def drawObjModel(viewToClipTfm, worldToViewTfm, modelToWorldTfm, model):
# Lighting/Shading is very often done in view space, which is why a transformation that lands positions in this space is needed
modelToViewTransform = worldToViewTfm * modelToWorldTfm
# this is a special transform that ensures that normal vectors remain orthogonal to the
# surface they are supposed to be even in the prescence of non-uniform scaling.
# It is a 3x3 matrix as vectors don't need translation anyway and this transform is only for vectors,
# not points. If there is no non-uniform scaling this is just the same as Mat3(modelToViewTransform)
modelToViewNormalTransform = lu.inverse(
lu.transpose(lu.Mat3(modelToViewTransform)))
# Bind the shader program such that we can set the uniforms (model.render sets it again)
glUseProgram(model.defaultShader)
# transform (rotate) light direction into view space (as this is what the ObjModel shader wants)
viewSpaceLightDirection = [0.0, 0.0, -1.0]
glUniform3fv(
glGetUniformLocation(model.defaultShader, "viewSpaceLightDirection"),
1, viewSpaceLightDirection)
# This dictionary contains a few transforms that are needed to render the ObjModel using the default shader.
# it would be possible to just set the modelToWorld transform, as this is the only thing that changes between
# the objects, and compute the other matrices in the vertex shader.
# However, this would push a lot of redundant computation to the vertex shader and makes the code less self contained,
# in this way we set all the required parameters explicitly.
transforms = {
"modelToClipTransform":
viewToClipTfm * worldToViewTfm * modelToWorldTfm,
"modelToViewTransform": modelToViewTransform,
"modelToViewNormalTransform": modelToViewNormalTransform,
}
model.render(None, None, transforms)
def setCommonUniforms(self, shader, view, modelToWorldTransform):
# Concatenate the transformations to take vertices directly from model space to clip space
modelToClipTransform = view.viewToClipTransform * view.worldToViewTransform * modelToWorldTransform
# Transform to view space from model space (used for the shading)
modelToViewTransform = view.worldToViewTransform * modelToWorldTransform
# Transform to view space for normals, need to use the inverse transpose unless only rigid body & uniform scale.
modelToViewNormalTransform = lu.inverse(
lu.transpose(lu.Mat3(modelToViewTransform)))
# Set the standard transforms, these vary per object and must be set each time an object is drawn (since they have different modelToWorld transforms)
lu.setUniform(shader, "modelToClipTransform", modelToClipTransform)
lu.setUniform(shader, "modelToViewTransform", modelToViewTransform)
lu.setUniform(shader, "modelToViewNormalTransform",
modelToViewNormalTransform)
# These transforms are the same for the current view and could be set once for all the objects
lu.setUniform(shader, "worldToViewTransform",
view.worldToViewTransform)
lu.setUniform(shader, "viewToClipTransform", view.viewToClipTransform)
# Lighting parameters as could these
viewSpaceLightPosition = lu.transformPoint(view.worldToViewTransform,
g_sunPosition)
lu.setUniform(shader, "viewSpaceLightPosition", viewSpaceLightPosition)
lu.setUniform(shader, "globalAmbientLight", g_globalAmbientLight)
lu.setUniform(shader, "sunLightColour", g_sunLightColour)
lu.bindTexture(g_TU_shadow, g_shadowTexId)
lu.setUniform(shader, "shadowMapTexture", g_shadowTexId)
def render_frame(width, height):
""" Renders the frame """
global g_shader
global g_squares
global g_square_colors
global g_square_normals
global g_cam
global g_light_1
global g_light_color_1
global g_ambi_color
global g_spec_color
# Make the camera position
eye_pos = g_cam
look_at = [1.5, 1.5, -1.5]
up_dir = [0, 1, 0]
y_fov = 45
# Light constants
ambient_light = g_ambi_color
specular_light = g_spec_color
world_to_view = lu.make_lookAt(eye_pos, look_at, up_dir)
view_to_clip = lu.make_perspective(y_fov, width / height, 0.1, 260)
world_to_clip = view_to_clip * world_to_view
model_to_view_normal = lu.inverse(lu.transpose(lu.Mat3(world_to_view)))
# Make openGL use transform from screen space to NDC
glViewport(0, 0, width, height)
# Set the clear colour (i.e. background colour)
glClearColor(0.7, 0.8, 1.0, 1.0)
make_squares()
make_texture_coords()
# Unbind the buffers
glBindBuffer(GL_ARRAY_BUFFER, 0)
glBindVertexArray(0)
# Clear the colour and depth buffers
glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT)
# Buffer the world to clip transform matrix
tfm_uniform_index = glGetUniformLocation(g_shader, "worldToClipTfm")
glUseProgram(g_shader)
glUniformMatrix4fv(tfm_uniform_index, 1, GL_TRUE, world_to_clip.getData())
glBindVertexArray(g_vertex_array)
model_uniform_index = glGetUniformLocation(g_shader, "modelToView")
glUseProgram(g_shader)
glUniformMatrix4fv(model_uniform_index, 1, GL_TRUE, world_to_view.getData())
norm_uniform_index = glGetUniformLocation(g_shader, "modelToViewNormal")
glUseProgram(g_shader)
glUniformMatrix3fv(norm_uniform_index, 1, GL_TRUE,
model_to_view_normal.getData())
lu.setUniform(g_shader, "camPos", eye_pos)
# Add light 1 uniforms
lu.setUniform(g_shader, "lightColourAndIntensity1", g_light_color_1)
lu.setUniform(g_shader, "viewSpaceLightPosition1", g_light_1)
# Add light 2 uniforms
lu.setUniform(g_shader, "lightColourAndIntensity2", g_light_color_2)
lu.setUniform(g_shader, "viewSpaceLightPosition2", g_light_2)
# Add light 3 uniforms
lu.setUniform(g_shader, "lightColourAndIntensity3", g_light_color_3)
lu.setUniform(g_shader, "viewSpaceLightPosition3", g_light_3)
# Add light 4 uniforms
lu.setUniform(g_shader, "lightColourAndIntensity4", g_light_color_4)
lu.setUniform(g_shader, "viewSpaceLightPosition4", g_light_4)
lu.setUniform(g_shader, "ambientLightColourAndIntensity", ambient_light)
lu.setUniform(g_shader, "materialSpecular", specular_light)
# Fog settings
lu.setUniform(g_shader, "fogColor", g_fog_color)
lu.setUniform(g_shader, "fogDensityConst", g_fog_density)
lu.setUniform(g_shader, "fogHeightConst", g_fog_height)
lu.setUniform(g_shader, "fogMax", g_fog_max)
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_2D, g_texture_id)
loc = glGetUniformLocation(g_shader, "plasticTexture")
glUniform1i(loc, 0)
for i in range(int(len(g_squares) / 4)):
lu.setUniform(g_shader, "squareColorIndex", g_square_colors[i])
lu.setUniform(g_shader, "squareNormal", g_square_normals[i])
glDrawArrays(GL_TRIANGLE_FAN, i * 4, 4)
