011rendering
DESCRIPTION
Objective Rendering is generally the final stage in preparing a presentation for a client. Once all the work has gone into creating a design in a 3D program, rendering the design provides you with images or animation which you can easily transfer to the client. 365 Render your designs to fixed images or animations After completing this chapter, you will be able to: ITRANSCRIPT
365
Chapter
11
RenderingChapter 11:
Rendering is generally the final stage in preparing a presentation for a client. Once all the work
has gone into creating a design in a 3D program, rendering the design provides you with images
or animation which you can easily transfer to the client.
Objective
After completing this chapter, you will be able to:
n Render your designs to fixed images or animations
366 n Chapter 11: Rendering
Lesson: Rendering
Overview
Rendering is typically the final stage of the 3D process. It is certainly the last thing you do when you
want to show the final product to a client. The final product can be an architectural rendering, the
latest design for a game box, a simple Web-based animation, or even a feature film. The final rendering
takes into account all other aspects of the production pipeline, including modeling, texturing, rigging,
lighting, and animating.
Objectives
After completing this lesson, you will be able to:
n Work with the Render Frame Window to create renderings of your scenes
n Use the Render Setup dialog
n Use Batch Render to automate the rendering process
Lesson: Rendering n 367
Render Frame Window
The Render Frame Window brings many of the most used rendering settings together into a
single dialog.
A: Rendering Controls Area – In this area you have several tools to control the rendered output.
B: Rendered Frame Window toolbar – This area is primarily used to control the display and output
of a rendered frame.
C: The Rendered Image.
D: mental ray Rendering Options – Settings for the mental ray renderer including Final Gather, Soft
Shadows, Reflections, Refractions are controlled here. This area only appears when the mental ray
renderer is active. If it does not appear you will need to set the renderer in the Render Setup Dialog.
368 n Chapter 11: Rendering
Render Window Controls Area
At the top of the Render Frame Window is the Controls Area, it contains controls for the Area to
Render, Viewport, and Presets.
Render Frame Window Toolbar
Just above the rendered image is the Render Frame Toolbar. Of primary interest in this area are the
image display and output controls.
The Area to Render tool of the Controls Area is ideal when you are doing test renders of your scene.
Here you can control the renderer to just render selected areas or objects. Rendering smaller areas
or selected objects reduces time spent on rendering, speeding up the trial and error process.
The Viewport Control allows you to select a viewport to render directly in the Render Frame Window.
More importantly, combined with the lock button to the right of the pull down list, you can lock the
viewport to be rendered. This avoids the problem of rendering the wrong viewport while you are
working on the scene.
The right part of this area contains a few items of note at this point. The two buttons on this left of
the illustration provide access to dialogs which allow you to further establish settings, Render Setup
and the Environment and Effects Dialogs. These are described in more detail elsewhere. Lastly, when
you are ready to render your scene, the Render button is at the top right of this area.
To the Left of the toolbar are image output controls, where you save, copy to the clipboard, clone to
a window, print and clear the rendered image in the Render Frame Window. To the center of the
toolbar are image display controls. Typically set to RGB display the image can be toggled to display
the Alpha channel, or as a monochrome image.
Lesson: Rendering n 369
mental ray Rendering Options
At the bottom of the Rendered Frame Window is the mental ray Rendering Options area. The controls
in this area will affect the speed of rendering and the overall quality of the image.
On the left side of the mental ray Rendering Options area are toggles and settings which will affect
image quality and render times.
Reflections and Refractions, are for shiny and/or transparent surfaces. Often this can be the source of
slow render times. If you are doing test renders for materials which have little or no shininess or
transparency you can turn reflections and refractions off, or turn down the default maximum values
from 4 reflections to 2, and 6 refractions to 3. This will speed up your test renders. Should you notice
black patches in reflective or glass surfaces this is due to those values being too low.
Soft Shadows are generated from light sources which have a form other than a simple point.
Unfortunately the calculations involved in generating these soft shadows take longer to compute.
While doing test renders it is generally a good idea to turn off generating soft shadows.
Final Gather is a setting to control one method of indirect illumination. When Final Gather is on you
will see the effect of the mr sky, ambient occlusion as well as light bouncing in the scene. How much
the light bounces in the scene is controlled by the Bounces setting. Generally 2 to 3 bounces is
considered a practical maximum for most scenes.
In the Reuse area you can enable reuse of computations which the mental ray renderer performs.
mental ray goes through 2 passes to calculate the geometry and final gathering of light before
performing its final render pass. Should the scene’s geometry have not changed, you can enable
the reuse of the geometry calculation. If the lighting has not changed you can enable the reuse of
final gather.
370 n Chapter 11: Rendering
Render Setup Dialog
You set the parameters for rendering on the Render Setup dialog. The keyboard shortcut to open
this dialog is F10. You can also click the Render Setup button on the main toolbar or in the
Rendered Frame Window.
In the precision control area you can use the 2 sliders to adjust preset values for the image rendering,
and for the final gather calculation. When rendering in mental ray there are two very noticeable
passes that the renderer performs. The first being the final gather pass and the second the final
rendering pass. The Image precision slider will affect the speed of the final rendering or 2nd pass.
A low value is generally tolerable, medium is usually acceptable, and high is generally the most you
would need to set this slider to. For Final Gather, draft precision works very well in exterior or simple
lighting schemes. More complex lighting setups, for example an interior scene or where there is a
requirement for the scene to be lit from light that has bounced repeatedly, may require a higher or
a custom setting.
The Render Setup dialog has multiple panels, accessed from tabs at the top of the dialog. The
number of panels and their names can change, depending on the active renderer.
Lesson: Rendering n 371
Common Panel
The Render Setup dialog’s Common panel contains controls that apply to all renderers. The Common
panel contains four rollouts; this section focuses on the Common Parameters rollout.
372 n Chapter 11: Rendering
Time Output
The Time Output group lets you specify which frames to render and whether to generate an animation
(such as an AVI file), sequential single-frame output, or a combination of different frames that are not
sequential.
Output Size
The Output Size drop-down list lets you choose from a number of standard film and video resolutions
and aspect ratios. Choose one of these formats, or use the Custom choice to specify your own settings.
35mm Anamorphic (2.35:1)
Custom (640x800)
Lesson: Rendering n 373
Render Output
Another important part of the common parameters rollout is the Render Output group. This is where
you can save the output files to disk when you’re done.
The Render Output group and its parameters.
Click the Files button to specify the output filename and image type.
If you attempt to render a sequence of frames, you first need to specify the base file name and image
format or you’ll be prompted by a warning.
374 n Chapter 11: Rendering
File Type
Batch Render
The Batch Render tool offers you a more efficient and visual approach to setting up tasks when you
want to render without having to be in front of the computer. With Batch Render, you can render all
your scene states at once, and you can also render from different points of view based on different
cameras in the scene.
The Batch Renderer is available from the Rendering Menu.
When you render a scene, you can output a still image or an animation. You can output to most of
the known formats, such as JPG, TGA, TIF, and many others. Movie file types include AVI and
QuickTime. Some of the formats support various options. If output options are available, these
appear in a separate dialog. In the Help reference, file options are explained along with the
description of the image file’s format.
Lesson: Rendering n 375
Exercise: Output Size
In this exercise, you work with the Render Settings
dialog to change the output size.
1. Open the file Boat_model_Size.max.
A summer day at sea
2. Click on the Render Frame Window Icon on
the Main toolbar.
3. In the Render Frame Window click on the
Render Setup icon to open the Render Setup
dialog.
4. Make sure the Common panel is active and
that the Common Parameters rollout is
expanded.
Examine the Output Size group.
5. From the Output Size drop-down list, choose
35mm Anamorphic (2.35:1).
6. Minimize the Render Setup dialog and the
Render Frame Window.
7. Right-click the Camera01 label in the viewport
and choose Show Safe Frame.
376 n Chapter 11: Rendering
This allows you to view the camera’s aspect
ratio in the viewport.
Using Safe Frame is important when framing
a shot; it can help you optimize image
composition.
8. Restore the Render Frame Window and click
Render to see the rendered image.
Lesson: Rendering n 377
Exercise: Batch Render
The Batch Render tool offers you a more efficient and
visual approach to setting up tasks when you want to
render without having to be in front of the computer.
With Batch Render, you can render all your scene
states at once, and you can also render from different
points of view based on different cameras in the
scene.
1. Open the file Boat_Batch_Render.max.
2. From the Rendering menu, choose Batch
Render.
3. Click the Add button.
4. In the Name field, change the existing name
to Daytime. Be sure to press ENTER after
typing the name.
5. From the Camera and Scene State drop-down
lists, choose Camera01 and Daytime,
respectively.
6. Click on the Output Path button.
7. Set an output path and name the output file
Boat_Daytime.jpg.
8. Add a second batch render job and name it
Nighttime.
9. Set Camera to Camera01 and Scene State to
Nighttime.
378 n Chapter 11: Rendering
10. Set an output path and name the output file
Boat_Nighttime.jpg.
11. Click Render.
Batch Render takes over rendering the scene
based on the two states that you set up. The
rendering is accomplished without any need
for intervention on your part.
Chapter Summary n 379
Summary
Having completed this lesson, you can:
n Work with the Render Frame Window to create renderings of your scenes
n Use the Render Setup dialog
n Use Batch Render to automate the rendering process
Chapter Summary
Having completed this chapter, you can:
n Render your designs to fixed images or animations