jit.gl.light
Place a light source in a 3D scene
Description
Contains the properties needed to define a light source in OpenGL. These include light type (directional, point and spot), light color, attenuation, and spot angle and falloff. In addition a position (for point and spot) and orientation (for directional and spot) can be defined for a virtual light in 3D space.
Discussion
Multiple jit.gl.light objects can be added to a scene, up to a maximum that is specific to your graphics card.
The actual appearance of 3D objects is a combination of the material properties of that object, and the color values of the jit.gl.light objects in the scene. The possible color values are ambient, diffuse and specular. For more information, see chapter 5 of the OpenGl Redbook. This object requires one argument: the name of a drawing context. A named drawing context is a named instance of a jit.window, jit.pwindow, or jit.matrix object that has an instance of the jit.gl.render object associated with it. Additionally it can reference the name of a jit.gl.node sub-context. This value may also be set via the OB3D drawto attribute. If no argument is present, the object is implicitly added to the first valid drawing context or sub-context found in the current patch or by searching up the patcher hierarchy.
Attributes
ambient[4 floats]
The color and opacity of the ambient light component in the form red green blue opacity (default = 0. 0. 0. 1. (opaque black)) All values should be in the range 0.-1.
atten_const[float]
The constant factor in the attenuation formula: 1.0 means never attenuate, 0.0 is complete attenuation. The attenuation parameters determine how the light source diminishes with distance for point and spot type lights.
atten_linear[float]
The linear factor in the attenuation formula: 1 means attenuate evenly over the distance. The attenuation parameters determine how the light source diminishes with distance for point and spot type lights.
atten_quad[float]
The quadratic factor in the attenuation formula: adds a curvature to the attenuation formula. The attenuation parameters determine how the light source diminishes with distance for point and spot type lights.
diffuse[4 floats]
The color and opacity of the diffuse light component in the form red green blue opacity (default = 1. 1. 1. 1. (opaque white)) All values should be in the range 0.-1.
direction[3 floats]
Sets the direction the light points. Only applies to directional and spot lights.
layer[int]
The light layer controls the ordering of lights in GLSL lighting arrays (default = 0). With the gl2 engine, lights are accessed via the gl_LightSource array. Objects in the same layer have indeterminate ordering.
lookat[3 floats]
One way to set the orientation. The light will orient so that it's local Z points to the 3D position provided. (default = 0 0 0)
shadowblur[float]
7.0.0
Shadow blur amount (default = 0.2). Indicates the width of a gaussian blur performed on the shadow output texture.
shadowquality[symbol]
7.0.0
Shadow texture quality (default = med). Setting this value affects the dim and type of the internal jit.gl.texture shadow target.
Possible values:
'lo'
(
type=float16, dim=512
)
'med-lo'
(
type=float16, dim=1024
)
'med'
(
type=float32, dim=1024
)
'med-hi'
(
type=float32, dim=2048
)
'hi'
(
type=float32, dim=4096
)
shadowrange[float]
7.0.0
Shadow range value (default = 50.0). For directional lights, this represents the the maximum distance a shadow-caster can be from shadow-receiver. For spot/point lights the maximum range a light will affect other objects. Setting this as low as possible in the scene generally gives better shadow results.
shadows[int]
7.0.0
Enable shadow casting from this light (default = 0).
shadowtexoutname[symbol]
read-only7.0.0
The internal shadow texture output name.
specular[4 floats]
Color and opacity of specular light component (default = 1. 1. 1. 1. (opaque white)) The first three floats in the range 0.-1. specify the RGB components of the specular light color. The fourth float (also in the range 0.-1.) specifies opacity.
spot_angle[float]
Defines the cone angle for spot type lights (default = 90)
spot_falloff[float]
Defines the rate of falloff of the light from the center, to the edges of the cone (default = 0). Only applies to spot type lights.
type[symbol]
Light casting type (default = directional).
Possible values:
'point'
(
Models a positional source illuminating in all directions
)
Point lights ignore rotation and direction attributes. Attenuation attributes (atten_const, atten_linear, and atten_quad) affect intensity.
'directional'
(
Models an infinitely far away light with parallel rays (e.g. the sun)
)
Directional lights ignore position and attenuation attributes.
'spot'
(
Models a positional source illuminating in a specific direction
)
Cone shape is determined by spot_angle with a falloff determined by spot_falloff. Attenuation attributes (atten_const, atten_linear, and atten_quad) affect intensity.
'hemisphere'
(
(GLCore only) Also known as "sky and ground" lighting.
)
Hemisphere lights are similar to directional but the light is cast from both above (sky), and below (ground). Sky color is set from diffuse and ground from ambient color attributes. Hemisphere lights ignore position and attenuation attributes.
viewproj_matrix[symbol]
read-only7.0.0
Shadow camera current view-projection matrix
OB3D Attributes
anim[symbol]
The name of a jit.anim.node object that handles all spatial transforms for this instance (default = UID). The default value references an internal object, but can be overridden by setting to the name of an existing external jit.anim.node instance. This allows for more advanced control of the spatial transform.
anchor[3 floats]
The anchor position in local space (default = 0. 0. 0.). Allows for offsetting the local 3D origin around which transforms are applied.
animmode[symbol]
Determines which space the anim_move and anim_turn messages will affect the position and orientation of this object (default = parent).
local = Rotate relative to local axis
parent = Rotate relative to parent axis
world = Rotate relative to world axis
axes[int]
x/y/z axis rendering off/on (default = 0)
drawto[symbol]
The named drawing context in which to draw (default = none) A named drawing context is a named instance of a jit.window, jit.pwindow, or jit.matrix object that has an instance of the jit.gl.render object associated with it.
enable[int]
Enable flag (default = 1) When the flag is set, drawing is enabled.
filterclass[symbol]
The name of this object's pick filter class (default = default). This controls the visibility of objects to the jit.gl.handle and jit.gl.picker objects. In order to select this object, the filterclass value must be in the picking object's filters list.
name[symbol]
The instance name (default = UID)
position[3 floats]
The 3D origin in the form x y z (default = 0. 0. 0.)
quat[4 floats]
The current rotation as a quaternion(default = 0. 0. 0. 1.). A quaternion is a mathematical construct that is a four dimensional vector, and can be visualized as a rotation around an arbitrary axis. Quaternions are a useful representation of an orientation in 3D space.
rotate[4 floats]
The angle of rotation and the xyz vector about which the rotation is performed in the form rotation-angle x y z (default = 0. 0. 0. 1.)
rotatexyz[3 floats]
Sets the current rotation to the concatenation of rotations about the positive x, y, and z axes, also known as Euler angles (default = 0. 0. 0.). The default order is yzx and can be changed with the jit.gl.render rotate_order attribute. Angles are expressed in degrees.
scale[3 floats]
The 3D scaling factor in the form x y z (default = 1. 1. 1.)
transform_reset[int]
Modelview and projection transform reset flag (default = 0) When the flag is set, the modelview and projection transforms are set to the identity transform before rendering the object. This is useful for sprite or billboard overlays, or automatic scaling to window size. The transform_reset flag modes are:
0 = do nothing (default)
1 = proportional orthographic glOrtho(-aspect, aspect, -1.0, 1.0, near_clip, far_clip);
2 = orthographic normalized glOrtho(-1.0, 1.0, -1.0, 1.0, near_clip, far_clip);
3 = proportional perspective with near clip = 0.001 gluPerspective(lens_angle, aspect, 0.001/*near_clip*/, far_clip);
4 = normalized perspective with near clip = 0.001 gluPerspective(lens_angle, 1.0, 0.001/*near_clip*/, far_clip);
viewalign[int]
View aligned transformation flag (default = 0)
Common Box Attributes
annotation[symbol]
Sets the text that will be displayed in the Clue window when the user moves the mouse over the object.
background[int]: 0
Adds or removes the object from the patcher's background layer. background 1 adds the object to the background layer, background 0 removes it. Objects in the background layer are shown behind all objects in the default foreground layer.
color[4 floats]
Sets the color for the object box outline.
fontface[int]
Sets the type style used by the object. The options are:
plain
bold
italic
bold italic
Possible values:
0 = 'regular'
1 = 'bold'
2 = 'italic'
3 = 'bold italic'
fontname[symbol]
Sets the object's font.
fontsize[float]
Sets the object's font size (in points).
Possible values:
'8'
'9'
'10'
'11'
'12'
'13'
'14'
'16'
'18'
'20'
'24'
'30'
'36'
'48'
'64'
'72'
hint[symbol]
Sets the text that will be displayed in as a pop-up hint when the user moves the mouse over the object in a locked patcher.
ignoreclick[int]: 0
Toggles whether an object ignores mouse clicks in a locked patcher.
jspainterfile[symbol]
JS Painter File
patching_rect[4 floats]: 0. 0. 100. 0.
Sets the position and size of the object in the patcher window.
position[2 floats]
write-only
Sets the object's x and y position in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its size unchanged.
presentation[int]: 0
Sets whether an object belongs to the patcher's presentation.
presentation_rect[4 floats]: 0. 0. 0. 0.
Sets the x and y position and width and height of the object in the patcher's presentation, leaving its patching position unchanged.
rect[4 floats]
write-only
Sets the x and y position and width and height of the object in both patching and presentation modes (if the object belongs to its patcher's presentation).
size[2 floats]
write-only
Sets the object's width and height in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its position unchanged.
textcolor[4 floats]
Sets the color for the object's text in RGBA format.
textjustification[int]
Sets the justification for the object's text.
Possible values:
0 = 'left'
1 = 'center'
2 = 'right'
varname[symbol]
Sets the patcher's scripting name, which can be used to address the object by name in pattr, scripting messages to thispatcher, and the js object.
Messages
sendoutput
Send the shadow output texture a message
OB3D Messages
bang
Equivalent to the draw message.
draw
Draws the object in the named drawing destination. If the matrixoutput attribute is supported and set to 1, the geometry matrices are sent out the object's left outlet.
drawraw
Equivalent to draw with the inherit_all attribute set to 1.
drawimmediate
Equivalent to draw but ignoring any potential renderer setup
anim_move
Move the object along the axis provided, relative to the space indicated by animmode.
- x
[float]
- y
[float]
- z
[float]
anim_turn
Rotate the object along each axis by the amount provided, relative to the space indicated by animmode.
- x
[float]
- y
[float]
- z
[float]
anim_grow
Scale the object along each axis by the amount provided.
- x
[float]
- y
[float]
- z
[float]
anim_reset
Reset the local transformation attributes to their default values (position = 0 0 0, rotatexyz = 0 0 0, and scale = 1 1 1)
update_node
Update the node transformation attributes.
See Also
| Name | Description |
|---|---|
| jit.gl.render | Render Jitter OpenGL objects |
| jit.gl.sketch | Use drawing commands with OpenGL |
| jit.gl.material | Generate materials for 3D objects |