psychopy.tools.gltools.createMeshGrid

psychopy.tools.gltools.createMeshGrid(size=(1.0, 1.0), subdiv=0, tessMode='diag')[source]

Create a grid mesh.

Procedurally generate a grid mesh by specifying its size and number of sub-divisions. Texture coordinates are computed automatically. The origin is at the center of the mesh. The generated grid is perpendicular to the +Z axis, origin of the grid is at its center.

Parameters
  • size (tuple or float) – Dimensions of the mesh. If a single value is specified, the plane will be square. Provide a tuple of floats to specify the width and length of the plane (eg. size=(0.2, 1.3)).

  • subdiv (int, optional) – Number of subdivisions. Zero subdivisions are applied by default, and the resulting mesh will only have vertices at the corners.

  • tessMode (str, optional) – Tessellation mode. Specifies how faces are subdivided. Options are ‘center’, ‘radial’, and ‘diag’. Default is ‘diag’. Modes ‘radial’ and ‘center’ work best with an odd number of subdivisions.

Returns

Vertex attribute arrays (position, texture coordinates, and normals) and triangle indices.

Return type

tuple

Examples

Create a grid mesh and draw it:

vertices, textureCoords, normals, faces = gltools.createPlane()

vertexVBO = gltools.createVBO(vertices)
texCoordVBO = gltools.createVBO(textureCoords)
normalsVBO = gltools.createVBO(normals)
indexBuffer = gltools.createVBO(
    faces.flatten(),
    target=GL.GL_ELEMENT_ARRAY_BUFFER,
    dataType=GL.GL_UNSIGNED_INT)

vao = gltools.createVAO({0: vertexVBO, 8: texCoordVBO, 2: normalsVBO},
    indexBuffer=indexBuffer)

# in the rendering loop
gltools.drawVAO(vao, GL.GL_TRIANGLES)

Randomly displace vertices off the plane of the grid by setting the Z value per vertex:

vertices, textureCoords, normals, faces =             gltools.createMeshGrid(subdiv=11)

numVerts = vertices.shape[0]
vertices[:, 2] = np.random.uniform(-0.02, 0.02, (numVerts,)))  # Z

# you must recompute surface normals to get correct shading!
normals = gltools.calculateVertexNormals(vertices, faces)

# create a VAO as shown in the previous example here to draw it ...

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