Rendering Notes

Fixed Shader glow now takes into account refraction and reflection properly. I.e., reflections and refractions of shader glow is visible. This implies a slight raytracing performance degradation due to the extra computations.

Fixed Shader glows associated with layered shaders now correctly raytrace.

Fixed Light glow outside the filmback will now properly render.

Fixed Activating the depth map output will no longer screw up the depth of field rendered image.

Batch Renders (Renderer and Raytracer)

Limitation

When rendering on fields, the sense of determining which scanline is odd, and which is even can be confusing, and may not produce the results you want.

If the timing of the setup is incorrect, you can reverse the odd/even scanlines by typing:



setenv ALIAS_SWITCH_SCANLINES_EVEN_ODD_SENSE

Alias begins numbering scanlines from the bottom of the image starting with scanline 0 (an even scanline) which makes the top scanline odd (485 for NTSC). Setting the environment variable makes Alias treat the top scanline as an even scanline, effectively numbering the scanlines to start from the top of the image. Note that if Composer is to be used for interlacing fields, the above environment has to be turned on.

Limitation

Extension Padding is set to 3 when retrieving and rendering previous version wirefiles.

If an older wirefile (Version 6.1 to Version 7.0.1) is retrieved, ensure that the Extension Padding value in the Animated Output Filename Extensions is set to 3 in the Render Globals window. This results in rendered frame names appearing as filename.001, filename.002, etc.

Workaround

Retrieve the wirefile, set the Extension Padding value to 1 in the Render Globals window, then select File > Save As and work with the file as a current wirefile.

Limitation

The renderer attempts to render invisible objects with blended surfaces fail.

Workaround

When a part of the blended surface is invisible and another part is visible, it cannot render because there is missing information (the invisible objects are not written to the SDL file and thus the blend cannot be regenerated for each frame). Remember to make all portions of a blended surface visible.

Limitation

Multiple instances of the same polyset with linked-lights and multiple shaders may result in a crash of the renderer.

Workaround

Avoid instancing such polysets (with linked-lights and multiple shaders). Copy the polysets instead.

Limitation

The geometry in the Perspective window looks different than the rendered image when the camera has motion path curves with knot multiplicity.

Workaround

Motion path curves with multiplicity can cause this problem. Rebuild the curve or select Curve Tools > Use result in the Action window.

Limitation

When using Raycast and Raytrace, invisible instances render when they should not.

When an object is copied and Instance is toggled on in the Duplicate Objects Options box (Edit > Duplicate object-) with a translation of some kind so that the instances are shown separately from the originals, and the "instance" object is picked in the SBD window, made invisible, and QuickRender is run, only the real objects render. When Raycast is run, the invisible instances render as well.

Workaround

When adjusting or animating visibility, make copies instead of instances in order for the batch renderers to work properly.

Limitation

The camera presets' pixel squeeze ratio is ignored by the batch renderer.

Workaround

If you want to produce an anamorphic image, use the following work flow.

1: Retrieve a model.

2: Using Render > Globals, set the resolution to something appropriate for your anamorphic lens (for example 500, 423).

3: Still using Render > Globals, set the pixel aspect ratio to something appropriate for your anamorphic lens (for example 2.0).

Note:

The pixel aspect ratio is used as a substitute for the anamorphic squeeze ratio.

4: Using the Camera Editor (Windows > Camera editor), set the filmback to the format of your choice (there some predefined filmbacks meant for anamorphic lenses).

5: Render it.

If you would like to view it undistorted:

1: Using Render > Filter > Resize, make a new pix file from the rendered one with the Y dimension the same and the X dimension multiplied by whatever pixel aspect ratio you used (in this case 1000, 423).

2: View both the original and resized pix files to see the effect.

Limitation

With depth of field, the edge of an object in focus against a very blurry foreground or background sometimes shows a jaggy artifact.

Workaround

Render foreground blurry elements separately and composite.

Limitation

Banding may appear on low intensity objects.

Workaround

Due to the 8-bit per color channel limitation, it is possible to see banding in the rendering. This can be eliminated by turning on film_grain by setting the value to 0.01, or altering the colors of the lights by random, fractional amounts from pure integer values (for instance, (255, 255, 255) becomes (254.3, 255.2, 254.9)).

Limitation

Remote rendering does not copy back the images produced until the entire rendering sequence is completed.

Workaround

Render in smaller sequences if disk space is limited on the remote machine.

Limitation

When writing to SDL, comments are no longer available.

This is done to reduce the disk usage of SDL files. If you want comments, put the following line in your shell before starting Alias in order to have the comments written out:



setenv ALIAS_SDL_LONGFORM 1

Limitation

Use background color is not taking lighting into account.

Since Version 6, lighting is ignored and the background is assumed to have the correct intensity already.

Workaround

If you want a shader to take lighting into account, set the following environment variable before running Alias or the renderer:



setenv ALIAS_V5_USE_BACKGROUND 1

Limitation

Templated objects rendered in an animated sequence may become visible.

Glows/Fog/Special Effects

Limitation

Glow and particles do not QuickRender in the Perspective magnify window.

Limitation

A partial QuickRender will ignore shader glow.

If Persistence is toggled on for QuickRender and a partial (subregion) QuickRender is done, that partial region ignores shader glow.

Workaround

Click on the QuickRender window to render the entire window.

Limitation

Light glows will not Quick Render in orthographic cameras.

Workaround

You can render light glows only with the batch renderers, but not with Quick Render.

Limitation

Glow appears to be missing from a volume light source.

Missing glow is most likely to occur with volume lights, and is due to the physical nature of light glows. A Volume light has a boundary beyond which light does not extend. If no light reaches the eye, then no light glow is rendered.

Workaround

If a light glow from volume lights is required, ensure that the light boundary extends past the camera eye point (use Display > Tgl camera to ensure the camera is inside the light volume), or create a glow-only point light at the same position as the volume light.

Limitation

Shader glow flickers during an animation. As well, shader glows look different at different resolutions.

Workaround

Shader glow flicker is due to the auto-exposure option for shader glows. Auto-exposure computes the maximum intensity of the shading and produces a normalization for the glow. Thus if the maximum intensity differs from frame-to- frame (as it will if glowing objects come in and out of frame), the glow changes intensity as well.

There are two workarounds:

Select Windows > Multi-lister > Shaders. Double-click on the Environment shader, then turn Shader Glow > Auto Exposure OFF. Then adjust the glow intensities by hand.

: or...

Choose a frame in which the glow looks best, then run the renderer with auto-exposure ON. In the out file, find the information about "intensity normalization factor". These are the exact values for the glow intensities. Turn auto-exposure OFF and enter these values into the text boxes.

: You can also use this trick to get the same glow at different resolutions. The glow looks different due mainly to the auto-exposure. Use the above procedure, but instead of entering the glow intensity from the out file, divide the intensity by the square of the factor by which you want to increase the resolution:

For example: you render the glow you want with auto-exposure, and in the out file you see that the glow intensity was 8. If you want to double the resolution, enter a glow intensity of 2:

Limitation

Linear and area light glows shine through objects.

These lights do not attempt to detect if there are shadowing objects between the light and the eye. All other light types compute this occlusion factor.

Workaround

Create a shader glow object of the same shape as the light with Hide glow source ON.

Limitation

Light glow occlusion can be incorrectly computed (that is, light glow shines through objects) if the glow opacity is set to any value other than 0.

Workaround

This problem occurs in both the raycaster and raytracer. The best solution is to set the glow opacity to 0 on the occluding object.

Limitation

Light glow appears to dim but not fully disappear when going behind an object.

This problem occurs due to the radius of the light - it may be so large that it is never completely occluded by the object that should be shadowing it.

Workaround

Open the light editor for the light in question. Access the light radius parameter under Common Parameters. The default radius is 1.0, which means the light is two grid units in diameter. If this diameter is large in relationship to the geometry in the scene, reduce the radius to something more appropriate to the size of the geometry occluding the light (for example, 0.1), then test render again. The glow should now be more fully shadowed.

Particle Systems

Limitation

Rendering particles may not produce consistent results if animation is set to OFF.

Workaround

Sometimes particle rendering is different depending on whether or not Animation is set to ON in the Render Globals window. Set Animation to ON to produce the correct results. Using particle files may also alleviate this problem.

Limitation

Shell objects, stitched objects, and faces do not emit particles. Polysets do emit particles, but do not do so correctly unless the polygons are convex.

Limitation

Rendering opaque blobbies (Render type blobby surface) with light fog may show some artifacts.

Workaround

To correct this problem, before launching the renderer, type the following from the console window:



setenv ALIAS_LIGHTFOG_BLOBBY

Limitation

Rendering of particles may take a little longer than with versions prior to v8.5.

Workaround

Previous versions relied on the amount of memory to determine the rate of particle emission. Unfortunately, this approach will then result in different renderings on machines with different memory configurations.

Limitation

Particles are not calculated if the surface generating them is invisible on the startframe of rendering.

Workaround

Animate the transparency factor instead of the visibility flag, or create particle files from the visible geometry in the interactive package.

Limitation

Parent color set to ON seems to have no effect on particle color.

Workaround

If Parent Color is set to ON, particles are born with the color of the parent surface at the point of emission. In order to see the effect of changing this flag, you will have to re-emit the particles.

If parent color was animated on and off during particle emission, then the color of emitted particles will alternate accordingly (as opposed to the entire particle system suddenly changing color).

Modifying any Emission or Behavior parameters on the particle system requires that you run the simulation to see the effect (or invoke a batch render, which does its own run of the simulation). Also note that if particle files are used, changing any of these parameters will have no effect, as the particle trajectories and birth color are defined in the files.

Limitation

Particles that overlap transparent surfaces can sometimes make the surface partly visible, even though it is completely transparent.

This can happen if there is blob noise on the particles, or if the Render Type is BLOBBY SURFACE.

Workaround

When blob noise is a problem, the effect is generally much less noticeable in the raycaster than in the raytracer. If the transparent surface is used to emit the particles, then a possible solution is to create particle files and then move the transparent surface out of view. If the hidden surface does not emit particles, then you can simply animate its visibility.

Limitation

Particles do not recompute over each odd and even field, only on each frame.

This should not produce any clearly visible unwanted artifacts.

Limitation

Changing transparency may seem to have no effect when a BLOBBY SURFACE render method is used on very large or very small particles.

Workaround

It actually does; however, the transparency is based on the depth of the blobby substance in world units. To correct this, you can set the density parameter to be 1.0/particle_size. So if your particle size is 0.1, then making the density 10 should allow the transparency slider to have a normal range of effect.

Limitation

Image planes and sometimes transparent objects do not render correctly when combined with fog and/or particle systems. This has been improved since Version 7.0.1, but artifacts remain.

Limitation

Mapping textures to particle parameters doesn't update properly.

If you map a texture to a parameter in the particle emissions section of a shader or light and change the texture's parameters, the texture's icon won't update.

Limitation

Particle color map influenced by particle color.

If you want particles to derive their color from the surface that emits them, make sure Parent Color is ON.

However, the blob's own color acts as a multiplier. If you want the blob to use the parent color exactly, the blob's color must be white.

Note:

This is not documented, is not indicated in any way in the interface, and is inconsistent with how texture colors are usually specified.

Limitation

Particles can only emit from original, non-displaced surfaces.

If there is a surface which has a displacement map, the particles emit from the surface in its original non-displaced position.

Limitation

Particles may disappear when surface-shading is set to a non-zero value and particles originate at the camera origin.

Limitation

Particles colliding with NURBS surfaces that have geometry collisions enabled may cause a rendering error when motion blur is requested.

Workaround

Write and use particle files for the colliding particle systems, and then turn collisions off for both the NURBS surface and the particle system before rendering.

Light Warps

Limitation

Unable to pick a warped object with a small marquee region.

Workaround

Picking warps may require a larger marquee pick region. This is because the surface's bounding box is unwarped.

Limitation

Surfaces that have both warps and displacement maps can result in unexpected behavior.

Limitation

Light warps do not render properly with degree 1 patches along the patch edges.

Workaround

Degree 1 patches are often generated from the Surfaces > Set planar-

function when Trim Surface is selected in the option box. Instead of using this option, create a degree 3 plane, project the outline curves onto the geometry and trim the result.

Limitation

It is possible to create warps for which no amount of triangulation can smooth the surface.

This happens when a warp is created with sudden discontinuities in its field, and these sudden discontinuities overlap a surface.

For example, the twist warp preset (Objects > Warps > Twist) pushes a surface the most at the edges of the cylinder, however just beyond the edge of the cylinder, the warp is zero. A surface intersecting the edge will go from no warp to maximum warp across the span of a single triangle.

The decay and dropoff parameters can be modified to smooth out these transitions.When these parameters are insufficient to smooth a field, smooth gradients can be created by texturing the light's color (which affects the warp intensity).

Motion Blur

Limitation

When rendering with motion blur, some artifacts may result in either the disappearance of triangles, or grid-like artifacts. This is due to some large triangles that extend beyond the camera and near clipping planes.

Workaround

Identify the trouble surface(s) and increase the tessellation subdivision level. Objects that are very close together may also cause interpenetrating problems for motion blur. Cheat by moving the surfaces further apart in these cases.

Limitation

Motion blur is not implemented for raytracing.

Limitation

Shadows and light positions do not motion blur.

Limitation

Shadowing appears jittered on motion blurred objects moving away from the camera.

Workaround

Increase the Shadow's Min Depth for shadow casting spotlights, or turn shadow casting off on the front portion of the object if the object has a separate back face and does not self-shadow. Shadows are not motion blurred, so the shadow depth stored is at the depth of the object at the shutter mid time. This means some of the shading samples will find themselves to be in shadow while others will still be illuminated. If this still does not solve the problem, edit the SDL and add the following to the spotlight casting the bad shadows:



use_old_shadow_map_algorithm = FALSE

Limitation

Motion blur is not applied when warp parameters are animated.

When a parameter on a warp is animated, the resulting changes in the shape of the object are not motion blurred, although an object moving through a warp will be motion blurred correctly.

Workaround

Move the object relative to the warp light.

Texture Mapping

Limitation

Displacement mapping does not work for layered shaders.

A displacement map on only the lowest available layered shader is applied.

Workaround

Paint a displacement map with only the important areas and apply that map to the lowest layered shader.

Limitation

Multi-lister chord length texture mapping doesn't display correctly in shadewire.

If a surface with uneven parameterization and a checker texture map with Chord length ON is Quick rendered, the texture looks even, as a result of the chord space conversion. However, if the Quick render window is closed, and the shaded wire icon in the icon of the texture is clicked on, the surface is displayed as though Chord spacing is OFF.

Limitation

Instancing of objects with worldspace texture mapping enabled can produce incorrect rendering results.

Workaround

Copy the geometry rather than instance it.

Limitation

Using BOT files directly as texture maps may result in the renderer saying it does not recognize this format.

Workaround

Turn Render > Globals > Memory Options > Texture Caching on.

Tgl Shade

Limitation

Black dots appear on textured objects in toggle shade on an Indigo 2X.

Workaround

When running with fast-options off and texture mapping turned on, it is possible to see little black dots on the texture when the subdivided triangles are very small. In these cases, try reducing the subdivision level of the problem surfaces.

Limitation

Colored texture maps in RRFR and Toggle shade with Int Off and Fast Off may be inaccurate.

Workaround

Turn textures on in the QuickRender options window.

Limitation

Toggle shade does not respect volume lights.

Volume lights are treated as point lights when viewed in toggle shade mode. Therefore, interactive manipulation is not possible.

Limitation

If QuickRender's texture flag is turned off, texture maps may not render when toggle shading

Workaround

Reset the QuickRender's texture flag and do a QuickRender (setting the texture flag alone won't solve the problem), then toggle shade will render correctly with textures.

RRFR (ReallyReallyFastRender)

Limitation

The current Fast Render does not load Version 7.0 RRFR files properly.

Limitation

When updating RRFR from the interactive package, the camera view will also be updated in RRFR.

Multi-Lister

Limitation

Super textures (including Studio Paint 3D textures) don't display on shader balls.

Workaround

It is necessary to be able to distinguish a regular textured item versus a super-texture. Currently, the super-texture swatch does not display the list of associated textures, but it does display an icon that appears very much like a layering of a stack of papers. This is an important indicator for super- texture feedback.

Limitation

Can't get lateral movement in numerical fields.

Workaround

The Alt key has to be pressed when this lateral movement is required.

Limitation

When viewing the Multi-lister with lower resolution swatches, the icons are not displayed.

Workaround

Switch to the higher resolution swatches.

AliasToRenderman

Limitation

AliasToRenderman generates RIB output which references two custom shaders, ari_pointlight and ari_spotlight.

The Shading Language source for these shaders is provided in the gifts shaders. These shaders are identical to the corresponding published standard shaders in all respects except for one extra parameter - light decay.

These versions allow light decay in the same form as the Alias Studio lights, and are provided as a convenience. However, to use them for rendering, they must be compiled using a RenderMan Shading Language compiler that goes with your RenderMan Renderer, and also, the result must be placed in your file system where the renderer can find it.

That setup may be inconvenient, so a command line override was provided for the AliasToRenderman standalone. The option is -d , and it takes an argument.

If the argument is 0 (zero, the default), the Alias shader names are generated.

If the argument is any other value, then the standard "pointlight " or "spotlight " names are generated.

Note: The -H help message includes -d <d>.

If <d> is zero, "Alias " shaders will be used where possible, or only RenderMan standard shaders will be used.

Flipbook

Limitation

Flipbook does not handle mask files.

Workaround

The fcheck utility supplied in the common bin/ directory will display sequences of mask files.

Limitation

Flipbook does not support negative file extensions for animations.

Animation files can be created with negative file extensions and rendered, but they cannot be viewed in the flipbook.

Workaround

Always use positive integers for file extensions.

Miscellaneous

Limitation

If you start multiple Power Renders on the same MP machine, you might get the message "/usr/temp/sgi_mp_rt_locks permission denied"

Workaround

Use the following command to fix the problem:



setenv ALIAS_PLACE_LOCKS_IN_SWAP

Limitation

File > Show pix from the main pull-down menu cannot display multiple files.

Workaround

Use File > Show pix in the File Browser to show multiple pix files.

Limitation

Shaded Wire only displays correctly for NURBS and faces. It currently does not deal with polysets correctly.

Limitation

It is not possible to WRL a TIFF image while rendering. TIFF images can be displayed only after the image is completed.

Limitation

It is not possible to directly use compressed images (for example, filename.Z) unless the image is in the Alias PIX format. For other image formats, the files will need to be uncompressed first.

Limitation

The Display > Tgl Render Status status bar is unaffected when moving Alias window.

Resizing, stowing, or moving the Alias main window will not affect the toggle render status bar. If you stow or minimize the Alias main window using an X-window stow or minimize, the render status bar will stay up.

Workaround

Use Utilities > Minimize to minimize the Alias window.

Limitation

If you use Delete> Active from the main menu to delete multiple projection nodes associated with the same shader at the same time, Alias may crash.

Workaround

Use the Multi-lister to delete the shader or texture associated with the projection.

What is Needed to Run the Optimized Renderers on IRIX 6

In order to use the renderers you must first install certain system libraries onto your system. To see whether you have the libraries, type this command in a shell window:



showprods compiler_eoe.sw32 c_eoe.sw32 c++_eoe.sw32

If you have the libraries installed you should see output like the following (I = Installed, R = Removed):

Name Date Description

I c++_eoe 10/01/96 Standard Execution Environment (C++, 6.2)

I c++_eoe.sw32 10/01/96 Standard Execution Software (N32bit)

I c++_eoe.sw32.lib 10/01/96 Standard Execution Libraries (N32)

I c_eoe 10/01/96 Standard Execution Environment (C, 6.2)

I c_eoe.sw32 10/01/96 Standard Execution Software (N32bit)

I c_eoe.sw32.lib 10/01/96 Standard Execution Libraries (N32)

I compiler_eoe 10/03/96 IRIX Standard Execution Environment, (Compiler, 6.2)

I compiler_eoe.sw32 10/03/96 IRIX Standard Execution Environment Software (N32)

I compiler_eoe.sw32.lib 10/03/96 Base Execution Libraries (N32)

I compiler_eoe.sw32.unix 03/18/96 IRIX Execution Environment (N32)

If you don't see any output or some subsystems are missing then you must install the libraries from your IRIX 6.2 operating system CDs. They are on the CD labelled `IRIX 6.2 (Part 1 of 2)'.

If you're using Software Manager, the libraries you need to install are part of "Standard Execution Environment (C++, 6.2)", "Standard Execution Environment (C, 6.2)", and "IRIX Standard Execution Environment, (Compiler, 6.2)". In the first two products you want to install the "Standard Execution Libraries (N32)" subsystem. In the last product you want to install "Base Execution Libraries (N32)".

If you're using inst then the short product names of these subsystems are c++_eoe.sw32.lib, c_eoe.sw32.lib, and compiler_eoe.sw32.lib. For more information on installing software see the IRIS Software Installation Guide.

Tips and Tricks for the Anti-Aliasing Definition

Anti-aliasing definition change

The definition for the anti-aliasing parameters changed as of Version 7.5, and continues to apply. The min and max values now indicate the number of samples to be taken per pixel, rather than a level, as in previous versions. The approximate mapping between a Version 7 anti-aliasing value X to Version 7.5 would be X². The recommended quality settings are now:



low quality - (min,max) = (0,0)




medium quality = (0,4)




high quality = (3,12)

What is Aliasing?

The most commonly recognized features of aliasing include:

jaggies or roping

noisy or jittered images

shimmer or moiré-banding seen over an animation

Though the above artifacts are all due to aliasing, not all aliasing artifacts are caused by the same limitations, nor are they resolved in the same manner (for example, bumping up the Minimum and Maximum Anti-aliasing Level values in the Render Globals window will not solve your problems optimally). The following is a complete list of causes of aliasing artifacts and tips on how to improve the image quality without increasing the performance costs globally.

Note:

One thing to be aware of is that in one particular situation, the images produced are intentionally aliased. This occurs when composite rendering is turned on. You should check for this, as this might be your only problem. This option does not account for the background, thus the images (as they are) look aliased, but compositing the rendered result with something else will produce perfectly anti-aliased images.

Tips

Geometry edge aliasing

: This is when geometry shows jagged edges. The only way to improve the quality of this artifact is to increase the values in Render > Globals > Anti-aliasing levels. Increase the Threshold value first and, if the jagged edges persist, then increase the Minimum and Maximum values.

File texture aliasing

: If file textures are very noisy and the anti-aliased results are not good, or if they appear to shift or shimmer over an animation, the first thing to check is that the texture's blurmult is non-zero. The next thing to try is to change the Filter type in the file texture's editor. The default is BLEND. The best compromise of speed versus quality is QUADRATIC.

Procedural texture aliasing

: If procedural textures are very noisy, and appear to shift or shimmer over an animation, you can try the following:

increase the blurmult and/or bluroffset values, so it can be slightly blurred to avoid the shimmering.

increase the value in Render > Globals > Anti-aliasing levels > Threshold.

use the Convert to Pix feature (in the Effects section of the texture editor window, which is accessed by clicking on the texture in the Multi-lister), so that a file texture is produced, then change the Filter Type to QUADRATIC.

Raycast shadow aliasing

: The shadows produced from shadow casting can result in jagged shadow boundaries. This is mostly due to the resolution of the shadow map. You should try to:

narrow the spread of the spotlight so that it snugly covers the region you want to light. This provides a higher accuracy to the shadow map to work from. If you see banding artifacts, try increasing the Min Depth in the Self Shadow Correction section of the Light editor for the light's shadow.

increase the resolution of the shadow map as a final resort. Remember, though, that keeping large shadow maps does increase memory usage.

Light fog shadow aliasing

: The shadows from light fog may appear incorrect when very skinny objects are missed. This can appear as light fog shadows shifting over an animation. The only way to resolve this is to increase the fog samples in the light.

Raytrace soft shadow aliasing

: The soft shadows produced by raytracing can produce noisy and jittery effects. You can try the following in the Ray Tracer Soft Shadows section of the Light editor if this occurs:

if it is a spotlight, toggle Use Shadow Map to ON so that the raycast shadows are used.

increase the number of Shadow Samples.

Skinny specular highlight roping/aliasing

: Sometimes, skinny highlights can exhibit roping artifacts. This might be due to the hard-edged highlights that the standard Phong model produces (many times magnified by a noisy bump map). In this case, it is best to use the Blinn shading model instead. You might also try turning the Post Filter option ON in the Blur Effects section of the Render Globals window when this problem occurs.

Motion blur aliasing

: If motion blur results in some noise, it is usually because of the insufficiency of temporal sampling of shading and/ or textures. The best choice is to open the Render Stats window (Windows > Information > Render stats) and increase the texture sampling rate of the object exhibiting artifacts if the texture looks grainy - or - increase the shading sampling rate if the specular looks noisy.

Note:

Increasing the texture sampling rate will marginally increase rendering time, and increasing the shading sampling rate will noticeably increase rendering time, so it is recommended that you only increase shading sampling when absolutely required.

Please send questions or comments regarding the documentation to:

[email protected]