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Chapter 5. The Brazil r/s Render Dialog

Table of Contents

5.7  Ray Server Parameters

5.7.1  Ray Tracing Depth Control

Fig. 5.10  Ray Server Parameters Rollout

5.7.1.1  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 5.11 rather clearly.  By increasing the samples in Figure 5.11, we are able to more realistically represent the way the reflection would look if we had two mirrors facing one another.  In reality, this would reflect forever, and by increasing the number of reflections we are able to make the mirror seem more realistic. Fig. 5.11  Illustration of how increasing reflection depth affects the image

5.7.1.2  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.

5.7.1.3  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 5.12  Reflection/Refraction set to 3/3 Figure 5.13  Reflection/Refraction set to 7/7 Figure 5.14  Reflection/Refraction set to 12/12

5.7.1.4 Auto Cutoff

This value is a percentage used to determine whether further rays need to be cast.  If the next ray to be cast will contribute less than the specified percentage, the ray will not be cast.

5.7.1.5  Max Transparent Intersections

The maximum number of visually overlapping opacity(-mapped) (non-refracting transparency) objects, before they stop affecting one-another; the latest end-opacity result will be used for any other elements behind the overlapping objects.

5.7.2  Options

5.7.2.1  Secondary Effects

This is used to disable or enable all of the Secondary Options listed  below.

5.7.2.2  Raytrace Reflections

This checkbox enables and disables all of the reflection calculations in the scene.

5.7.2.3  Raytrace Refractions

This checkbox enables and disables all of the refraction calculations in the scene.
 

5.7.3  Secondary Effect Options

5.7.3.1  Enable Self Reflect

Turns on or off the ability of an object to appear in its own reflection.

5.7.3.2  Secondary Atmospherics

Turns on or off the ability to reflect or refract atmospherics.

5.7.3.3  Secondary Material IDs

Turns on or off the option to allow Material IDs to reflect or 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.
 

5.7.4  Ray Tracing Acceleration

This is the method Brazil r/s uses to accelerate its raytrace calculations. The null Accelerator is no acceleration.
 

5.7.4.1  Null Acceleration

Not currently available

Fig.  5.14.1  Null Ray Tracing Acceleration Dialog  

5.7.4.1.1  Bounding Boxes

Make use (when checked) of bounding boxes around objects in the acceleration grid setup.

5.7.4.1.2  Bounding Spheres

Make use (when checked) of bounding spheres around objects in the acceleration grid setup.
 

5.7.4.2  Default Ray Tracing Accelerator

Fig. 5.15  Default Ray Tracing Acceleration Rollout

5.7.4.2..1  Space Subdivision

5.7.4.2.1.1  Mode

This allows for the acceleration settings to be implemented in two ways.  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.

5.7.4.2.1.2  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.

5.7.4.2.2  Nested U Grids

The voxel grid is similar to boxes in space that surround pieces of geometry.  Trying to find triangles 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.

5.7.4.2.2.1  Max Size

5.7.4.2.2.2  Max Depth

5.7.4.2.2.3  Max Polys

5.7.4.2.2.4  Balance

5.7.4.2.3  Clusters

5.7.4.2.3.1  Max Clusters

5.7.4.2.3.2  Max Depth

5.7.4.2.3.3  Max Faces (%)

5.7.4.2.3.4  Max Volume (%)

5.7.4.2.4  Hierarchical Bounding Volumes

5.7.4.2.4.1  Mode

5.7.4.2.4.2  Spheres

5.7.4.2.4.3  Boxes

5.7.4.3  High Performance

 This acceleration engine was written for raw pseed, by sacrificing memory. It pre-caches data such as vertices and face-normals, including instanced/references objects (where You would see the biggest memory hit) - data that would otherwise be calculated at rendertime.
 
Fig. 5.15.1  High Performance Ray Tracing Accelerator
 

5.7.4.3.1  Max Size

5.7.4.3.2  Max Depth

5.7.4.3.3  Max Polys

5.7.4.3.4  Balance

5.8  Luma Server Parameters

5.8.1  Direct Illumination

5.8.1.1  Enable

This enables and disables all direct illumination in the scene for all of the selected light types below.

5.8.1.2  Point Lights

When checked, this will allow point lights (omni, spot, direct) to cast direct light onto the objects in the scene.  If this box is not checked, all of your point lights will not affect the lighting of the scene.

5.8.1.3  Area Lights

This enables direct lighting from Brazil’s Area Lights.  Each Area Light has its own settings just as normal Max lights do, which will determine the actual output of the light.

5.8.1.4  Sky Light

When checked, this will allow Brazil’s skylight to cast light directly on all objects.  The skylights settings can be modified in the Sky Light settings of the Luma Server Parameters.
 

5.8.2  Secondary Illumination

Secondary Illumination is used to simulate the nature of light reflecting off of one object and on to other objects, further illuminating the scene.

5.8.2.1  Enable

This enables and disables all direct illumination in the scene for the selected light types.

5.8.2.2  Point Lights

When checked, this will allow point lights (omni, spot, direct) to cast secondary light onto the objects in the scene.  If this box is not checked, all of your point lights will not affect the secondary lighting of the scene.

5.8.2.3  Area Lights

This allows the indirect lighting of Area Lights to contribute to the scene.

5.8.2.4  Sky Light

When checked, this will allow Brazil’s skylight to cast light indirectly on all objects.

5.8.2.5  Allow Caustics

This enables caustics to be projected onto objects in your scene. Currently this only works with geometry lights and the skylight.

5.8.2.6  Volumetrics

Turning this option on will allow volumetrics (atmospherics) to be illuminated by secondary illumination.

5.8.2.7  Toon

Enabling this option will allow any objects with a Brazil Toon Material applied to be effected by secondary illumination.
 

5.8.3  Miscellaneous

5.8.3.1  Shadows

This option turns all scene shadows on and off.

5.8.3.2  Allow Default Lights

Turns the default Max lights on and off.

5.8.3.3  Enhance Bump Shadows

5.8.3.4  Work Lights

 

5.8.4  Sub-Surface Effects

The sub-surface effects are used to simulate light scattering inside of an object.

5.8.4.1  Enable

This checkbox turns on and off the sub-surface calculations.

5.8.4.2  Global Scale

The global scale is used to determine the maximum diameter of an object that will have light passing from one side to the other.  Increasing this value will generally allow more light to pass through objects.

5.8.4.3  Sample Rate

This determines the number if samples used to calculate the sub-surface effects.  Increasing this value will give you a cleaner image, but will increase render times.
 

5.8.5  Global Illumination

5.8.5.1  Shade Rate

5 85.5.1.1  Min

5.8.5.1.2  Max

The Max(imum) Shade Rate controls the maximum number of Global Illumination samples per image sample, behaving, otherwise, the same was as the Miminum Shade Rate.  It is usually unlikely that You would need to have either Minimum or Maximum Shade Rate values over 0. Recommended values for Min and Max, respectively, are : -3,0 (the default) and -2,0, or -4,-1 for preview purposes.
 

5.8.5.1.3  Contrast

The Contrast control determines when the difference between two Global Illumination samples becomes so great, that it would step up a Shade Rate level - until the Max Shade Rate is reached. Lowering the color value will cause the Global Illumination algorithm to adapt sooner, which increases rendertimes, but may provide with a better quality set of samples - especially when used for rendering objects with bump maps. (For a more control over localized Global Illumination shade rates, see the Brazil Utility material's Global Illumination Parameters rollout.)

5.8.5.1.4  Lock to Image Rate

This locks the Min/Max Shade Rate values to that of the Image Sampling rates, including the way that they adapt through the controls, defined in the Image Sampling rollout. This option is not recommended for use, but is provided for possible analysis purposes.

5.8.5.1.5  Show Samples

This checkbox lets You visualize the Global Illumination samples (as single pixels) in a render, using the color specified beside to the checkbox control.

5.8.5.2  Sampling Control

5.8.5.2.1  Sampler

This is the method that Brazil will use to gather the global illumination samples.  The Simple Quasi Monte Carlo Sampler is the currently offered sampler.  It provides the best speed without sacrificing image quality.
 

 Fig. 5.17  Sampling Control Options

5.8.5.2.2  View Rate

This is the sampling rate used by the sampler to generate the global illumination in the scene.  By using a higher sample rate, you will increase the amount of samples generating the lighting.  This leads to a better image, but it also leads to an increase in rendering times.

5.8.5.2.3  Bounces

This determines the number of bounces that a light can make for the secondary lighting.  The more light bounces you have, the more light can reach areas that would normally be in shadow.  This leads to better realism in the image, but the rendering time will increase accordingly.

5.8.5.2.4  Sec Rate

This value determines the sampling rate used by the sampler to generate Global Illumination samples, when the sampling point is seen as reflected/refracted in an object. This usually allows You to get away with lower values - epsecially for reflective, convex, surfaces. Suggested values here are equal to, three-quarters of, and half of, that of the View Rate, although these numbers are arbitrary.

5.8.5.2.5  Depth

N/A at this time.
 

5.8.5.3   Secondary Energy Filters

5.8.5.3.1  Diffuse

The Diffuse Secondary Energy Filter adjusts by how much 'energy' bouncing off of diffuse surfaces should be multiplied. At numerical values over 1.0, energy values increase relative to the standard equation. Set too high, it will cause a blown out image - as no energy loss will occur.  Set too low, and light bounces will seem too dark. Using the color swatch, You can further adjust the 'color' of the energies.

5.8.5.3.2  Specular

As for the Diffuse controls, except for Specular light bounces. These controls are primarily provided as tweaking and special effects tools. Changing their values actually makes the Global Illumination solution deviate from the intrinsic (near-)physical equations.

5.8.5.4  Attenuation

Not available at this time.

5.8.5.5  Secondary Energy Filters

5.8.5.5.1  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.

5.8.5.5.2  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.

5.8.5.6  Sky Light

5.8.5.6.1  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.

5.8.5.6.2  Transparent Shadows

When enabled, the skylight will cast shadows that respect transparency.

5.8.5.5.3  Photon Map Options

not available

5.8.5.7  Shader Degradation

The Shader Degradation controls allow You to 'degrade' objects' shaders (called Materials in 3ds max) to simpler, less CPU-intensive levels, for Global Illumination bounces. This can speed up rendering scenes which use Global Illumination tremendously, since the samplers don't have to evaluate the entire shader hierarchy.

5.8.5.7.1  Mode

Full Shade

This setting (the default) will always have the Global Illumination samplers evaluate the entire shader hierarchy.

Quick Shade

This setting will have the Global Illumination samplers only evaluate the top level of the shader hierarchy (i.e. basic controls such as diffuse color, ambient color, self-illumination etc.)

5.8.5.7.2  Diffuse Map

Used in conjunction with the Quick Shade mode (see above), this will force the sampler to still evaluate the diffuse map of a shader on an object. This option is provided because the diffuse map is usually the part which most profoundly affect a shader's appearance. If You have strong, contrasty diffuse maps on objects, this option should be checked (the default).

5.8.5.7.3  Start Depth

The depth, in number of Global Illumination bounces at which the shaders will start to 'degrade'. The lower the level, the more likely it is that objects will not participate 'correctly' in a Global Illumination solution. The higher the level, the less performance gain You will get from Shader Degradation. Regularly used values are 1 (the default) up to 3. Note that setting this value higher than theGlobal Illumination Bounces value will not result in any performance gain whatsoever.
 

5.10  CSG Server

Fig 5.19 CSG Dialog

5.10.1 Ground Plane

5.10.1.1  Enable

This activates the Constructive Solid Geometry plane. It takes the form of an 'infinite' plane reaching to the horizon. This renders faster than a plane built with polygons.

5.10.1.2  Base Altitude

 Defines the height of the plane on the world Z axis.

5.10.1.3  Base Color

 A colour chip that defines the diffuse colour of the CSG plane.

5.10.1.4  Material

This is the material that will be applied to the CSG plane. Note-  When using explicitly mapped maps, such a bitmap, you should use low tiling settings (e.g. 0.01).