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N64 Materials and Attributes

This chapter outlines briefly the parameters and attributes you'll use to define materials for the N64 render domain.

The N64 Domain

Materials and Inheritance

 Materials are groups of attributes which determine the appearance of an object in a rendered scene. In N·World, materials are separate data structures, which you must associate with objects using the Nichimen Browser. This system provides for enhanced flexibility, since you can define a single material and apply it to many objects. In object based systems, you must redefine object attributes for each object in a scene.

Materials can be assigned to an entire object or to a selected face part of an object (a face part is a collection of faces from the object). Materials you want to use with the Nintendo 64 must be defined in the N64 render domain. This domain has several properties and unique parameters, which you control with the Attributes Editor menus.

The method for creating materials is no different for the N64 domain than for any other domain. To learn how to create materials, as well as how to specify attribute inheritance from one material to another, see the Attributes Editor & N-Render User's Guide.

The Attributes Editor

You define materials using the Attributes Editor. To launch the Attributes Editor, (CLICK-L) on the Attributes button in the config bar.

Figure 2.1 The Attributes Editor menu for the N64 render domain.

N64 Domain Defaults

(Click-L) on the Prefs button to define a number of settings for the N64 domain.

Figure 2.2 N64 domain defaults

Map Directory

The default directory from which maps are read.

Image Output Directory

At certain times, N64 Express will need to convert image files into a format suitable for inclusion in N64 data. This operation doesn't affect your original image files, but does result in a new file being written. Use the Image Output Directory preference to specify a location for N64 to use to write these files.

The default value is the /tmp/ directory. Files in this directory are, of course, deleted every time you reboot your machine. Using the /tmp/ machine is convenient if all you want to do is preview your textures. However, specifying a more permanent location prevents N64 Express from having to convert texture maps more than once. Also, you can save the converted maps and use them later when it comes time to port your content to the N64.

Preshade Object?

If set to Yes, the lights in the Default Light Group are used to preshade the object before it is sent to the Nintendo 64. See the Attributes Editor User's Guide for more information on setting up light groups.

Update Camera?

If set to Yes, the position of the camera on the Nintendo 64 is updated to follow the position of the camera in the N-Geometry window.

Note. You may experience gimbal lock on the display of the Nintendo 64 if you rotate the camera and look at the object straight down along the Y axis. This is an unavoidable effect often encountered in 3D simulations.

Max World Coords

Scaling factor used when converting the floating point coordinate values (used to represent objects in N-World) to a fixed point coordinate value on the Nintendo 64. A higher value means your objects will appear smaller on the Nintendo 64, while a lower value means your objects will appear larger.

The LISP formula used to convert the floating point value to a fixed point value is as follows:

(round (* 32768 (/ number *max-coord-value*)))
This takes the floating point value passed, divides it by the max-coord-value, then multiplies it by 32768, and finally rounds it to an integer. (The max-coord-value variable is the Max World Coords value specified.)

So, for example, if we passed a floating point value of 1.0, and had specified a Max World Coords of 1000, we'd get the following calculation:

(round (* 32768 (/ 1.0 1000)))
which would return:

32

Save Preferences/Done

 (CLICK-L) on Done to update defaults with any changes you have made. If you want to make your changes to the N64 domain defaults permanent, (Click-L) on the Save Preferences button at the bottom of the window.

N64 Attributes

N64 Attributes are divided into two sections:, Shader and Texture. Shader parameters control how the shader renders the scene, while Texture parameters control how texture maps are applied to objects in a scene.

Shader Attributes

Color

 Default: White

The color attribute is used for two purposes in the N64 render domain:

If you apply a map over an object or part that has a color other than white, the appearance of that map is altered. For example, if you apply a red brick texture onto a yellow cube, the bricks would take on a yellowish hue (how yellow depends on the RGB value of the yellow assigned to the cube).

Facing Control

Default: Front

Omit Face?

Default: No

Smooth Shade?

Default: No

The smooth shade parameter selects either "color by vertex" or "color by face." (Figure 2.3)

Figure 2.3 Color by vertex vs. color by face

Preshade

Default: Yes

Texture Parameters

Texture Map

 Default: None

Specify the pathname for the texture map to be applied to the face, part, or body. The application of texture maps through mappers is described in more detail in the Attributes Editor User's Guide.

The size and number of texture maps which can be sent to the Nintendo 64 are limited only by the texture map memory available.

N64 Domain Commands

Revert

Redisplay

Reset

(CLICK-L) on Reset to reset the attached Nintendo 64.

Preview

(CLICK-L) on Preview to send all the objects in the current scene to the Nintendo 64.

Faces Larger than 4K

If your object contains faces that use more than 4K of texture map memory, an error message appears, telling you that such faces exist on your object. The object is not sent over, and the faces are collected in N-Geometry for you.

With the faces still selected, (Shift-L) on the collection and use the Cut command to cut the individual faces to a smaller size (select pairs of vertices to cut the face). See the N-Geometry Reference Guide for more information about using the cut commands.


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