Sharedwww / talks / 2006-05-09-sage-digipen / tutorial / basic-3.pyOpen in CoCalc
Author: William A. Stein
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# Soya 3D tutorial
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# Copyright (C) 2004 Jean-Baptiste LAMY
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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# basic-3: Time management : a randomly moving sphere
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# In this lesson, we'll create a spherish head that moves around randomly.
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# You'll learn about time management (second part), vectors and coordinate-system
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# conversion.
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# Import the Soya module.
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import sys, os, os.path, random, soya
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soya.init()
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soya.path.append(os.path.join(os.path.dirname(sys.argv[0]), "data"))
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# Creates a scene.
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scene = soya.World()
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# Creates the randomly moving sphere's class. We call it head, because we'll use
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# a head-like shape.
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# This class inherits from soya.Volume, so it can have a shape (the head).
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class Head(soya.Volume):
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# Redefine the constructor.
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def __init__(self, parent):
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# Calls the soya.Volume constructor (remember, calling the super implementation is
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# always a good idea), and use the shape called 'caterpillar_head'.
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soya.Volume.__init__(self, parent, soya.Shape.get("caterpillar_head"))
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# Adds a speed attribute to our new object.
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# The speed is a Vector object. A Vector is a mathematical object, used for
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# computation ; contrary to other object (Light, Camera, Volume, World,...) it does not
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# modify the rendering in any way.
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# A vector is defined by a coordinate system and 3 coordinates (X, Y, Z) ; here the
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# speed is defined in 'self', i.e. the Head, and with coordinates 0.0, 0.0, -0.2.
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# Remember that in Soya, the -Z direction is the front. So the speed
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# This means that the speed vector is parallel to the direction the head is looking
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# at, and has a length of 0.2.
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self.speed = soya.Vector(self, 0.0, 0.0, -0.2)
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# Like advance_time, begin_round is called by the idler.
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# But contrary to advance_time, begin_round is called regularly, at the beginning of each
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# round ; thus it receive no 'proportion' argument.
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# Decision process should occurs in begin_round.
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def begin_round(self):
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# Calls the super implementation.
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soya.Volume.begin_round(self)
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# Changes the direction of the head, by rotating it around the Y axis, of a random
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# angle between -25.0 and 25.0 degrees.
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# Notice that after the rotation, the speed vector is still parallel to the direction
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# the head is looking at, since the vector is defined 'inside' the head.
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self.rotate_lateral((random.random() - 0.5) * 50.0)
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# In advance_time, we make the head advance.
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def advance_time(self, proportion):
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soya.Volume.advance_time(self, proportion)
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# Moves the head according to the speed vector.
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# add_mul_vector is identical to: self.add_vector(proportion * self.speed), but faster.
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# Notice that the head is defined is the head.parent coordinate system (e.g. the scene)
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# though the speed vector is defined in the head coordinate system.
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self.add_mul_vector(proportion, self.speed)
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# Creates a Head in the scene.
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head = Head(scene)
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# Creates a light.
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light = soya.Light(scene)
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light.set_xyz(2.0, 5.0, 0.0)
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# Creates a camera.
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camera = soya.Camera(scene)
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soya.set_root_widget(camera)
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camera.set_xyz(0.0, 15.0, 15.0)
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# Makes the camera looking at the head's initial position.
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# The look_at method is another rotation method ; it makes any 3D object looking toward
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# the given position (a 3D object or a Point), or in the given direction (if the argument
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# is a Vector).
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camera.look_at(head)
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soya.Idler(scene).idle()
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