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I started working with RenderMan in 1988/89. If you're a programmer then I think the RIB interface is even easier then using GUI tools like Blender. It can be very fun to play with directly. Feed the following text into `prman`.

  Display "hacker news" "framebuffer" "rgba"
  Projection "perspective" "fov" [45]
  Translate 0 0 10
  WorldBegin
    Translate 0 -1 0
    Rotate 120 -1 0 0
    Geometry "teapot"
  WorldEnd
Then check out the Steve Upstill book "The Renderman Companion", "Advanced RenderMan" by Tony Apodaca and Larry Gritz, and the spec[1] for reference.

You can learn a lot of creative skills, geometry, animation, math, and technology from this simple interface. Note how rotations are in degrees, and commands are easily human readable. The interface was designed to be useable by people as easily as by software ("WorldBegin", cute and intuitive). Key things to remember when playing around with the RIB interface:

It's a 'right handed' coordinate system, so use your right hand to model the axis (perpendicular index finder, thumb, and middle finder form the axis). Put your thumb along the positive axis to visualize things like rotation. Above I use a negative 1 x axis (vector) to rotate 120 degrees so I can visualize the direction of rotation by pointing my right thumb to the right (negative x axis), and the direction my fingers curl is the direction of rotation.

The transformation hierarchy makes it easy to control and reason about transformations without resorting to matrix math. Use that to create easy to manipulate groups. The relevant commands are:

  # parent object
  TransformBegin
    Translate x y z
    Rotate angle x_axis y_axis z_axis
    Scale x y z
    Skew angle dx1 dy1 dz1 dx2 dy2 dz2
    # child object
    TransformBegin
      # Translate x y z...
      # ... invoke geometry
    TransformEnd
  TransformEnd

1: http://renderman.pixar.com/products/rispec/rispec_pdf/RISpec...



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