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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

  1. 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)
  2. in the Sunlight Color parameter choose Function (sorry, it is MojoWorld 3 pro only feature)
  3. 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.