Note:
there is main online mirror of this document. It may be more
up to date than this file.
Parameters and tooltips of Volumetrics beta0.9
Volumetrics/root:
Preview quality(%)
How precise (approximately) RTR should work. Also have effect
on automatic adjustments. Recommended values: 10..50
Vol. Shadows
Volumetric shadows. Both isosurfaces and clouds can cast this
type of shadows.
Traced shadows
Raytraced shadows; Only Surfaces can cast this type of shadows.
Ambient
Uniform ambient light. I recommend to use light from above,
side and below instead. Currently applied only to
surfaces(reason: in reality, ambient lighting of clouds is
different from landscape's).
Light from above
Ambient light coming from above. Currently applied only to
surfaces. To use it on MojoWorld terrain and MojoWorld objects,
put 'Vol. ambient for MojoWorld' node (Volumetrics category)
into MojoWorld's Ambient Light
Light from side
Ambient light coming from sides. Currently applied only to
surfaces. To use it on MojoWorld terrain and MojoWorld objects,
put 'Vol. ambient for MojoWorld' node (Volumetrics category)
into MojoWorld's Ambient Light
Light from below
Ambient light coming from below. Currently applied only to
surfaces. To use it on MojoWorld terrain and MojoWorld objects,
put 'Vol. ambient for MojoWorld' node (Volumetrics category)
into MojoWorld's Ambient Light
Diffuse sunlight
Ambient light coming from sunlight direction. Currently applied
only to surfaces. To use it on MojoWorld terrain and MojoWorld
objects, put 'Vol. ambient for MojoWorld' node (Volumetrics
category) into MojoWorld's Ambient Light
Opposite sunlight
Ambient light coming from direction opposite to sunlight.
Currently applied only to surfaces. To use it on MojoWorld
terrain and MojoWorld objects, put 'Vol. ambient for MojoWorld'
node (Volumetrics category) into MojoWorld's Ambient Light
Detail
How much detailed fractals must be. Default is good enough; if
you get something looking smoother than it should, increase
this parameter. Values smaller than 1 is not recommended unless
you know what you are doing - it may make your terrain to morph
noticeably when rendering resolution is changed and/or camera
is moved
Lowest detail distance
At what distance details stop decreasing. Smaller values is
slower. Default is good enough, practically no need to change
Max. steps
Currently unused.
Exposure
Works similarly to real photo camera. Bigger values make image
brighter, smaller make darker. You can make stars have proper
brightness and increase this parameter to make nightside
renders
Photofilm
Simulation of photofilm. Usually makes render look more
realistic, but somewhat desaturated. Prevents 'over-burning' of
render if brightness is too big. It is recommended to turn this
on as it helps preserve image for postwork even if render was
under/over exposed (bit like HDRI)
Gamma
Gamma correction. If you feel like, try experimenting with this
parameter. Though, it could be better to do gamma correction in
postwork
Color error
Precision of coloring. Default is good enough, not much need to
change. Smaller values is slower, but normally don't give
noticeable difference in render quality
Vol. lighting radius
If 'Lighting transform method' is set to 'none', defines up to
how many meters away from camera shadows will work. If
'Lighting transform method' is set to 'method1', does nothing
Vol. lighting resolution
Resolution of lighting. For previews, use 500, for final, use
~2000 . Bigger values is better but is also slower and use more
RAM
Lighting transform method
Better set it to method1 unless you're doing animation where
camera moves much. It's some internal thing, no
explanations(sorry). Maybe I should have blocked it in this
release
Lighting top precision(m)
What maximal precision shadows will have. Smaller values give
better quality but are slower and use more RAM. Specified in
meters, currently has effect only if 'Lighting transform
method' is set to method1.
Lighting error bound
Maximal lighting error. Smaller values give better quality, but
use more RAM.
Max. ray bounces
Raytracing: max. number of ray bounces. You may need bigger
values for scenes with lot of multiple reflections
Hide mjw. planet
If checked, MojoWorld planet will not be rendered.
Receive shadows from Mojo
If checked, Volumetrics will receive shadows from MojoWorld.
That is, shadows cast by MojoWorld objects will be visible ON
Isosurfacesand ON Clouds. offtopic: For making shadows cast by
Isosurfaces and Clouds be visible ON MojoWorld terrain, open
Sunlight Editor, and in Sunlight Color, make function graph
with single node 'Vol. shadows ...' (Volumetrics category).You
can get more detailed explanation on website.
Surface
Active
If unchecked, this thing will not be rendered.
Cast vol. shadows
If unchecked, this thing will not cast volumetric shadows.
Cast trac. shadows
If unchecked, this thing will not cast raytraced shadows.
Lowest altitude
Isosurface is contained between lowest altitude and highest
altitude. Also have effect on UVposition in
functions(UVposition.x is 0 at lowest and 1 at highest; you can
use it instead of altitude)
Highest altitude
Isosurface is contained between lowest altitude and highest
altitude.
Shape
Put there texture that controls shape of isosurface. In places
where value is below 0 , you'll have solid, where above, you'll
have clean air. It's somewhat like effect of temperature on
water and ice (where <0 you get ice)
Min step size
Minimal step size. Default should be good enough
Refinement steps
How many refinement steps to do. Default should be good enough
Precision
Precision of intersection solver. Default should be good enough
Adaptive
Automatic adjustments. Works only if RTR preview is turned on.
Reliability
Increase this if you have artifacts. Controls how automatic
adjustment works. Have effect on rendertimes (bigger usually
slower, but not always).
Step scale
This parameter is changed automatically if Adaptive is checked
and RTR is on.
NanoDetails
Experimental parameter. If checked, isosurface will do lighting
with submillimeter precision. Slows things down
Shader
Diffuse
Color of diffuse component
Shininess
How shiny you want specular highlight be (bigger values make it
more shiny, i.e. smaller spot size)
Specular
Color of specular highlight
Glow
Glow color
Reflection
Check it if you want reflections
Refraction
Check it if you want refractions (doesn't work in this version)
Fresnel specular
When checked, like in real world, brightness of specular
highlight will depend to angle of incoming light and to index
of refraction of material (in other words, when it is checked,
specular highlights looks less CG-like and can be more
realistic)
IOR
Index of refraction. Like real world, it has effect on two
things: a.) how much light refracts (something that you
probably knew already :-), b.) what portion of light goes
through and what portion of light reflects off boundary.
(somewhat less widely known effect) Some sample values: air or
vacuum = 1 , water = 1.33 , ice=1.309 , glass = 1.5 to 1.9 ,
diamond = 2.42 . To simulate metals, use large values, like
200, so the reflection will be metal-like
Reflect color
Color of reflection (for most kinds of materials (e.g. water,
glass, polished rock, etc.) use white)
Refract color
Color of refraction (for most kinds of materials (e.g. water,
glass, polished rock, etc.) use white)
Active
If unchecked, this thing will not be rendered.
Lower altitude
Atmosphere is contained between lowest altitude and highest
altitude. These parameters also have effect on UVposition in
function graphs (UVposition.x is 0 at lowest and 1 at highest;
you can use it instead of altitude) so height of cloud layer
can be specified with only lowest and highest alt.
Higher altitude
Atmosphere is contained between lowest altitude and highest
altitude.
Density
Controls density of the clouds. Internally, density is clamped
to 0..1 range. To control overall density, use 'Visibility
distance' instead
Extinction
Defines what color of light is trapped(scattered or absorbed)
the most. For example, if extinction is greenish blue, after
light passes through much atmosphere you will get red because
green and blue was either scattered or absorbed
Reemission(parameter right below) defines how much of this
light is scattered (rest is absorbed). i.e. If extinction is
blue and reemission is white, it blue light is scattered the
most. If reemission is black, blue light is absorbed the most
Reemission
Defines what part of trapped light is scattered (rest is
absorbed). You can think of it as color of dust particles. See
tooltip for extinction.
Emission
Somewhat like glow; defines how much light is produced by
cloud. Can also be used for ambient lighting.
Shadow darkness
Defines how much effect absorbing and scattering have on
lighting (shadowing). Example: 0 = no effect on lighting (no
shadows), 0.5 = half effect, 1 = full effect
Anisotropic
Anisotropic scattering. Rayleigh simulates scattering by
molecules(e.g. scattering by very clean air), others simulate
scattering by fog/dust particles.
Visibility distance(m)
Sort of visibility distance, specified in meters. Smaller
values make denser atmosphere.
Min step size
Minimal step size. Have effect on render times. Good starting
value: 1/15 of 'Free path length' (parameter right above this
one).
Adaptive
Automatic adjustments. Works only if RTR preview is turned on.
Reliability
Increase this if you have artifacts. Controls how automatic
adjustment works. Have effect on rendertimes (bigger usually
slower, but not always).
Step scale
This parameter is changed automatically if Adaptive is checked.
Fixed steps
Obsolete.
Jitter
Jittering amount. Use values between 0 and 1, recommended
value:0.7 for air atmospheres, 0.3 for clouds. Have effect on
image quality, sorta 'color bands versus noise'.