Global Supersampling

Supersampling is an additional anti-aliasing pass completed at render time to smooth out inconsistencies in the anti-aliasing. It is not calculated at all if anti-aliasing is turned off. With supersampling off, the center of the area represented by the pixel determines the color of the pixel, which can result in jagged aliasing. With supersampling on, the area in and around the pixel is sampled at a certain rate to calculate the pixel color that will best reduce aliasing in the area.

As we discussed in Chapter 9, you choose a supersampler and enable it in the SuperSampling rollout of a material. The Disable All Samplers check box in the Global SuperSampling section of the Render dialog turns off supersampling in all materials. You want to be able to turn them off for test renders to speed up your render; having supersampling on can drastically increase render time.

Color Range Limiting

Color Range Limiting prevents colors from being too bright and “blowing out” due to the additive properties of the different color attributes. It also prevents the less common problem of colors being out of range in a negative direction. There are two options: Clamp and Scale. Clamp cuts off any values that fall out of range. In this method, colors that are too bright might wash out or become white. Scale retains the hue information but scales the RGB values up or down to comply with the ranges. This can cause your Specular highlights to look odd. (It’s better to adjust your lighting to avoid out-of-range colors, if possible.)

Object Motion Blur

Object motion blur is the simulation of blur without actually blurring pixels. It is set per object in Object Properties. When object motion blur is applied globally (by checking Apply), MAX renders the object at a sub-frame sampling rate (up to 16 per frame) and offsets the images in the direction the object is moving. This leaves a “trail” of images. Duration Subdivision is how many time intervals the frame is broken into; Samples is the number of these intervals that are sampled. For a very even trail, the Samples value should equal the Duration Subdivision value. For a coarser, more randomized trail, set Samples less than Duration Subdivision. Duration is the number of frames the image is held for. Like so many render options, object motion blur substantially increases render time.

Image Motion Blur

Like object motion blur, image motion blur is also assigned to objects in Object Properties. If Apply is unchecked in the Render dialog box, the motion blur will not be applied. Image motion blur blurs the pixels rather than superimposing a series of images. It is a post-process blur added after the regular render pass. Duration sets the length of the blur. Apply to Environment Map will blur the background when the camera moves. Image motion blur will not work with objects whose geometry changes over time, nor those with displacement maps.

	TIP Image motion blur is generally preferable to object motion blur, creating an effect more similar to an actual camera motion blur.

Auto Reflect/Refract Maps

This setting controls the quality of auto reflection/refraction maps. A higher number will definitely give you a better reflection; it will also significantly increase render time.

Network Rendering

MAX’s network rendering is one of the most powerful features of the program, because with one license of MAX, you are permitted unrestricted multi-machine rendering at no extra cost.

	TIP If you don’t have a network of computers available and you desperately need to speed up your rendering process, you might want to consider using a commercial render farm. They can network-render your job on hundreds of machines. Depending on your budget and your deadline constraints, it may be worth the expense.

Network rendering uses the manager/server principal. One machine is the manager; it takes control of the job and doles out work to other machines called servers. Servers are the workhorses; they communicate with the manager and do its bidding. (Don’t let MAX’s terminology confuse you if you’re used to “client–server” systems. What is usually called a “server”—the central machine directing others—is a “manager” in MAX; the usual “client” is, in MAX, a “server”.) Manager.exe and Server.exe are executables that are automatically installed when you install MAX. They are located in the \3DStudio Max 3 root directory.

	TIP AVI, FLI, or QuickTime movies can only be rendered on one machine. You can send them to a server machine to be rendered, but the frames are not divided up among the other machines. You need to render a series of single frames to take into Video Post or a compositing program.

Setting Up Your Network

Before you can network render, your network setup must meet the following conditions:

•  Your machines must be on a stable Windows NT network. Network rendering is only supported in Windows NT.

•  You must have administrator privileges.

•  Although only one hardware lock is needed, MAX must be installed and authorized on all the machines.

•  You must know the name of the manager machine.

•  All the sub-directories used for rendering must be shared. This includes all texture maps and output directories.

	TIP Use the UNC (Universal Naming Convention) directory convention for all paths. Using just the drive letter for things like texture map and output directories may cause the server to look at the wrong drive. Instead of C:\3DStudio Max 3\maps\refmap.gif, name the path \\COMPUTER_NAME\C:\3DStudio Max 3\maps\refmap.gif.

Setting Up Network Rendering for MAX

Once you have your network set up to meet the above conditions, you can set up network rendering in MAX.

1.  Make sure MAX is authorized on the machine you intend to be the manager (probably your main workstation). Launch Manager.exe.

2.  Make sure MAX is authorized on all the server machines and launch Server.exe on each one.

3.  Click the Properties button at the bottom of the server window. In the Manager Name or IP address, enter the name of the Manager machine. Leave all other settings alone. Close, then restart Server. It should register to the Manager right away.

	NOTE MAX will automatically find the manager on the network if the Automatic box is checked. You may also manually enter a machine name to prevent accidental rendering through another manager.

Sending a Network Render

Let’s look at how to send off a network render.

1.  From one of the network render stations, launch the scene you want to network render.

2.  Make sure all of your map paths (in Customize Ø Configure Paths), as well as all the map names used in scene materials in the Material Editor, are named with UNC names. (Unfortunately you must do this manually.)

3.  Making sure the camera view is active, click the Render button.

4.  Set your render settings in the Common Parameters and Scanline rollouts. Uncheck Virtual Frame Buffer and check Net Render.

5.  Make sure the desired camera view is being rendered, the output file path is named, and Save File is checked. It doesn’t hurt to be extra careful about this, if you’d like to avoid creating your own agonizing war story about a long, wasted render.

	WARNING You must use a UNC name for your output path as well. Remember that you can only render to single frames if you want to distribute the work between more than one server machine.

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