psychopy.tools.mathtools.reverseProject

psychopy.tools.mathtools.reverseProject(winPos, modelView, proj, viewport=None, out=None, dtype=None)[source]

Unproject window coordinates into object or scene coordinates.

This function works like gluUnProject and can be used to find to an object or scene coordinate at the point on-screen (mouse coordinate or pixel). The coordinate can then be used to create a direction vector from the viewer’s eye location. Another use of this function is to convert depth buffer samples to object or scene coordinates. This is the inverse operation of forwardProject().

Parameters:
  • winPos (array_like) – Window coordinates (x, y, z). If viewport is not specified, these should be normalized device coordinates. If an Nx3 array of coordinates is specified, where each row contains a window coordinate this function will return an array of unprojected coordinates with the same size. Usually, you only need to specify the x and y coordinate, leaving z as zero. However, you can specify z if sampling from a depth map or buffer to convert a depth sample to an actual location.

  • modelView (array_like) – 4x4 combined model and view matrix for returned value to be object coordinates. Specify only the view matrix for a coordinate in the scene.

  • proj (array_like) – 4x4 projection matrix used for rendering.

  • viewport (array_like) – Viewport rectangle for the window [x, y, w, h]. Do not specify one if winPos is in already in normalized device coordinates.

  • out (ndarray, optional) – Optional output array. Must be same shape and dtype as the expected output if out was not specified.

  • dtype (dtype or str, optional) – Data type for computations can either be ‘float32’ or ‘float64’. If out is specified, the data type of out is used and this argument is ignored. If out is not provided, ‘float64’ is used by default.

Returns:

Object or scene coordinates.

Return type:

ndarray


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