Note:
there is main online mirror of this document. It may be more
up to date than this file.
Readme for Volumetrics beta0.9: Essentials
Legal
This package and contents of this package is (C) 2006
Dmytry Lavrov.
You may freely redistribute Derived Works based on .mjw files
contained in this package in the "worlds" subfolder, and
the worldfiles or images you create using this software.
You may not redistribute or resell this package or any portion of it.
Disclaimer
This package and all contents is provided
AS IS, with NO warranty, express or implied. This package or
any portion of it is free for non-commerical(not-for-profit)
use only.
Please do not email this package to friends and instead
direct them to the download page.
Some general statements about this release
Requirements
To use Volumetrics you need mojoworld 3.0 with 3.1.1 update installed, preferably
Professional edition.
Note: this plugin will NOT function properly without 3.1.1 update.
If you have not registered on pandromeda and mojoworld.org forums yet, it's time
to register, at least to get tech support and benefit from information posted on
mojoworld.org forums. Volumetrics is complicated software; you
will need access to official forums and technical support. By buying MojoWorld
you are supporting Pandromeda and development of new features and enhancements.
Future
Current version beta0.9 is provided for free;
but future versions (starting from 1.0) will most likely be
paid. This beta has limited content; version 1.0 will have
some usability and performance improvements, bug fixes, and
will be released together with larger library of presets and
cloud types.
Rendertimes
Rendertimes it's quite flexible thing,
especially with very flexible software where everything is
defined by user. You can create top-quality perfect sunset
you can afford to render overnight, using complicated
functiongraph for density, and render with overkill settings,
or create clouds for animation that goes at 3 minutes per
frame but has a bit of noise and uses very simple density
function.
Installation instructions
Exit MojoWorld if it is
running. Copy the volumetrics.dll from appropriate
subdirectory( mac/ or windows/) to your plugins folder ( on
windows, typically, c:\program
files\pandromeda\mojoworld3\plugins ) (if you have already
installed volumetrics, overwrite old dll) Make sure you don't
have old volumetrics.dll (if you're on Mac , make sure there
isn't both "Volumetrics.dll" and "volumetrics.dll") . To load
worldfiles supplied with this distribution, you will need
latest 3_0_dlfunctions.dll file , get it from
my
plugins page and xa_function plugin from
Bernard's plugins page
Testing installation
Start MojoWorld. You should be
able to load, render and modify worlds supplied in this
package. For rendering, you may want to change volumetrics's
rendering settings, as explained in Rendering settings section
below. If during startup you see "ID Clash" messages, then you
probably have old and new versions of some plugin installed
simultaneously. This could happen with two versions having
names like 3_0_dlfunctions.dll and DLFunctions.dll . By
timestamps, find what one is older, and change file extension
of old ver. to say 2ll , or move it to other directory, then
restart MojoWorld.
Accessing the Volumetrics from within
MojoWorld
Volumetrics is plugged as "atmosphere" and is
accessed from Sky Editor (cloud-like icon), same as with
previous beta0.5.
Tooltips
Volumetrics has useful tooltips on all
parameters. You can also use
this
list of tooltips Try hovering your mouse over parameter
name to see the tooltip (you may need to set smaller tooltip
delay in the preferences of MojoWorld). Tooltips explain how to
use the parameter, and give recommended values.
Rendering settings (IMPORTANT!)
In a way, Volumetrics
is a rendering engine, and has few rendering settings on it's
own. Load some sample world file, open Sky Editor, and look in
the volumetrics's settings. The most important setting for
clouds rendering is
Vol. lighting
resolution. It specifies resolution of lighting
computations performed by Volumetrics for clouds. Higher
resolution gives better quality, but increase render time and
RAM usage. For previews, use ~500, for final, use 2000 . You
may need even higher values for space shots. You can see other
settings in the
Rendering
subsection section of volumetrics parameters. Consult the
tooltips for usage instructions.
Antialiasing
Typically, Volumetrics works allright
with lower Antialiasing
settings (set in mojoworld). Antialiasing=3 works fine.
Geometry Detail has no effect
on the isosurfaces or clouds.
Loading old Volumetrics worldfiles
Volumetrics now
support clouds and atmosphere shadows (see below), so the
worldfiles may look different. To make worldfile look as with
old version, uncheck Shadows
parameter (located in Rendering subgroup)
Making terrains with Isosurfaces
You can make terrains
as described in
this tutorial. Isosurface terrains seems to render faster
than standard mojoworld terrains, and allows greater
flexibility, both for realistic terrain generation and
surrealistic effects.
Creating, deleting, loading, and saving individual
"layers"
In the Volumetrics, you can see DDLBs labelled
0,1,... (initially there's single DDLB labelled 0). You can
click on it to open menu where you can create surface or
clouds, or save/load. Then you can click on < to open it and
edit parameters.
Integrating with existing MojoWorld planets
You can
open one of example worlds, open
Sky
Editor[not stars editor], and save to library. Then you
could open MojoWorld planet of your choice and load the
atmosphere via Sky Editor. You will probably need to adjust
"lowest altitude" parameters for atmosphere "layers" in the
Volumetrics to match lowest altitude of terrain. Otherwise you
(for example) will not have any atmosphere below zero altitude
(and it'll look kinda strange).
Making planet receive the shadows cast by clouds
- Open sunlight editor (in
answer to one very frequently asked question, it is NOT
sun editor. Please make sure
you're really opening sunlight
editor)
- in the Sunlight Color
parameter choose Function
(sorry, it is MojoWorld 3 pro only feature)
- in the menu, use Create New
Node, in Category
choose Volumetrics, in
Nodes choose "Vol. shadows
for mojo..." and click OK to create the node. Connect
output of "Vol. shadows for mojo..." to Sunlight
Color.
Volumetrics should now cast shadows onto mojoworld
objects and terrain. If something doesn't work, please
re-check that you really did it in
Sunlight Editor (not sun editor). To make
volumetrics receive shadows cast by MojoWorld objects and
terrain(if shadows is on in the mojoworld render settings),
check "Receive shadows from mojo" checkbox in the volumetrics
(
Rendering subgroup). This
could make renders much slower - mostly because mojoworld's
own Full Shadows are really slow, especially for terrain.
Making planet have ambient lighting defined by
volumetrics
Open ambient light
editor (you can access it through object list). In the Ambient Color functiongraph do mostly same
thing as explained above, but this time using "Vol. Ambient
for mojoworld." node.
Possible pitfalls:
Sunset/sunrise or night renders are too bright:
By default, MojoWorld planet doesn't cast shadows onto clouds. And in real world
(and volumetrics) the sky is dark at night because it is shadowed by the planet.
There is few ways to solve problem:
First:
create additional surface layer with Shape=-1
(shape=-1 makes isosurface be solid everywhere between
Lowest altitude
and Highest altitude).
You will need to set lowest and highest altitude so the surface is everywhere
below your terrain.
Second:
Turn on full shadows on planet and turn on "receive shadows from mojoworld".
But it will be very, very slow. It isn't recommended.
Third:
make isosurface terrain instead(consult the tutorial
(avaliable wia mojoworld.org forums.
Fourth: use isosurface ocean from one of sample worlds
(note: it's locked on zero altitude, for some reasons
(realism when used together with volumetric atmosphere))
The atmosphere settings in sample worlds is realistic(except
Alien Jungle); e.g. the height of atmosphere and clouds
layers is made to be similar to that of Earth. Other planets
may be not following this convention, and e.g. use terrain
that goes from -10km to 200km high. Also, do not expect
atmosphere to necessarily look Earth-like with non Earth-like
settings. The goal of volumetrics is to render specific
atmosphere with maximal accuracy; for "alien" settings, it
means that atmosphere will also look "alien", quite possibly
in some way that is outside the box.
Explanations of certain aspects of Volumetrics and/or
sample worldfiles provided
Volumetrics has it's own lighting/shadowing
system.
Everything in the Volumetrics can cast "shadows"
i.e. alter lighting. Air, mist, clouds, isosurfaces, etc.
Volumetrics's "shadows" is not "on or off" but can have
different colors depending to the shadowing media.
For example, "shadow" of atmosphere is what makes sunsets be
red in real world; so does it in the Volumetrics. Shadows of
clouds or mountains also make rays and lightbeams in real
world; so they do in the Volumetrics. The darkness of
"shadow" cast by volumetric layers can be controlled with
Shadow Darkness parameter.
Accurate lighting has certain implications though. When you
specify the Extinction color
in one of atmospheric layers, it also changes the lighting at
sunrise/sunset. In a way it is great - you get realistic
lighting for alien atmosphere. But it can sometimes produce
results that might be unexpected to new users (like pink atmo
will make sunlight green at sunrise/sunset). The Reemission behaves in more predicable way;
you can think of it as of color of dust particles in the air.
The Emission is just like
glow; it is also used as ambient for air and/or clouds.
Colors at sunset/sunrise
Read previous section. It is
recommended to have sunset colors in the sunlight turned off
(don't forget to do that if you are adding volumetrics to
older worldfile). When there's two sunset coloring effects
(mojoworld's and volumetrics's) applied simultaneously things
get unnecessarily confusing. Try thinking outside the box...
for example imagine what effects you can achieve with
accurate sunset lighting that you get in Volumetrics.
Colors in RTR versus colors in render
The RTR does
not render volumetric shadows; in result, the RTR colors are
often different from render colors. For example, dark sunset
image will appear bright in RTR because of lack of shadowing
that makes render much darker (and also makes it red as
explained above).
Shaders
Isosurfaces can not use usual mojoworld
materials and need to use special shader instead. When
creating isosurface, in the Shader parameter, you need to
select "Simple shader" (without shader, surface will be drawn
in uniform grey color). It works similarly to materials.
Containers
Isosurface has Container parameter where
you can select any mojoworld object, so the isosurface will
be restricted to inside of this object. When you do that, you
can use object position from inside the isosurface, and it
will work like object position in the container object. You
need to make object itself be invisible via Object List (if unclear, consult mojoworld
manual)
Haloes
The halo around sun in sample worlds usually
much smaller than that you get with standard MojoWorld
atmosphere. The sample worlds is realistic; them do not try
to "fake" lens glare effects that happen in human eye or in
photocamera. It could be applied in postwork if desired, or
you could change the Anisotropic preset.
Blocky artifacts
If, after modifying some worldfile,
you get blocky artifacts, you need to turn on Adaptive if it isn't on yet, or increase
Reliability parameter
(internally, volumetrics does some dark voodo to make things
render faster, but like almost any other procedural rendering
optimization it can sometimes produce artifacts. Fortunately
it allows you to eliminate artifacts at cost of render time)
Use with MultiAtmos
Just don't do it, there's no need
to. You of course could do that and it will probably sorta
work, but it's usually better to think outside of old box.
You can just add another Volumetrics layer (as Volumetrics
can do everything any other mojoworld atmosphere plugin can
do, and MUCH more).
Use of various strange atmosphere coloring hacks
originally created for standard mojoworld atmosphere by Eric,
myself, or somebody else
Fortunately, there's no need to
use such things in the volumetrics, as these effects can be
achieved in more natural way. You don't need to nail
horseshoes to tires, and don't need to put tires on horse's
legs...
Improved ambient lighting
In the Ambient subgroup, you can see different
parameters for ambient lighting. By carefully adjusting
ambient lighting, you can greatly improve realism of your
landscapes. Consult the tooltips for usage instructions.
Additional information
For general MojoWorld issues,
consult MojoWorld documentation.
On
this page you can find some additional useful information
written for volumetrics beta0.5 (still valid). Especially
isosurface landscape tutorial. I will write similar tutorial on
making clouds from scratch.
You can ask questions on
mojoworld.org forum, section
Volumetrics. Note: I will
answer
only questions posted on mojoworld.org or asked
in mojovox when i'm logged in. No emails, no PMs, no answers on
other forums, no exceptions. The questions and answers needs to
be keept in one place & i will not have time to harvest
common Q&A from several forums when working on
documentation.