PyGLy¶

Co-ordinate Systems¶

Transforms¶

Manipulation of 3D spaces is performed through the use of Transform classes. These provide access to common functions related to translation and orientation of objects in 3D space.

PyGLy provides two types of Transform classes: Transform, and WorldTransform. These objects differ in the co-ordinate systems the functions manipulate.

The Transform class implements Local Space manipulations. Modifications done using the Transform class are performed with no understanding of World Space. When used outside of a hierarchy, the Transform space is relative to World Space. When used inside a hierarchy, the Transform space is relative to the parent’s Local Space.

The WorldTransform class implements World Space manipulations. A WorldTransform object is linked to a Transform object. Modifications done using the WorldTransform class are performed in World Space. This can be used to set absolute positioning of an object despite it’s parent’s transform.

The WorldTransform class implements the TreeNode class which adds the concept of a hierarchy. WorldTransforms can be joined together in a Parent - Child tree (1 parent maximum). This enables the inheritance of parent transforms.

Usage of WorldTransform or Transform objects is not mutually exclusive. Modifications performed on the WorldTransform or the linked Transform object are propagated to each other.

Transform Spaces¶

Each Transform class exposes two co-ordinate spaces, Object Space, and Inertial Space.

When using Object Space, the X,Y and Z axis inherit the orientation from the Object. As the Object’s orientation changes, the X,Y and Z axis presented by functions change accordingly.

When using Inertial Space, the X,Y and Z axis remain fixed regardless of the Object’s orientation.

Object Space¶

The Object Space co-ordinate system’s axis are fixed to the object’s orientation. As the object is rotated, the Object Space axis will change with the object.

Object Transform Space.

See also

Object Space

Inertial Space¶

The Inertial Space co-ordinate system orientation is relative to it’s parent orientation. When there is no parent, the co-ordinate system is the same as the global World Space. The Inertial Space axis does not change when the object is rotated.

Inertial Transform Space

See also

Inertial Space

Common Functions¶

Common Utilities¶

Legacy¶

Viewport¶

Ratio Viewport¶

View Matrix¶

Perspective View Matrix¶

Orthogonal View Matrix¶

Object Space¶

Inertial Space¶

Transform¶

World Transform¶

Tree Node¶

Tree Leaf¶

class pygly.tree_leaf.TreeLeaf[source]¶

Base class for Tree Leaf objects.

Supports a single parent. Cannot have children.

__init__()[source]¶

Creates a tree leaf object.

parent¶

The current parent of the node or None if there isn’t one.

This is an @property decorated method which allows retrieval and assignment of the scale value.

predecessors()[source]¶

Returns successive parents of the node.

Generator function that allows iteration up the tree.

Scene Node¶

Camera Node¶

Render Node¶

Render Callback Node¶

OpenGL¶

Shaders¶

Buffers¶

class pygly.vertex_array.VertexArray[source]¶

Wraps OpenGL Vertex Array Objects.

Provides wrappers around standard functions and higher level wrappers with PyGLy.BufferRegion interfaces.

Example:

vs = Shader( GL_VERTEX_SHADER, shader_source['vert'] )
fs = Shader( GL_FRAGMENT_SHADER, shader_source['frag'] )
shader = ShaderProgram( vs, fs )

# a basic triangle
vertices = numpy.array(
    [
        #  X    Y    Z          R    G    B
        (( 0.0, 1.0, 0.0),     (1.0, 0.0, 0.0)),
        ((-2.0,-1.0, 0.0),     (0.0, 1.0, 0.0)),
        (( 2.0,-1.0, 0.0),     (0.0, 0.0, 1.0)),
        ],
    dtype = [
        ('position','float32',(3,)),
        ('colour','float32',(3,))
        ]
    )
buffer = DtypeVertexBuffer(
    vertices.dtype,
    GL_ARRAY_BUFFER,
    GL_STATIC_DRAW,
    data = vertices
    )

vao = VertexArray()

vao.bind()
buffer.bind()
buffer.set_attribute_pointer_dtype( shader, 'in_position', 'position' )
buffer.set_attribute_pointer_dtype( shader, 'in_colour', 'colour' )
buffer.unbind()
vao.unbind()

Warning

This is an OpenGL Core function (>=3.0) and should not be called for Legacy profile applications (<=2.1).

__init__()[source]¶

bind()[source]¶

handle¶

unbind()[source]¶

Texturing¶

Sorting¶