Example GLSL shader in Panda with simple texture mapping

example.py

from panda3d.core import Shader

vshader = """#version 140

// Vertex inputs
in vec4 p3d_Vertex;
in vec2 p3d_MultiTexCoord0;

// Uniform inputs
uniform mat4 p3d_ModelViewProjectionMatrix;

// Output to fragment shader
out vec2 texcoord;

void main() {
  gl_Position = p3d_ModelViewProjectionMatrix * p3d_Vertex;
  texcoord = p3d_MultiTexCoord0;
}

"""

fshader = """#version 140

uniform sampler2D p3d_Texture0;

// Input from vertex shader
in vec2 texcoord;

void main() {
  vec4 color = texture(p3d_Texture0, texcoord);
  gl_FragColor = color.bgra;
}

"""

from direct.showbase.ShowBase import ShowBase
base = ShowBase()

model = loader.loadModel('environment')
model.reparentTo(base.render)

shader = Shader.make(Shader.SL_GLSL, vshader, fshader)
model.setShader(shader)

base.run()