matrix¶

(module)

A module for setting the current matrices used with various graphics functions in Codea

General¶

matrix.push()¶: Push the current matrix onto the stack, saving the current transform

matrix.pop()¶: Pop the matrix from the stack, restoring the previous transform

matrix.reset()¶: Reset the current matrix to the identity matrix

matrix.model()¶: Gets the model matrix used to transform from local to world space

matrix.model(matrix): Sets the model matrix used to transform from local to world space

matrix.view()¶: Gets the view matrix used to transform from world to view space

matrix.view(matrix): Sets the view matrix used to transform from world to view space (generally controlled by cameras)

matrix.projection()¶: Gets the projection matrix used for final projection

matrix.projection(matrix): Sets the projection matrix, used for final projection (i.e. ortho and perspective projection)

Transform¶

matrix.transform2d(x, y[, sx = 1, sy = 1, r = 0])¶: Apply a generic 2D transform to the model matrix

matrix.transform3d(x, y, z, sx, sy, sz, rx, ry, rz)¶: Apply a generic 3D transform to the model matrix

matrix.translate(x, y[, z])¶: Translate the current model matrix

matrix.rotate(quat)¶

matrix.rotate(angle, x, y, z): Rotate the current model matrix

matrix.scale(x, y[, z])¶: Scale the current model matrix

Projection¶

Note

Codea 4.x uses a left-handed, +Z-forward coordinate system for 3D rendering. When matrix.perspective() is active, the camera is at the origin looking toward +Z. Objects must be translated to positive Z to appear in front of the camera. This is the opposite of the -Z-forward convention used in OpenGL and Codea 3.x Craft.

-- Minimal 3D draw loop
matrix.push()
    matrix.perspective(60)          -- 60° FOV, camera at origin, +Z forward
    matrix.translate(0, 0, 4)       -- object 4 units in front
    matrix.rotate(angle, 0, 1, 0)
    myMesh:draw()
matrix.pop()

matrix.ortho()¶: Set the projection matrix to ortho using the device screen settings (i.e. coordinates range [0, 0] to [WIDTH, HEIGHT])

matrix.ortho(height)

Sets an orthographic projection matrix height units high, using the aspect ratio of the screen to set the width

Parameters:: height – The height of the orthographic projection

matrix.ortho(left, right, bottom, top[, near, far]): Sets an orthographic projection matrix using the supplied edge values

matrix.perspective(fov, aspect, near, far])¶: Sets a perspective projection matrix