Brazil r/s User Manual

alpha version
for Brazil 0.2.x
September 07, 2001

Introduction

The Brazil Rendering System is a new advanced rendering system developed within a production environment to meet the demanding, exacting, and varied requirements of professional artists.

About This Guide

This documentation guide is separated into seven main sections detailing the Brazil Rendering System and one section answering some commonly asked questions. Each of the sections will describe in detail the features available to you. These sections will describe what each feature does and will present examples of how those features affect the outcome of your images. This is not meant to be a tutorial, but rather a reference for all the working features of Brazil r/s.

NOTE:  This document is under active development - more info will be added as it becomes available

Should you run into problems while using Brazil r/s, there are several methods by which you may find answers to your questions, listed below:

Frequently Asked Questions (FAQ):

The eighth section of this guide is organized as a mini-FAQ -- it deals with a select few of the frequently asked questions that have been brought up since the introduction of the Brazil r/s. Many of the most common problems are solved if you look through this section of the documentation. A more extensive and complete FAQ can be found on the SplutterFish website at http://www.splutterfish.com/sf/faq.php3

Blur Beta Message Board:

There is a web-based Brazil r/s community currently active at the Delphi Forums. Many users frequent this board, making it another valuable resource to help find answers to questions you may have. Use the following link to access the message boards. http://www.delphi.com/blurbeta

SplutterFish IRC:

Splutterfish is running an IRC server where you may go to discuss Brazil r/s. The easiest way to access the server is through the web client found at http://www.splutterfish.com/sf/gettinghelp.php3.  Click the link, "#Brazil_r/s chat" to get started.  If you prefer to use your own IRC Client software (like mirc),  connect your IRC client to irc.splutterfish.com on port 5999 and log into channel #Brazil_r/s.  Feel free to use this channel if you  need help or just drop in and chat with others in the community.


There is no technical support provided for Brazil r/s, as it is still in an alpha state, and is treated as such. We ask that you use the above resources to find help with any problems that you may have with the product.

Table of Contents

The documentation is organized into seven sections, listed below:

Section 1: What's new in Brazil r/s 0.2.0?

This section details what has changed from the 0.1.4 version to the new 0.2.0 version.

1.1  Render Dialog
1.2  Scene Management
1.3  Raytracing
1.4  Frame Buffer
1.5  Anti-aliasing Changes
1.6  Improved Lighting
1.7  Global Illumination Sampling
1.8  Renderer Independent of Max
1.9  Time Lock

Section 2: General Options

This will introduce you to the general parameters such as bucketing and multithreading.

2.1  Frame Buffer

2.1.1  Auto Launch
2.1.2  Auto Foreground
2.1.3  Channels
2.1.4  Storage
2.2  Tools
2.2.1  Console Options
2.2.1.1  Auto Launch
2.2.1.2 Clear on new frame
2.2.1.3 Verbose Level
2.3  Bucketing Options
2.3.1  Size
2.3.2  Order
2.4  Multi-threading Options
2.4.1  On
2.4.2  Low Priority Thread
2.4.3  Use All Procs

Section 3: Sampling Parameters

This section contains information on image sampling control and depth of field sampling.

3.1  Image Sampling Control

3.1.1  Sampling Display
3.1.2  Min Samples
3.1.3  Max Samples
3.1.4  Search Radius
3.1.5  Low Contrast/High Contrast
3.1.6  Show Adapt Samples
3.1.7  Object Edge
3.1.8  RPrim Edge
3.1.9  Smooth Groups
3.1.10  Don't Anti-alias
3.2  Depth of Field Sampling
3.2.1  On
3.2.2  Min Samples
3.2.3  Max Samples
3.2.4  Focal Blur
3.2.5  Jitter
3.2.6  Focal Distance
3.2.7  Bokeh

Section 4: Filtering Parameters

This will give insight into the image filtering and 2D map filtering.

4.1  Image Filter

4.1.1  Area
4.1.2  Mitchell-Netravali
4.2  2D Map Filtering
4.3  On
4.4  Derivative Blur/Bump Derivative Blur
4.5  Blur Offset/Bump Blur Offset

Section 5: Ray Server Parameters

This section contains all of the raytracing controls and ray acceleration settings.

5.1  Ray Tracing Depth Control

5.1.1  Reflected
5.1.2  Refracted
5.1.3  Total
5.1.4  Auto Cutoff
5.2  Options
5.2.1  Secondary Effects
5.2.2  Raytrace Reflections
5.2.3 vRaytrace Refractions
5.4  Ray Tracing Acceleration
5.4.1  Space Subdivision
5.4.1.1  Mode
5.4.1.2  Speed
5.4.2  Nested U Grids
5.4.2.1  Max Size
5.4.2.2  Max Depth
5.4.2.3  Max Polys
5.4.2.4  Balance
5.4.3  Clusters
5.4.3.1  Max Clusters
5.4.3.2  Max Depth
5.4.3.3  Max Volume (%)
5.4.4  Hierarchical Bounding Volumes
5.4.4.1  Mode
5.4.4.2  Spheres
5.4.4.3  Boxes

Section 6: Luma Server Parameters

The Luma section contains the settings that control light management and global illumination.

6.1  Direct Illumination

6.1.1  Enable
6.1.2  Point Lights
6.1.3  Area Lights
6.1.4  Sky Light
6.2  Secondary Illumination
6.2.1  Enable
6.2.2  Point Lights
6.2.3  Area Lights
6.2.4  Sky Light
6.2.5  Allow Caustics
6.2.6  Volumetrics
6.3  Miscellaneous
6.3.1  Shadows
6.3.2  Allow Default Lights
6.4  Global Illumination
6.4.1  Shade Rate
6.4.1.1  Min
6.4.1.2  Max
6.4.1.3  Contrast
6.4.1.4  Lock To Image Rate
6.4.2  Sampling Control
6.4.2.1  Sampler
6.4.2.2  Rate
6.4.2.3  Bounces
6.4.3  Secondary Energy Filters
6.4.3.1  Diffuse
6.4.3.2  Specular
6.4.4  Sky Light
6.4.4.1  Color
6.4.5  Shader Degradation
6.4.6  Mode
6.4.7  Start Depth

Section 7: CSG Server Parameters

Contains parameters for csg Primitives.

7.1  Ground Plane

Section 8: Frequently Asked Questions (FAQ)

Here you will find the most commonly asked questions and problems that people have with Brazil r/s.

Brazil Rendering System User-Reference

Section 1: What's new in Brazil r/s 0.2.0?

Brazil r/s 0.2 is much faster than it was before. A better question to ask may be, "what isn't new in Brazil r/s 0.2.0?" A large number of changes have been made to the rendering system since the last build.

1.1  Render Dialog

The greatest of these changes is that Brazil r/s is no longer a render effect, but a complete rendering plugin. Brazil r/s  will still support the old render effect on scenes coming from the older 0.1.x builds, but you will no longer be able to add the render effect on new scenes.

1.2  Scene Management

Scene management has been greatly improved in this release. Whereas the previous alpha used the scene enumeration provided by Max's scanline renderer (basically a scene enumeration is a way of formatting your scene such that a renderer can render it), this alpha creates its own scene enumeration. The advantages? Memory management is now under Brazil r/s' control, allowing for many optimizations in memory consumption and speed that were unavailable before. Objects such as patches and csg primitives will be rendered natively without being converted into polygons in future releases. And it makes life easier when Brazil r/s becomes multiplatform, since the core of Brazil r/s will not require modifications when trying to interface with a new 3d application.

1.3  Raytracing

Raytracing has received a large overhaul since the 0.1.4 release. Many processes have been consolidated and the code is written in a more machine friendly manner. These things lead to a strong speed increase when doing reflections and refraction.

1.4  Frame Buffer

Brazil r/s now uses its own frame buffer, separate from Max's default virtual frame buffer. Brazil r/s' frame buffer stores color information in 128-bpp color resolution using a 32-bit floating-point number for each color channel. This allows image modification without the typical banding effects you might see with the default VFB. The Brazil r/s frame buffer now implements bracketing around the current bucket that is being rendered.

1.5  Anti-aliasing Changes

Anti-aliasing control has been enhanced, including options to specifically handle anti-aliasing of smoothing groups and object edges, better adaptive sampling, and the ability to "undersample" your image. What is undersampling? Undersampling allows you to tell the sampler to actually skip pixels and blend across the skipped spaces. This is a great option for generating fast previews.

1.6  Improved Lighting

The skylight now uses the new raytracing pipeline, which leads to an increase in speed. Point lights that use Max's raytrace shadows now swap the shadow type for Brazil r/s' native raytrace shadows which are optimized for larger scenes.

1.7  Global Illumination Sampling

You are now able to adjust GI samples separately from image samples. This lets you get crisp geometry antialiasing while retaining fast GI in areas where the GI illumination varies very little. There is also the option of undersampling the GI solution - giving you more control of render times vs. quality.

1.8  Renderer Independent of Max

The Brazil r/s rendering engine, as a result if being more decoupled from max than a traditional plugin renderer, allows you to change and edit your max scene while rendering.

1.9  Time Lock

Because many of the features available now allow Brazil r/s to be nearly production ready, a time-locking system has been implemented with this release. The current time lock will be good for 60 days from your first use and it will be renewed with each subsequent release of a new test (alpha and beta) build. Making changes to your system clock may trigger any of your Flex or CDilla licenses to detect an attempt to crack or circumvent you software licenses. Doing so may permanently disable or in some other way muck up your ability to run max and/or other software you may depend upon. Please don't just reset your system time in an attempt to keep Brazil r/s working - The risks are too high and it's just not worth the hassle.

Section 2: General Options

Figure 2.1 Brazil r/s General Options
 

The General Options have changed a fair amount since the last build. Bucketing parameters are now included in this section.

2.1  Frame Buffer

The frame buffer section contains several options that affect the way in which your renders appear in Brazil r/s' frame buffer. In its current state, the Brazil r/s frame buffer has all of the default features that the MAX scanline buffer does, and will have many new options added to it in future releases.


Figure 2.2 Brazil r/s Virtual Frame Buffer
 

2.1.1  Auto Launch
The Auto Launch checkbox is used to open the frame buffer window when a render starts. If it is checked, the window will automatically open.
2.1.2  Auto Foreground
When the render is launched, this will automatically bring the frame buffer to the foreground after the preprocessing finishes and the image begins to render.
2.1.3  Channels
These are the type of channels to render to the frame buffer. There is currently only one option, standard RGBA.
2.1.4  Storage
Defines how the pixels in the Frame buffer are stored. Currently only one option, floating point colors.

2.2  Tools

2.2.1  Console Options
2.2.1  Auto Launch
This is very similar to the frame buffer's Auto Launch checkbox, but instead, this controls the automatic opening of the console window.
2.2.1.2  Clear on new frame
When this checkbox is active, the Brazil r/s console will clear itself each time a render is started.
2.2.1.3  Verbose Level
The Verbose Level controls the amount of feedback returned by the renderer to be displayed in the console. The higher the verbose level, the more info you'll see.

2.3  Bucketing Options

2.3.1  Size
This number denotes the size of each bucket in pixels squared.


Figure 2.4 Bucketing Size

2.3.2  Order
The Order option allows you to choose the order in which the buckets render. Choosing Top to Bottom will render rows of buckets from left to right, beginning with the top row and working its way down. The Left to right option will render columns of buckets from top to bottom, beginning with the left column of buckets and working its way to the right. Center Out works from the center of the image to the outer edges. Choosing the Random option will randomly select buckets to render. The final option for order is the Priority Map. Choosing this option will enable the priority map slot below, which is used to assign the map. The Verbose Level controls the amount of feedback returned by the renderer to be displayed in the console. The higher the verbose level, the more info you'll see. Any of these methods can run in reverse order if you turn on the "R" button next to the order drop down.


Figure 2.5 Bucketing Order
 

2.4  Multi-threading Options

2.4.1  On
Very straightforward, this is where you turn multithreading on and off.
2.4.2  Low Priority Thread
This checkbox allows you to turn the priority of rendering to a low priority thread, allowing other processes to take precedence before it.
2.4.3  Use All Procs
By turning this option on, you will enable all of the processors in the machine to be used to render buckets. If you disable this option, the Threads option will become available, allowing you to define the number of threads you would like to use.

Section 3: Sampling Parameters

Figure 3.1 Image Sampling Rollout
 

3.1  Image Sampling Control

3.1.1  Sampling Display
The sampling display is much easier to read with the newest build. As you will note, it tells you the min and max rates used for the image sampling. These numbers, [-2x-2] and [2x2] in figure 3.1, represent the number of samples used per pixel. In the case of figure 3.1, the minimum samples per pixel would be one sample for every four pixels, and the maximum would be four samples for every pixel. This display is much easier to read and gives you a better insight as to what the sampling does for your images.
3.1.2  Min Samples
The min samples used to anti-alias your images. For example, a value of 1 will render 4 samples around the given pixel and then average their values to form your pixel color. More samples means a more accurate pixel color, and smoother looking anti-aliasing. More samples also means longer render times.
3.1.3  Max Samples
This is the maximum number of samples that could possibly contribute to your pixel. In areas the renderer defines as requiring more samples, it will sample up to this number. As in, if you set min to 1 and max to 3, it will render every pixel with at least 4 samples, up to a maximum of 64 samples in problem areas where it detects bad aliasing. When your max is larger than your min, you are now performing something referred to as "Adaptive sampling."
3.1.4  Search Radius
The Search Radius is the pixel distance to perform the Adaptive sampling tests. Currently disabled, it may be removed from the final release.
3.1.5  Low Contrast/High Contrast
These two items are used to compare the contrast between samples needed to trigger the adaptive sampling for that pixel.
3.1.6  Show Adapt Samples
This option allows you to see where extra samples are being used in your renders. The color picker to the right lets you choose a color to represent your adaptive samples. In areas with a high concentration of adaptive samples, the color from the color picker will be placed on your images. This is most noticeable at the edges of objects.
3.1.7  Object Edge
By turning on this option, the engine will check for a change in edges of the objects, and if adaptive sampling is enabled (by specifying a max value higher than your min value), will sample that area up to the max sample amount.
3.1.8  RPrim Edge
RPrim is a Brazil Rendering Primitive. An RPrim represents any geometric 'thing' that Brazil r/s can render. Each face in the mesh of a max object is an RPrim -- CSG objects are also RPrim objects. This anti-aliasing switch will turn on the adaptive sampling of the edges of the RPrim objects (such as the edges of faces in a mesh).
3.1.9  Smooth Groups
This operates in the same manner as the Object Edge option, but checks the smoothing groups for changes and applies appropriate anti-aliasing.
3.1.10  Don't Antialias
This disables all antialiasing settings you may have set. Click this for non-antialiased test images. Note that if you're shooting for fast preview renders, undersampling you images might be a better approach.

3.2  Depth of Field Sampling

Figure 3.2  Depth Of Field Sampling Rollout
 
3.2.1  On
This is the toggle for turning depth of field on and off.
3.2.2  Min Samples
This is very similar to the image samples; it operates on the number of samples used to calculate the depth of field. Increase to get rid of noise that may appear in the render.
3.2.3  Max Samples
The Max Samples are used to oversample the depth of field calculation. This is implemented in the same manner as the Max Samples for the Image Sampling Control. Currently disabled for this release.
3.2.4  Focal Blur
This is rather straightforward in that the Focal Blur setting dictates how much the scene will blur in the areas in front of and behind of the focal point.
3.2.5  Jitter
The Jitter setting is the random distribution of the samples. This prevents any normal patterns of sampling in the different buckets.
3.2.6  Focal Distance
This is the distance from the camera to the focal planes. Objects falling on the plane at this distance will appear completely in focus in the rendered image. By using the distance between the camera and the camera's focal point, you can easily figure out what this number needs to be in order to have your objects in focus.
3.2.7  Bokeh
The bokeh filter is a phenomenon in photography, where parts of an image that are extremely out of focus and are very bright will "bloom," causing large rings or other shapes to appear in the image. Think of an image of a street at night that is out of focus. All of the street lamps that are out of focus will usually show up as large octagons or hexagons. This is the bokeh effect. There are currently four options that you can use. The default bokeh setting is to use the current antialiasing filter. You can use all the filters available in Max to generate bokeh that falls off at the edge of the lens. The second option, Flat Disc, is the normal even disc distribution. Linear and Exponential are used for creating rings. When you choose the Exponential setting, a spinner is enabled to control the exponent.


Figure 3.3 Showing the different settings at work.
 

Section 4: Filtering Parameters

Figure 4.1  Image Filtering Rollout
 

4.1  Image Filter

The Image Filter settings are similar to the current antialiasing filters available in the default Max scanline renderer. Currently Area and Mitchell-Netravali are the only filters available. When you select a filter, a brief description shows up below the selection box and the options for that filter become available to the right.


Figure 4.2 Image Filters
 

4.1.1  Area
The area filter is the default filter used from the original version of Max. It is a very simplistic anti-aliasing method, slightly blurry. Adjusting the radius setting will modify the area used for sampling.
4.1.2  Mitchell-Netravali
The Mit-Net filter is used to trade off between the two parameters of blurring and ringing. Weighting these two parameters in different ways will actually achieve other filter effects. Setting Blur to 0.0, and Ringing to 0.5 gives the Catmull-Rom filter. 0.0/1.0 is a Cubic filter. This is a better filter than the area filter overall, with usually sharper results

4.2  2D Map Filtering

The 2D Map Filtering determines how bitmapped textures are filtered in your scene.

4.3  On

This turns the map filtering on and off.

4.4  Derivative Blur/Bump Derivative Blur

This is the multiplier to Blur Offset for maps on faces whose normals are perpendicular to the camera. I.e.: increasing this increases blurring of maps at the edges of objects (faces that are
perpendicular to your view).

4.5  Blur Offset/Bump Blur Offset

Overall amount of blur applied to maps

Figure 4.3 Different Derivative Blur and Blur Offset Settings
 

Section 5: Ray Server Parameters

5.1  Ray Tracing Depth Control

Figure 5.1 Ray Server Parameters Rollout
5.1.1  Reflected
This number represents the maximum number of times that a ray will be reflected off of surfaces in the scene. If you have one object in your scene that reflects the environment, you can keep this number low. When you have many objects reflecting, you will want to increase this number to make the scene appear more realistic. Increasing the number of reflections will also increase the amount of time that your render takes. The effect of increasing the number of reflections is illustrated in figure 5.2 rather clearly. By increasing the samples in figure 5.2, we are able to more realistically represent the way the reflection would look if we had two mirrors facing one another. In reality, the scene would reflect itself forever, which is the equivalent of making this number very, very high.


Figure 5.2 Illustration of how the increasing of reflection depth affects the image

5.1.2  Refracted
This number works in the same manner as the Reflected option. Increasing this value will allow the number of total refractions that a ray executes to increase.
5.1.3  Total
This is the total (reflected + refracted) number of bounces that a ray will undergo. If you have Reflected set to 10, Refracted set to 10, and Total set to 10, you will only have 10 total bounces. This can be 10 reflections, 10 refractions, or any combination of reflections and refractions that totals 10.


Figure 5.4  Reflection/Refraction set to 3/3


Figure 5.5 Reflection/Refraction set to 7/7


Figure 5.6 Reflection/Refraction set to 12/12

5.1.4  Auto Cutoff
If the contribution of a reflected or refracted ray to the color of your pixel is less than this cutoff amount, the ray will stop bouncing. Reduce this number if subtle reflections aren't showing up, or increase to gain speed if you don't notice the difference.

5.2  Options

5.2.1  Secondary Effects
This is used to disable or enable all of the Secondary Options listed below.
5.2.2  Raytrace Reflections
This checkbox enables and disables all of the reflection calculations in the scene.
5.2.3  Raytrace Refractions
This checkbox enables and disables all of the refraction calculations in the scene.

5.3  Secondary Effect Options

5.3.1  Enable Self Reflect
Turns on or off the ability to have an object appear in its own reflection.
5.3.2  Secondary Atmospherics
Turns on or off the ability to reflect / refract atmospheric effects.
5.3.3  Secondary Material IDs
Turns on or off the option to allow material Ids to reflect/refract. For example, an object with a material ID of 2 will only return proper Material Ids as it passes through a refractive object if this checkbox is checked.

5.4  Ray Tracing Acceleration

The method Brazil r/s uses to accelerate its raytrace calculations. The Null Accelerator is no acceleration. Default is Default Accelerator.


Figure 5.7  Ray Tracing Acceleration Rollout
 

5.4.1  Space Subdivision
5.4.1.1  Mode
This allows two ways for the acceleration settings to be implemented. The first is Manual Hybrid, which will use individual objects and groups to calculate grid settings. The second mode is the Single Grid, which will put all objects in the same grid. Manual Hybrid is excellent for speeding up scenes in which objects are far apart in the scene. By separating the grids, each one can be calculated more efficiently than if they were together on the same grid.
5.4.1.2  Speed
The speed settings are a good measure to get acceleration settings out of the system. Faster is better, which is why the High option is set by default. This will use more memory than the low system, but will improve the speed of the ray acceleration.
5.4.2  Nested U Grids
The voxel grid is similar to boxes in space that surround pieces of geometry. Trying to find a triangle with a ray is expensive, finding a box is much faster. So as a raytracer, technically, you trace the ray looking for boxes. If you hit a box, then you have to check if you hit any of the triangles inside that box. By breaking the grids up in an orderly fashion, you are able to speed up the process by eliminating unnecessary ray casting.

NOTE:  This document is under active development - more info will be added here in the future

5.4.2.1  Max Size
5.4.2.2  Max Depth
5.4.2.3  Max Polys
5.4.2.4  Balance
5.4.3  Clusters
5.4.3.1  Max Clusters
5.4.3.2  Max Depth
5.4.3.3  Max Volume (%)
5.4.4  Hierarchical Bounding Volumes
5.4.4.1  Mode
5.4.4.2  Spheres
5.4.4.3  Boxes

Section 6: Luma Server Parameters

The Luma Server is where you control the light settings of all lights used in Brazil r/s renders. These lights include all of the default max lights, area lights, geometry lights, and Brazil r/s' sky light. Here you to have control to enable and disable all lights and shadows, and you also control the sampling and the behavior of the lights.

Figure 6.1 Luma Server Rollout
 

6.1  Direct Illumination

6.1.1  Enable
This enables and disables all direct illumination in the scene for all of the selected light types below.
6.1.2  Point Lights
When checked, this will allow point lights (omni, spot, direct) to cast direct light (as opposed to bounce light) onto the objects in the scene. If this box is not checked, your point lights will not directly affect the lighting of the scene -- they may still affect the secondary illumination (bounce light) if you have the Secondary Illumination checkboxes configured to do so.
6.1.3  Area Lights
When checked, this will enable Brazil r/s' area lights to directly illuminate the scene. This will be enabled once Brazil r/s' Area Lights are included.
6.1.4  Sky Light
When checked, this will allow Brazil r/s' sky light to directly illuminate all the scene objects. The skylights settings can be modified in the Sky Light settings of the Luma Server Parameters.

6.2  Secondary Illumination

Secondary Illumination (bounce light) is used to simulate the nature of light reflecting off of one object and on to other objects, further illuminating the scene.
6.2.1  Enable
This enables and disables all direct illumination in the scene for the selected light types.
6.2.2  Point Lights
When checked, this will allow objects to receive secondary illumination (bounce light) from objects that are lit by your scene's point lights (omni, spot, direct). If this box is not checked, your point lights will not affect the secondary lighting of the scene.
6.2.3  Area Lights
When checked, this will allow an object to receive secondary illumination (bounce light) from objects that are lit by Brazil r/s' area lights. This will be enabled once Brazil r/s' Area Lights are included.
6.2.4  Sky Light
When checked, this will allow objects to receive secondary illumination created when objects are lit with Brazil r/s' sky light. The sky light's settings can be modified in the Sky Light settings of the Luma Server Parameters.
6.2.5  Allow Caustics
This enables caustics to be projected onto objects in your scene. Currently this only works with geometry lights and the skylight.
6.2.6  Volumetrics
Turning this option on will allow volumetrics (atmospherics) to be illuminated and to illuminate your scene.

6.3  Miscellaneous

6.3.1  Shadows
This option turns all scene shadows on and off.
6.3.2  Allow Default Lights
Turns the default lights on and off. Brazil r/s will uses Max's default lighting if no lights exist in your scene, or if all lights have been turned off in other sections of this panel

6.4  Global Illumination

6.4.1  Shade Rate
6.4.1.1  Min
This number represents the minimum rate for the GI samples. A negative value calculates a GI sample less than once per pixel, which is called "Undersampling." For areas where the GI solution doesn't change much over a given surface, a negative value will look fine and render much quicker (since it's producing less samples). Increase Samples to get rid of munge, which is a blocky artifact created by undersampled GI.
6.4.1.2  Max
Areas that fail the contrast test will reach a shade rate of this maximum value. Similar to how image samples have a min and max value.
6.4.1.3  Contrast
The amount of deviation allowed between samples before Brazil r/s starts adaptively sampling the GI.
6.4.1.4  Lock To Image Rate
Locks shade rate to image rate, which returns GI to how it used to work in 0.1.4. Artifacting will change from smudgy munge back to grain. This is left in for all you grainaholics out there.
6.4.2  Sampling Control
6.4.2.1  Sampler
This is the method that Brazil r/s will use to gather the global illumination samples.  The Simpe Quasi Monte Carlo sampler is the default sampler used.  The slower, Blind Monte Carlo sampler is also an option. (Adaptive Quasi Monte Carlo, pictured below, is not available in this release)


Figure 6.2 Sampling Control Options

6.4.2.2  Rate
This is the sampling rate used by the GI sampler to generate global illumination. By using a higher sample rate, you will increase the number of GI samples, and have a more accurate GI solution. This leads to a better image, but it also leads to an increase in rendering times.
6.4.2.3  Bounces
Number of times a GI ray will bounce around the scene before stopping.
6.4.3  Secondary Energy Filters
6.4.3.1  Diffuse
This lets you control the strength and color of diffuse secondary light. Any light that is reflected by a diffuse material will use these settings.
6.4.3.2  Specular
This lets you control the strength and color of specular secondary light. Any light that is reflected by a specular material will use these settings.
6.4.4  Sky Light
6.4.4.1  Color
This is where you control the intensity and the color of light generated by the skylight. The number spinner allows you to increase the intensity of the light. The color of the light can be adjusted in two ways. The first method is to choose a color in the color selection box next to the intensity spinner. The second method is to assign a map to the skylight. This is accomplished by choosing the map selector next to the color box. When assigning a map to the skylight, you need to set the material's mapping to be "Spherical Environment" in order to correctly use the map.
6.4.5  Shader Degradation
Simplifies the shading information calculated for GI rays. Disabled for the current build.
6.4.6  Mode
Fullshade means that the entire shader is evaluated for every GI bounce, which is more accurate but can be expensive. Quickshade means only the diffuse map is evaluated for GI bounces, unless the Diffuse map checkbox is unchecked, in which case it uses the diffuse color of the material.
6.4.7  Start Depth
The number of bounces before shader degradation kicks in.

Section 7: CSG Server

CSG (Constructive Solid Geometry) are primitives defined by formula instead of by face approximation. For example, a sphere can be simplified as a mathematical formula such as a^2 + b^2 + c^2 = x^2, instead of approximating a sphere with a bunch of connected polygons. Advantages of this technique is first your spheres or other CSG primitives will remain smooth no matter how close you get to them. Formulas also generally calculate a whole ton faster than polys, allowing csg primitives to be intersected by a ray in a fraction of the time and memory overhead.
 

7.1  Ground Plane

The ground plane is the only CSG primitive currently available, with parameters for its height.
 

Section 8:mini-Frequently Asked Questions (mini-FAQ)

8.1.  How do you spell Albuquerque?

Albuquerque.

8.2.  How do I create a good looking glass material?

This question shows up on the message boards very frequently. The best way to create a glass material takes two steps: setting up your material correctly, and setting up your scene correctly.
For your material take the following steps: For your scene, you need something to reflect or refract. This can be done with reflection cards (rectangles assigned a bright white self-illumination material with an output map in the diffuse slot) or by creating a scene in which to put your glass.

8.3.  How do I create light-casting objects?

Creating self-illuminating objects is accomplished most easily by starting with a standard material. In the material editor, set the material's self-illumination to 100. Set the material's diffuse color to pure white and then apply an output map to the diffuse slot. In the output map, you should increase the RGB Output to get the object to emit light. Increasing this will cause more light to be emitted. Also, by increasing the size of you object, you will increase the amount of light it will cast.

8.4.  How do I create caustics?

Currently there are two ways to create caustic effects. The first is to use the geometry lights (see Question 3 above). The second way is to use a skylight.

8.5.  What is the air-speed velocity of an unladen swallow?

ARTHUR: What do you mean? An African or European swallow?
KEEPER: What? I don't know that! Auuuuuuuugh!
BEDEVERE: How do know so much about swallows?
ARTHUR: Well, you have to know these things when you're a king you know.

8.6.  How can I create realistic sunlight?

This varies from scene to scene, but the most common method for creating sunlight in a scene is to use both the skylight and a target light together. Enable the Direct Illumination for both point lights and skylight, and enable the Secondary Illumination for one of the two. Skylight seems to work well with this type of scene. Adjusting the strength of the skylight helps soften the shadows, and adjusting the light multiplier darkens them. Find a mix that works well with the type of scene you are using.

NOTE:  This document is under active development - more info will be added here in the future