mental ray Architectural and Design Visualization Shader Library

More documents

Recommendations

Info

66 3 Sun and Skya bounding box in the coordinate system of the light within which photons are aimed.This can be used to “focus” GI photons on a particular area-of-interest. For example, ifone has modelled a huge city as a backdrop, but is only rendering the interior of a room,mental ray will by default shoot photons over the entire city and maybe only a few willfind their way into the room. With the photon bbox max and photon bbox minparameters one can focus the photon emission of the mia physicalsunto only aim atthe window in question, greatly speeding up and enhancing the quality of the interiorrendering.• automatic photon energy enables automatic photon energy calculation. When thisis on, the light source does not need to have a valid energy value that matches that ofthe sun (it does, however, need a nonzero energy value or photon emission is disabledby mental ray). The correct energy and color of the photons will be automaticallycalculated. If this parameter is off, the photons will have the energy defined by thelights energy value.• If illuminance mode is zero, the default solar intensity used (calculated internallybased on the haze, solar angle, optical airmass, etc.) which is compatible with previousversions of the library. If illuminance mode is 1, the sun light will have the directnormal illuminance (in lux) set by the direct normal illuminance parameter. Thecolor of the sunlight is still driven by the haze as before, only the intensity is modified.3.6 Sky ParametersThe mia physicalsky shader is responsible for creating the color gradient that represent theatmospheric skydome, which is then used to light the scene with the help of Final Gatheringand/or sky portals (page 71). The mia physicalsky, when used as an environment shader, alsoshow the sky to the camera and in reflections.mia physicalsky also creates a virtual ground plane that exists “below” the model. This makesit unnecessary to actually model geometry all the way to the horizon line - the virtual groundplane provides both the visuals and the bounce-light from such ground.declare shader "mia_physicalsky" (boolean "on"default on,scalar "multiplier" default 1.0,color "rgb_unit_conversion" default 0.0001 0.0001 0.0001,scalar "haze" default 0.0,scalar "redblueshift" default 0.0,scalar "saturation" default 1.0,scalar "horizon_height" default 0.0,scalar "horizon_blur" default 0.1,color "ground_color" default 0.2 0.2 0.2,color "night_color" default 0 0 0,vector"sun_direction",
3.6 Sky Parameters 67light"sun",# The following parameters are only useful# when the shader is used as environmentscalar "sun_disk_intensity" default 1.0,scalar "sun_disk_scale" default 4.0,scalar "sun_glow_intensity" default 1.0,boolean "use_background",shader "background",# For the lens/volume shader modescalar "visibility_distance",boolean "y_is_up",integer "flags",integer "sky_luminance_mode" default 0,scalar "zenith_luminance" default 0.0,scalar "diffuse_horizontal_illuminance" default 0.0,# Perez model luminance distribution parametersscalar "a",scalar "b",scalar "c",scalar "d",scalar "e",)boolean "physically_scaled_sun"version 5apply environment, texture, lens, volumeend declare• on turns the shader on or off. The default is on.• multiplier is a scalar multiplier for the light output. The default is 1.0.• rgb unit conversion allows setting the units, described in more detail above. Thespecial value of 0 0 0 matches 80000 lux (light level on a sunny day) to the output value1, suitable for low dynamic range rendering.• horizon height sets the “level” of the horizon. The default value of 0.0 puts the horizonat standard “height”. But since the horizon is infinitely far away this can cause troublejoining up with any finite geometry that is supposed to represent the ground. It can alsocause issues rendering locations that are supposed to be at a high altitude, like mountaintops or the top of New York skyscrapers where the horizon really is visibly “below” theviewer.This parameter allows tuning the position of the horizon. Note that the horizon doesn’tactually exist at any specific “height” in 3D space - it is a shading effect for rays that
Page 1 and 2:
mental ray Architectural and Design
Page 3 and 4:
Table of Contents1 Introduction 11.
Page 5:
Table of Contentsix3.8.3 Examples .
Page 9 and 10:
Chapter 2Architectural Material2.1
Page 11 and 12:
2.2 Fundamentals 52.2.1.1 A Note on
Page 13 and 14:
2.3 Features 7Hence, when using GI:
Page 15 and 16:
2.3 Features 9The rules are as foll
Page 17 and 18:
2.3 Features 11In the real world
Page 19 and 20:
2.3 Features 13Used alone, an AO sh
Page 21 and 22: 2.3 Features 152.3.7 Performance Fe
Page 23 and 24: 2.4 Quick Guide to the Material Par
Page 25 and 26: 2.5 Detailed Description of Materia
Page 55 and 56: 2.6 Tips and Tricks 49• For extre
Page 57 and 58: 2.6 Tips and Tricks 51Diagram for g
Page 59 and 60: 2.6 Tips and Tricks 53There is one
Page 61 and 62: 2.6 Tips and Tricks 55• Glass-Liq
Page 63 and 64: 2.6 Tips and Tricks 57Enjoy the tro
Page 65 and 66: 2.6 Tips and Tricks 59Many small ad
Page 67 and 68: Chapter 3Sun and Sky3.1 Introductio
Page 69 and 70: 3.4 Common Parameters 633.3 Importa
Page 71: 3.5 Sun Parameters 65• saturation
Page 75 and 76: 3.6 Sky Parameters 69• sun direct
Page 77 and 78: 3.8 Sky- and Environment Portals 71
Page 89 and 90: 3.9 Photometric Lights 833.9 Photom
Page 91: 3.9 Photometric Lights 85• When i
Page 94 and 95: 88 4 Camera- and Exposure EffectsAl
Page 96 and 97: 90 4 Camera- and Exposure Effects4.
Page 98 and 99: 92 4 Camera- and Exposure Effects1,
Page 100 and 101: 94 4 Camera- and Exposure EffectsTh
Page 102 and 103: 96 4 Camera- and Exposure Effectscr
Page 104 and 105: 98 4 Camera- and Exposure EffectsEv
Page 106 and 107: 100 4 Camera- and Exposure EffectsS
Page 109 and 110: Chapter 5General Utility Shaders5.1
Page 111 and 112: 5.2 Environment Blur 105replaced by
Page 113 and 114: 5.2 Environment Blur 107But what is
Page 115 and 116: 5.2 Environment Blur 109Glossiness
Page 117 and 118: 5.3 Light Surface 111An example of
Page 119 and 120: 5.3 Light Surface 113the other two
Page 121 and 122: 5.3 Light Surface 115Complex geomet
Page 123:
5.3 Light Surface 117Another exampl
show all

mental ray Architectural and Design Visualization Shader Library

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?