Creating a 3D Model and Shader System in Python

One of the easiest ways to give your video game a graphical uplift is by adding in some cool shaders. Shaders essentially change the appearance of a 3D model when it's drawn on the screen, and can make it a solid color, look like glass, or even glow! This only scratches the surface of the possibilities, too.

Using the Bridge pattern allows a 3D model to use any shader available, creating an exponential explosion of combinations and possibilities.

We won't be going over actual shader work in this demo, since it would be a little outside the scope of the lesson, but we can take a look at how such a system would be structured to allow maximum flexibility.

Shader Examples:

# In other examples we'd create base classes for the shader and model.
# Since we don't need them in Python, we'll go straight into it!

# Shader 1: Unlit color shader:
class UnlitColorShader(object):
   def __init__(self, color):
       self.color = color
   def render(self, model):
       print("Rendering {} with a {} color".format(model.getName(), self.color))

# Shader 2: Glass shader:
class GlassShader(object):
   def render(self, model):
       print("Rendering {} to look like glass.".format(model.getName()))

Model Examples:

# Model 1: A Cube:
class CubeModel(object):
   def __init__(self, shader):
       self.shader = shader
   
   def draw(self):
       self.shader.render(self)
   
   def getName(self):
       return "Cube"

# Model 2: A Monkey:
class Suzanne(object):
   def __init__(self, shader):
       self.shader = shader
   
   def draw(self):
       self.shader.render(self)
   
   def getName(self):
       return "Suzanne"

Demo:

# Create shaders:
solidRed = UnlitColorShader("red")
solidBlue = UnlitColorShader("blue")
glass = GlassShader()

# Create the models:
cube = CubeModel(solidRed)
monkey = Suzanne(glass)

# Draw the two models:
cube.draw() # "Rendering Cube with a red color."
monkey.draw() # "Rendering Suzanne to look like glass."

# Switch out the shader on suzanne:
monkey.shader = solidBlue

monkey.draw()  # "Rendering Suzanne with a blue color."