÊÁö ±ÕÇüÀ» Á¶ÀýÇÏ°Ô µÈ´Ù. ±× ·¯³ª Ç×»ó ¿øÇÏ´Â ¹à±â·Î µÇ´Â °ÍÀÌ ¾Æ´Ï±â ¶§¹®¿¡ ÀÌ ºÎºÐÀ» ´Ù½ÃÇѹø ¼³Á¤ÇØ ÁÖ¾î ¾ß ÇÑ´Ù.
: material °ú transmission color ¶Ç´Â lightÀÇ Æ÷Åæ ¿¡³ÊÁö¸¦ Á¶ÀÛÇϹǷνá ÀÏ¹Ý ÀûÀ¸·Î ¹à±â¸¦ ¼³Á¤ÇÒ ¼ö ÀÖ´Ù.

1. misss_physicalÀÇ material¿¡ °ªÀ» Ãß°¡½ÃÅ°´Â ¹æ¹ýÀÌ ÀÖ´Ù.
2. scatteringÀÇ ¿µÇâÀ» ´ú ¹Þ±â À§ÇØ transmissionÀÇ »ç¿ëÀ» ³·Ãß´Â ¹æ¹ýÀÌ ÀÖ ´Ù.

À§ÀÇ À̹ÌÁö´Â transmission - 0.25, 0.25, 0.25¸¦ Àû¿ë, Æ÷ÅæÀÇ À̵¿°Å¸®°¡ ±×¸¸ Å­ ¾àÇØÁ³´Ù.


Final Quality and better visualize caustics

Final Image

Optical Properties
Material : 0.5, 0.5, 0.5 (RGB)
Transmission : 0.2, 0.2, 0.2 (RGB)
Index of refraction : 1.3
Absorption coeff : 0.0014, 0.0025, 0.0142
Scattering coeff : 0.7, 1.220, 1.900
Scale conversion : 10.000
Scattering anisotrophy : 0.750

Algorithm control
Depth : 10.000
Max Samples : 10
Max Photons : 4000
Max Radius : 50.000
Approx diffusion/ single, multi scattering : on
Caustic Photon : 250000
Global Photon : 250000


´Ù¾çÇÑ 3S¿¡ ´ëÇÑ Á¢±Ù ¹× °á·Ð
´Ù¾çÇÑ 3S¸¦ ±¸ÇöÇÒ¼ö ÀÖ´Â ½¦ÀÌ´õµé


Lightengin3dÀÇ SubscatteringÀ» ±¸ÇöÇϱâ À§ÇÑ ½¦ÀÌ´õ.


Wang WeiÀÇ Bssrdf ½¦ÀÌ´õ¸¦ ÀÌ¿ëÇÑ SubscatteringÀÇ ±¸ÇöÇϱâ À§ÇÑ Attribute



¼Ò½ºÆÄÀÏ ´Ù¿î¹Þ±â >>

°á ·Ð
: 3S´Â ¿ì¸® ÁÖÀÇ¿¡¼­ ÈçÈ÷ º¼¼ö ÀÖ´Â (½ÉÁö¾î ¿ì¸®ÀÇ ÇǺÎÁ¶Â÷µµ) Çö»óÀ» ±¸ÇöÇϱâ À§ÇÑ ½Ã¹Ä·¹À̼ÇÀÌ´Ù.
¿©·¯ °¡Áö ¹æ¹ýÀÌ ÀÖÁö¸¸ À̹ø¿¡ ¼Ò°³ÇÑ ³»¿ëÀº mentalrayÀÇ 3S¸¦ ÀÌ¿ëÇÏ¿© ¹°¸®ÇÐ Àû ½Ã¹Ä·¹À̼ÇÀ» ÀÌ¿ëÇÑ ¹æ¹ýÀÌ´Ù. ÇǺΠ»Ó¸¸ ¾Æ´Ï¶ó ¾Õ¼­ ¼Ò°³ÇÑ ¿©·¯ À̹ÌÁö¿¡¼­ µµ º¼¼ö ÀÖµíÀÌ ¿©·¯ Çö»óµéÀ» »ç½Ç°¨ÀÖ°Ô Ç¥ÇöÇÒ ¼ö ÀÖ´Ù.

Á¢±Ù ¹æ½Ä¸¸ ´Ù¸¦ »Ó À§ÀÇ ´Ù¸¥ ½¦ÀÌ´õµéÀ» ÀÌ¿ëÇÏ¿©µµ À¯»çÇÑ ´À³¦À» ±¸ÇöÇÒ ¼ö ÀÖ ´Ù.

»ç½ÇÀûÀÎ photorealisticÇÑ À̹ÌÁö¸¦ ±¸ÇöÇÏ´Â ³ë·ÂÀº °è¼Ó µÇ¾îÁö´Â µí ÇÏ´Ù. Áö±Ý µµ.....


³ëÆ® : Subscattering¿¡ ´ëÇÑ ºÐ¼®Àº Alias maya 6.0 bonus toolÀÇ ³»¿ë¿¡ ´ëÇÑ °ÍÀÓÀ» ¹àÇô µÐ´Ù.



±Û. À̼ºÂù
Nthma Production Team
Render Part TD
Nthma Production Team (http://www.nthma.com)







| 1 |