011Rendering

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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

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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.

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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.

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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.

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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.

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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.

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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.

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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