Scalar Definitions

Definition & Usage

<Scalar> scalar-name { value }

Scalars can appear in various contexts. They are always optional, and specify some attribute value relevant to the current context.

The scalar name is the name of the attribute; different attribute names are meaningful in different contexts.

The value is either a numeric or a (quoted or unquoted) string value; the interpretation as a number or as a string depends on the nature of the named attribute.

Alpha Scalars

Image Alpha File

<Scalar> alpha-file { alpha-filename }

If this scalar is present, the texture file’s alpha channel is read in from the named image file (which should contain a grayscale image), and the two images are combined into a single two- or four-channel image internally. This is useful for loading alpha channels along with image file formats like JPEG that don’t

Image Alpha File Channel

<Scalar> alpha-file-channel { channel }

This defines the channel that should be extracted from the file named by alpha-file to determine the alpha channel for the resulting channel.

The default is 0, which means the grayscale combination of r, g, b. Otherwise, this should be the 1-based channel number, for instance 1, 2, or 3 for r, g, or b, respectively, or 4 for the alpha channel of a four-component image.

Alpha Blending

<Scalar> alpha { alpha-type }

This specifies whether and what type of transparency will be performed. Alpha-type may be one of:

OFF
ON
BLEND
BLEND_NO_OCCLUDE
MS
MS_MASK
BINARY
DUAL

If alpha-type is OFF, it means not to enable transparency, even if the image contains an alpha channel or the format is RGBA. If alpha-type is ON, it means to enable the default transparency, even if the image filename does not contain an alpha channel. If alpha-type is any of the other options, it specifies the type of transparency to be enabled.

Blend Mode (Group)

<Scalar> blend { mode }

Specifies that a special blend mode should be applied geometry at this level and below. The available options are none, add, subtract, inv-subtract, min, and max. See ColorBlendAttrib.

<Scalar> blendop-a { mode }
<Scalar> blendop-b { mode }

If blend mode, above, is not none, this specifies the A and B operands to the blend equation. Common options are zero, one, incoming-color, one-minus-incoming-color. See ColorBlendAttrib for the complete list of available options. The default is “one”.

<Scalar> blendr { red-value }
<Scalar> blendg { green-value }
<Scalar> blendb { blue-value }
<Scalar> blenda { alpha-value }

If blend mode, above, is not none, and one of the blend operands is constant-color or a related option, this defines the constant color that will be used.

Image Scalars

Image Compression

<Scalar> compression { compression-mode }

Defines an explicit control over the real-time compression mode applied to the texture. The various options are:

DEFAULT
OFF
ON
FXT1
DXT1
DXT2
DXT3
DXT4
DXT5

This controls the compression of the texture when it is loaded into graphics memory, and has nothing to do with on-disk compression such as JPEG.

If this option is omitted or DEFAULT, then the texture compression is controlled by the compressed-textures config variable.

If it is OFF, texture compression is explicitly off for this texture regardless of the setting of the config variable; if it is “ON”, texture compression is explicitly on, and a default compression algorithm supported by the driver is selected.

If any of the other options, it names the specific compression algorithm to be used.

Image Format

<Scalar> format { format-definition }

This defines the load format of the image file.

The format-definition is one of:

RGBA
RGBM
RGBA12
RGBA8
RGBA4
RGB
RGB12
RGB8
RGB5
RGB332
LUMINANCE_ALPHA
RED
GREEN
BLUE
ALPHA
LUMINANCE

The formats whose names end in digits specifically request a particular texel width. RGB12 and RGBA12 specify 48-bit texels with or without alpha; RGB8 and RGBA8 specify 32-bit texels, and RGB5 and RGBA4 specify 16-bit texels. RGB332 specifies 8-bit texels.

The remaining formats are generic and specify only the semantic meaning of the channels. The size of the texels is determined by the width of the components in the image file. RGBA is the most general; RGB is the same, but without any alpha channel.

RGBM is like RGBA, except that it requests only one bit of alpha, if the graphics card can provide that, to leave more room for the RGB components, which is especially important for older 16-bit graphics cards (the “M” stands for “mask”, as in a cutout).

The number of components of the image file should match the format specified; if it does not, the egg loader will attempt to provide the closest match that does.

Environment Type

<Scalar> envtype { environment-type }

This specifies the type of texture environment to create; i.e. it controls the way in which textures apply to models. Environment-type may be one of:

MODULATE
DECAL
BLEND
REPLACE
ADD
BLEND_COLOR_SCALE
MODULATE_GLOW
MODULATE_GLOSS
*NORMAL
*NORMAL_HEIGHT
*GLOW
*GLOSS
*HEIGHT
*SELECTOR

The default environment type is MODULATE, which means the texture color is multiplied with the base polygon (or vertex) color. This is the most common texture environment by far. Other environment types are more esoteric and are especially useful in the presence of multitexture. In particular, the types prefixed by an asterisk (*) require enabling Panda’s automatic ShaderGenerator.

Image Combine Modes

<Scalar> combine-rgb { combine-mode }
<Scalar> combine-alpha { combine-mode }
<Scalar> combine-rgb-source0 { combine-source }
<Scalar> combine-rgb-operand0 { combine-operand }
<Scalar> combine-rgb-source1 { combine-source }
<Scalar> combine-rgb-operand1 { combine-operand }
<Scalar> combine-rgb-source2 { combine-source }
<Scalar> combine-rgb-operand2 { combine-operand }
<Scalar> combine-alpha-source0 { combine-source }
<Scalar> combine-alpha-operand0 { combine-operand }
<Scalar> combine-alpha-source1 { combine-source }
<Scalar> combine-alpha-operand1 { combine-operand }
<Scalar> combine-alpha-source2 { combine-source }
<Scalar> combine-alpha-operand2 { combine-operand }

These options replace the envtype and specify the texture combiner mode, which is usually used for multitexturing. This specifies how the texture combines with the base color and/or the other textures applied previously. You must specify both an rgb and an alpha combine mode. Some combine-modes use one source/operand pair, and some use all three; most use just two.

combine-mode may be one of:

REPLACE
MODULATE
ADD
ADD-SIGNED
INTERPOLATE
SUBTRACT
DOT3-RGB
DOT3-RGBA

combine-source may be one of:

TEXTURE
CONSTANT
PRIMARY-COLOR
PREVIOUS
CONSTANT_COLOR_SCALE
LAST_SAVED_RESULT

combine-operand may be one of:

SRC-COLOR
ONE-MINUS-SRC-COLOR
SRC-ALPHA
ONE-MINUS-SRC-ALPHA

The default values if any of these are omitted are:

<Scalar> combine-rgb { modulate }
<Scalar> combine-alpha { modulate }
<Scalar> combine-rgb-source0 { previous }
<Scalar> combine-rgb-operand0 { src-color }
<Scalar> combine-rgb-source1 { texture }
<Scalar> combine-rgb-operand1 { src-color }
<Scalar> combine-rgb-source2 { constant }
<Scalar> combine-rgb-operand2 { src-alpha }
<Scalar> combine-alpha-source0 { previous }
<Scalar> combine-alpha-operand0 { src-alpha }
<Scalar> combine-alpha-source1 { texture }
<Scalar> combine-alpha-operand1 { src-alpha }
<Scalar> combine-alpha-source2 { constant }
<Scalar> combine-alpha-operand2 { src-alpha }

Image Min/Mag Filtering

<Scalar> minfilter { filter-type }
<Scalar> magfilter { filter-type }
<Scalar> magfilteralpha { filter-type }
<Scalar> magfiltercolor { filter-type }

This specifies the type of filter applied when minimizing or maximizing.

Filter-type may be one of:

NEAREST
LINEAR
NEAREST_MIPMAP_NEAREST
LINEAR_MIPMAP_NEAREST
NEAREST_MIPMAP_LINEAR
LINEAR_MIPMAP_LINEAR

There are also some additional filter types that are supported for historical reasons, but each of those additional types maps to one of the above. New egg files should use only the above filter types.

Image Mipmaps

<Scalar> read-mipmaps { flag }

If this flag is nonzero, then pre-generated mipmap levels will be loaded along with the texture. In this case, the filename should contain a sequence of one or more hash mark (#) characters, which will be filled in with the mipmap level number; the texture filename thus determines a series of images, one for each mipmap level. The base texture image is mipmap level 0.

If this flag is specified in conjunction with a 3D or cube map texture (as specified above), then the filename should contain two hash mark sequences, separated by a character such as an underscore, hyphen, or dot. The first sequence will be filled in with the mipmap level index, and the second sequence will be filled in with the 3D sequence or cube map face.

Image Anisotropic Degree

<Scalar> anisotropic-degree { degree }

Enables anisotropic filtering for the texture, and specifies the degree of filtering. If the degree is 0 or 1, anisotropic filtering is disabled. The default is disabled.

Image Border Color

<Scalar> borderr { red-value }
<Scalar> borderg { green-value }
<Scalar> borderb { blue-value }
<Scalar> bordera { alpha-value }

These define the “border color” of the texture, which is particularly important when one of the UV wrap modes is BORDER_COLOR.

Image Type

<Scalar> type { texture-type }

This may be one of the following attributes:

1D
2D
3D
CUBE_MAP

The default is 2D, which specifies a normal, 2-d texture. If any of the other types is specified instead, a texture image of the corresponding type is loaded.

If 3D or CUBE_MAP is specified, then a series of texture images must be loaded to make up the complete texture; in this case, the texture filename is expected to include a sequence of one or more hash mark (#) characters, which will be filled in with the sequence number. The first image in the sequence must be numbered 0, and there must be no gaps in the sequence. In this case, a separate alpha-file designation is ignored; the alpha channel, if present, must be included in the same image with the color channel(s).

Multiview Textures

<Scalar> multiview { flag }

If this flag is nonzero, the texture is loaded as a multiview texture. In this case, the filename must contain a hash mark (#) as in the 3D or CUBE_MAP case, above, and the different images are loaded into the different views of the multiview textures. If the texture is already a cube map texture, the same hash sequence is used for both purposes: the first six images define the first view, the next six images define the second view, and so on. If the texture is a 3-D texture, you must also specify num-views, below, to tell the loader how many images are loaded for views, and how many are loaded for levels.

A multiview texture is most often used to load stereo textures, where a different image is presented to each eye viewing the texture, but other uses are possible, such as for texture animation.

<Scalar> num-views { count }

This is used only when loading a 3-D multiview texture. It specifies how many different views the texture holds; the z height of the texture is then implicitly determined as (number of images) / (number of views).

Texture Generation Mode

<Scalar> tex-gen { mode }

This specifies that texture coordinates for the primitives that reference this texture should be dynamically computed at runtime, for instance to apply a reflection map or some other effect. The valid values for mode are:

EYE_SPHERE_MAP (or SPHERE_MAP)
WORLD_CUBE_MAP
EYE_CUBE_MAP (or CUBE_MAP)
WORLD_NORMAL
EYE_NORMAL
WORLD_POSITION
EYE_POSITION
POINT_SPRITE

Texture Priority

<Scalar> priority { priority-value }

Specifies an integer sort value to rank this texture in priority among other textures that are applied to the same geometry. This is only used to eliminate low-priority textures in case more textures are requested for a particular piece of geometry than the graphics hardware can render.

Texture Quality level

<Scalar> quality-level { quality }

Sets a hint to the renderer about the desired performance / quality tradeoff for this particular texture. This is most useful for the tinydisplay software renderer; for normal, hardware-accelerated renderers, this may have little or no effect.

This may be one of:

DEFAULT
FASTEST
NORMAL
BEST

“Default” means to use whatever quality level is specified by the global texture-quality-level config variable.

Texture Stage Scalars

Stage Name

<Scalar> stage-name { name }

Specifies the name of the TextureStage object that is created to render this texture. If this is omitted, a custom TextureStage is created for this texture if it is required (e.g. because some other multitexturing parameter has been specified), or the system default TextureStage is used if multitexturing is not required.

Saved Result

<Scalar> saved-result { flag }

If flag is nonzero, then it indicates that this particular texture stage will be supplied as the “last_saved_result” source for any future texture stages.

Material Scalars

Material Components

<Scalar> diffr { number }
<Scalar> diffg { number }
<Scalar> diffb { number }
<Scalar> diffa { number }

<Scalar> ambr { number }
<Scalar> ambg { number }
<Scalar> ambb { number }
<Scalar> amba { number }

<Scalar> emitr { number }
<Scalar> emitg { number }
<Scalar> emitb { number }
<Scalar> emita { number }

<Scalar> specr { number }
<Scalar> specg { number }
<Scalar> specb { number }
<Scalar> speca { number }

The four color groups, diff*, amb*, emit*, and spec* specify the diffuse, ambient, emission, and specular components of the lighting equation, respectively. Any of them may be omitted; the omitted component(s) take their color from the native color of the primitive, otherwise the primitive color is replaced with the material color.

These properties collectively define a “material” that controls the lighting effects that are applied to a surface; a material is only in effect in the presence of lighting.

Material Shininess

<Scalar> shininess { number }
<Scalar> local { flag }

The shininess property controls the size of the specular highlight, and the value ranges from 0 to 128.

A larger value creates a smaller highlight (creating the appearance of a shinier surface).

Render Order Scalars

Bin Order

<Scalar> bin { bin-name }

For textures, this specifies the bin name order of all polygons with this texture applied, in the absence of a bin name specified on the polygon itself.

For polygons, this specifies the bin name for all polygons at or below this node that do not explicitly set their own bin.

Draw Order

<Scalar> draw-order { number }

This specifies the fixed drawing order of all polygons with this texture applied, in the absence of a drawing order specified on the polygon itself.

For Groups: This specifies the drawing order for all polygons at or below this node that do not explicitly set their own drawing order. See the description of draw-order for geometry attributes, above.

Visibility

<Scalar> visibility { hidden | normal }

If the visibility of a group is set to hidden, the primitives nested within that group are not generated as a normally visible primitive.

If the Config.prc variable egg-suppress-hidden is set to true, the primitives are not converted at all; otherwise, they are converted as a “stashed” node.

Render Node Types

Portal

<Scalar> portal { boolean-value }

Used on a rectangular polygon to set it as a PortalNode. This portal is used by the camera to “see through” to the other cells. Meaning, when the camera is looking through the portal, the cell on the other side of the portal window is made visible.

Note: Nodes tagged a PortalNode will not be inherently visible in the scene graph, but will still report a bounding volume.

Polylight

<Scalar> polylight { boolean-value }

Create a polylight instead of a regular polyset.

Note: Nodes tagged with polylight will be flagged as a PolylightNode in the scene graph with a Radius attribute. These nodes are not inherently visible in the scene graph and will not report a bounding volume.

Occluder

<Scalar> occluder { boolean-value }

This makes the first (or only) polygon within this group node into an OccluderNode. The polygon must have exactly four vertices. An occluder polygon is invisible. When the occluder is activated with model.set_occluder(occluder), objects that are behind the occluder will not be drawn. This can be a useful rendering optimization for complex scenes, but should not be overused or performance can suffer.

See “Polygon Occluder Culling” for more usage information.

Depth Buffer Scalars

For textures: Specifies special depth buffer properties of all polygons with this texture applied.

Depth Offset

<Scalar> depth-offset { number }

Depth Write

<Scalar> depth-write { mode }

Depth Test

<Scalar> depth-test { mode }

For Groups: Specifies special depth buffer properties of all polygons at or below this node that do not override this.

Decal Properties

<Scalar> decal { boolean-value }

If this is present and boolean-value is non-zero, it indicates that the geometry below this level is coplanar with the geometry at this level, and the geometry below is to be drawn as a decal onto the geometry at this level. This means the geometry below this level will be rendered “on top of” this geometry, but without the Z-fighting artifacts one might expect without the use of the decal flag.

<Scalar> decalbase { boolean-value }

This can optionally be used with the decal scalar, above. If present, it should be applied to a sibling of one or more nodes with the decal scalar on. It indicates which of the sibling nodes should be treated as the base of the decal. In the absence of this scalar, the parent of all decal nodes is used as the decal base. This scalar is useful when the modeling package is unable to parent geometry nodes to other geometry nodes.

UV Scalars

UV Name

<Scalar> uv-name { name }

Specifies the name of the texture coordinates that are to be associated with this texture.

If this is omitted, the default texture coordinates are used.

UV Scroll Mode

<Scalar> scroll_u { speed }
<Scalar> scroll_v { speed }
<Scalar> scroll_w { speed }
<Scalar> scroll_r { speed }

This declares a scroll speed on the texture image.

speed can be a floating point value.

UV Wrap Mode

<Scalar> wrap { repeat-definition }
<Scalar> wrapu { repeat-definition }
<Scalar> wrapv { repeat-definition }
<Scalar> wrapw { repeat-definition }

This defines the behavior of the texture image outside of the normal (u,v) range 0.0 - 1.0.

It is REPEAT to repeat the texture to infinity, CLAMP not to.

The wrapping behavior may be specified independently for each axis via wrapu and wrapv, or it may be specified for both simultaneously via wrap.

Although less often used, for 3-d textures wrapw may also be specified, and it behaves similarly to wrapu and wrapv.

There are other legal values in additional to REPEAT and CLAMP. The full list is:

CLAMP
REPEAT
MIRROR
MIRROR_ONCE
BORDER_COLOR

Animation Scalars

FPS

<Scalar> fps { frame-rate }

This specifies the rate of animation for a SequenceNode (created when the Switch flag is specified). A value of zero indicates a SwitchNode should be created instead.

NURBS Scalars

NURBS Type

<Scalar> type { curve-type }

This defines the semantic meaning of this curve, either XYZ, HPR, or T. If the type is XYZ, the curve will automatically be transformed between Y-up and Z-up if necessary; otherwise, it will be left alone.

NURBS Subdivision

<Scalar> subdiv { num-segments }

If this scalar is given and nonzero, Panda will create a visible representation of the curve when the scene is loaded. The number represents the number of line segments to draw to approximate the curve.

<Scalar> U-subdiv { u-num-segments }
<Scalar> V-subdiv { v-num-segments }

These define the number of subdivisions to make in the U and V directions to represent the surface. A uniform subdivision is always made, and trim curves are not respected (though they will be drawn in if the trim curves themselves also have a subdiv parameter). This is only intended as a cheesy visualization.

PointLight Scalars

Thickness

<Scalar> thick { number }

This specifies the size of the PointLight (or the width of a line), in pixels, when it is rendered. This may be a floating-point number, but the fractional part is meaningful only when anti-aliasing is in effect. The default is 1.0.

Perspective

<Scalar> perspective { boolean-value }

If this is specified, then the thickness, above, is to interpreted as a size in 3-d spatial units, rather than a size in pixels, and the point should be scaled according to its distance from the viewer normally.

Collide Scalars

<Scalar> collide-mask { value }
<Scalar> from-collide-mask { value }
<Scalar> into-collide-mask { value }

Sets the CollideMasks on the collision nodes and geometry nodes created at or below this group to the indicated values. These are bits that indicate which objects can collide with which other objects. Setting collide-mask is equivalent to setting both from-collide-mask and into-collide-mask to the same value.

The value may be an ordinary decimal integer, or a hex number in the form 0x000, or a binary number in the form 0b000.