[ < ] | [ > ] | [ << ] | [ Up ] | [ >> ] | [Top] | [Contents] | [Index] | [ ? ] |
type
can be either a float
or a color
), at the specified texture coordinates. If no texture coordinates are provided, s and t will be used. An optional channel can be specified to select a starting channel in the texture, this can be useful when a texture contains more that three channels. Use tdlmake
to prepare your textures for improved performance and memory usage (see section 3.3 Using the Texture Optimizer - tdlmake
). texture()
accepts a list of optional parameters as summerized in the table below.
EXAMPLE
/* Sharper result (width<1) */ color c = texture( "grid.tdl", s, t, "width", 0.8 ); /* Returns the green component */ float green = texture( "grid.tdl"[1] ); /* Returns the alpha channel, or 1.0 (opaque) if no alpha channel is present */ float alpha = texture( "grid.tdl"[3], "fill", 1.0 ); |
texture()
, an optional channel can be specified to select a starting channel when performing texture lookups. Use tdlmake
to prepare cubic and long-lat envmaps. If an unprepared TIFF is given to environment()
, it will be considered as a lat-long environment map. environement()
recognizes the same list of optional parameters as texture()
.
EXAMPLE
/* Do an env lookup */ normal Nf = faceforward( N, I ); color c = environment( "env.tdl", Nf ); /* Only fetch the alpha channel, if no alpha present, returns 1 */ float red_comp = environment( "env.tdl"[3], Nf, "fill", 1 ); |
Name | Type | Default | Description |
"blur" | varying float
| 0 | Specifies an additional area to be added to the texture lookup area in both s and t, expressed in units of texture coordinates (range = [0..1]). A value of 1.0 would request that the entire texture be blurred in the result; |
"sblur" | varying float
| 0 | Specifies "blur" in s only; |
"tblur" | varying float
| 0 | Specifies "blur" in t only; |
"width" | uniform float
| 1 | Multiplies the width of the filtered area in both s and t; |
"swidth" | uniform float
| 1 | Specifies "width" in s only; |
"twidth" | uniform float
| 1 | Specifies "width" in t only; |
"samples" | uniform float
| 4 | Specifies the sampling rate. Only useful for environment() , texture() uses an addaptative sampling algorithm;
|
"fill" | uniform float
| 0 | If a channel is not present in the texture, use this value; |
"filter" | uniform string
| "gaussian"
| Specifies the reconstruction filter to use when accessing the texture map. Supported filters are: `gaussian', `triangle' and `box'. |
texture()
and environment()
optional parameters.
"!"
or "shadow"
. Note that if ray tracing is used, only objects tagged as visible to shadows will be considered (using Attribute "visibility" "transmission"
, section 4.2 Attributes). Optional parameters to shadow()
are described in the table below. For additional information about shadow maps and deep shadow maps refer to section 5.1 Shadows.
Name | Type | Default | Description |
"blur" | varying float
| 0 | Specifies an additional area to be added to the texture lookup area in both s and t, expressed in units of texture coordinates (range = [0..1]). A value of 1.0 would request that the entire texture be blurred in the result; |
"sblur" | varying float
| 0 | Specifies "blur" in s only; |
"tblur" | varying float
| 0 | Specifies "blur" in t only; |
"width" | uniform float
| 1.0 | Multiplies the width of the filtered area in both s and t; |
"swidth" | uniform float
| 1.0 | Specifies "width" in s only; |
"twidth" | uniform float
| 1.0 | Specifies "width" in t only; |
"samples" | uniform float
| 16 | Specifies the number of samples to use for shadow lookups. This influances the antialis quality. A value of 16 is recommended for shadow maps and, 4 for deep shadow maps; |
"bias" | varying float
| 0.225 | Used to prevent self-shadowing. If set to 0, the global bias will be used, as specified by Option "shadow" "bias" (see section 4.1 Options);
|
shadow()
optional parameters.
[ < ] | [ > ] | [ << ] | [ Up ] | [ >> ] | [Top] | [Contents] | [Index] | [ ? ] |