diff --git a/game/game.py b/game/game.py
index ad30abe..7abc63f 100644
--- a/game/game.py
+++ b/game/game.py
@@ -13,24 +13,26 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import time
 from math import pi, tau, dist
-from ctypes import Structure
 
 from engine import *
 
 from game import math
-from game import triangles
-from game import sea
-from game.shader import Shader
-from game.generator import Generator
-from game.resources import RuntimeArchive
-from game.batch import Batch
-from game.camera import Camera
-from game.environment import Environment
+from game.time import Time
 from game.events import Events
 from game.mouse import Mouse
 from game.keyboard import Keyboard
+from game.generator import Generator
+from game.resources import RuntimeArchive
+from game.texture import Texture
+from game.shader import Shader
+from game.camera import Camera
+from game.environment import Environment
+from game.inputs import InputFloat
+from game.batch import Batch
+from game.scene import SceneNode, TextureNode, ShaderNode, InputNode, DrawNode, FuncNode
+from game.triangles import SkyTriangles
+from game import sea
 
 proj_hfov = pi * 0.25
 proj_ratio = 16.0 / 9.0
@@ -40,27 +42,49 @@ proj_far_z = 3000.0
 sun_direction = math.vec3_normalize((1.0, 0.0, 0.5))
 sun_power = 1.0
 
-def main():
-    print("Generating terrain...")
-    gen_begin = time.thread_time()
-    generated = Generator(256)
-    gen_end = time.thread_time()
-    print("Done: ", round(gen_end - gen_begin, 2), "seconds")
+def update_camera(time, mouse, camera, environment):
+    camera_yaw = mouse.drag[0] * 0.001
+    camera_pitch = mouse.drag[1] * 0.001 + pi * 0.25
+    camera_distance = mouse.wheel * 20.0
+    camera.set_view(camera_yaw, camera_pitch, camera_distance)
+    environment.from_sun(camera.view, sun_direction, sun_power)
 
+def update_tests(time, blob_translation, blob_spawn_translation, cube_translation, cube_spawn_translation, cube_orientation, clouds_orientation):
+    rotation = mat3()
+    mat3_rotation(rotation, vec3_up, (time.current * 0.21) % tau)
+    mat3_mul_vec3(blob_translation, rotation, blob_spawn_translation)
+    mat3_mul_vec3(cube_translation, rotation, cube_spawn_translation)
+    mat3_rotation(cube_orientation, vec3_up, (time.current * 0.43) % tau)
+    mat3_rotation(clouds_orientation, vec3_up, (time.current * -0.037) % tau)
+
+def update_sea(time, camera, sea_phase):
+    camera.to_km()
+    sea_phase.update((time.current * 0.023) % 1.0)
+
+def main():
     print("Initializing...")
     display = create_display(b'RK Island - Drag to rotate, wheel to zoom, q to quit', 1600, 900)
     events = Events(display)
     mouse = Mouse(events, wheel = 60, wheel_min = 20)
     keyboard = Keyboard(events)
     render_initialize(__debug__)
-    terrain_shader = Shader('terrain', 'common')
+
+    tiles_shader = Shader('terrain', 'common')
     tests_shader = Shader('tests', 'common')
     sky_shader = Shader('sky')
 
-    heightmap = create_texture(
+    camera = Camera()
+    camera.set_projection(proj_hfov, proj_ratio, proj_near_z, proj_far_z)
+    environment = Environment()
+    sea_phase = InputFloat(sky_shader.u_sea_phase, 0.0)
+
+    print("Generating terrain...")
+    generated = Generator(256)
+
+    heightmap = Texture(
         TEXTURE_FORMAT_FLOAT_32, 256, 256, 0, TEXTURE_FLAG_MIN_LINEAR | TEXTURE_FLAG_MAG_LINEAR,
         generated.packed_heights)
-    normalmap = create_texture(
+    normalmap = Texture(
         TEXTURE_FORMAT_RGB10_A2, 256, 256, 0, TEXTURE_FLAG_MIN_LINEAR | TEXTURE_FLAG_MAG_LINEAR,
         generated.packed_normals)
 
@@ -77,7 +101,7 @@ def main():
     rock_model = archive.get_model('rock')
     mud_model = archive.get_model('mud')
     lava_model = archive.get_model('lava')
-    terrain_batch = Batch(tiles_vertices, generated.size ** 2, 8, translation = PARAM_FORMAT_VEC3_SHORT)
+    tiles_batch = Batch(tiles_vertices, generated.size ** 2, 8, translation = PARAM_FORMAT_VEC3_SHORT)
 
     #TODO: generator & for real
     vc = generated.volcano_c
@@ -108,7 +132,7 @@ def main():
             model = mud_model
         else:
             model = rock_model
-        model.spawn(terrain_batch, vec3(float(((mx - 128) * 8) + 4), float(((127 - my) * 8) + 4), 0.0))
+        model.spawn(tiles_batch, vec3(float(((mx - 128) * 8) + 4), float(((127 - my) * 8) + 4), 0.0))
 
     tests_texture = archive.get_texture('tests')
     tests_vertices = archive.get_vertices('tests')
@@ -118,153 +142,75 @@ def main():
     tests_batch = Batch(tests_vertices, 3, 3,
         translation = PARAM_FORMAT_VEC3_FLOAT,
         orientation = PARAM_FORMAT_MAT3_INT10 | PARAM_FORMAT_NORMALIZE)
+
     blob_spawn_translation = vec3(-100.0, -500.0, 0.0)
-    cube_spawn_translation = vec3(100.0, -500.0, 0.0)
     blob_forward = math.vec3_normalize((sun_direction[0], sun_direction[1], 0.0))
     blob_right = math.vec3_cross(blob_forward, math.vec3_up)
-    blob_id = blob_model.spawn(tests_batch,
-        blob_spawn_translation, mat3(vec3(*blob_right), vec3(*blob_forward), vec3_up))
+    blob_spawn_orientation = mat3(vec3(*blob_right), vec3(*blob_forward), vec3_up)
+    blob_id = blob_model.spawn(tests_batch, blob_spawn_translation, blob_spawn_orientation)
+    blob_translation = tests_batch.translation[blob_id]
+    cube_spawn_translation = vec3(100.0, -500.0, 0.0)
     cube_id = cube_model.spawn(tests_batch, cube_spawn_translation, mat3_identity)
+    cube_translation = tests_batch.translation[cube_id]
+    cube_orientation = tests_batch.orientation[cube_id]
     clouds_id = clouds_model.spawn(tests_batch, vec3(0.0, 0.0, 32.0), mat3_identity)
+    clouds_orientation = tests_batch.orientation[clouds_id]
 
     sea_polar_textures = sea.load_polar_textures(('data/sea_bump1.png', 'data/sea_bump2.png'))
     sea_detail_texture = sea.load_detail_texture('data/sea_bump.png')
-    sky_triangles = create_triangles(triangles.sky_triangles(64, proj_far_z - 0.1, proj_ratio))
+    sky_triangles = SkyTriangles(64, proj_far_z - 0.1, proj_ratio)
 
-    camera = Camera()
-    camera.set_projection(proj_hfov, proj_ratio, proj_near_z, proj_far_z)
-    environment = Environment()
-
-    blob_translation = tests_batch.translation[blob_id]
-    cube_translation = tests_batch.translation[cube_id]
-    cube_orientation = tests_batch.orientation[cube_id]
-    clouds_orientation = tests_batch.orientation[clouds_id]
+    scene = SceneNode(
+        FuncNode(update_camera, (mouse, camera, environment)),
+        TextureNode((tiles_texture, heightmap, normalmap),
+            ShaderNode(tiles_shader,
+                InputNode(tiles_shader, camera),
+                InputNode(tiles_shader, environment),
+                DrawNode(tiles_batch)
+            )
+        ),
+        FuncNode(update_tests, (blob_translation, blob_spawn_translation, cube_translation, cube_spawn_translation, cube_orientation, clouds_orientation)),
+        TextureNode((tests_texture, heightmap, normalmap),
+            ShaderNode(tests_shader,
+                InputNode(tests_shader, camera),
+                InputNode(tests_shader, environment),
+                DrawNode(tests_batch)
+            )
+        ),
+        FuncNode(update_sea, (camera, sea_phase)),
+        TextureNode((sea_polar_textures, sea_detail_texture),
+            ShaderNode(sky_shader,
+                InputNode(sky_shader, camera),
+                InputNode(sky_shader, environment),
+                InputNode(sky_shader, sea_phase),
+                DrawNode(sky_triangles)
+            )
+        )
+    )
 
     print("Running... Ctrl+c to quit")
-    start_time = time.monotonic()
-    current_time = 0.0
-    frame = 0
-    frame_min = 10000.0
-    frame_max = 0.0
-    frame_avg = 0.0
-    draw_min = 10000.0
-    draw_max = 0.0
-    draw_avg = 0.0
-    perf_count = 0
+    time = Time()
     try:
-        while True:
-            current_time = time.monotonic() - start_time
-            frame_begin = time.thread_time()
-
+        while not keyboard.quit:
             events.update()
-            if keyboard.quit:
-                break
-
             begin_frame()
-
-            camera_distance = mouse.wheel * 20.0
-            camera_yaw = mouse.drag[0] * 0.001
-            camera_pitch = mouse.drag[1] * 0.001 + pi * 0.25
-            camera.set_view(camera_yaw, camera_pitch, camera_distance)
-            environment.from_sun(camera.view, sun_direction, sun_power)
-
-            terrain_shader.select()
-            camera.set_inputs(terrain_shader)
-            environment.set_inputs(terrain_shader)
-            select_texture(0, tiles_texture)
-            select_texture(1, heightmap)
-            select_texture(2, normalmap)
-            draw_begin = time.thread_time()
-            terrain_batch.draw()
-            draw_end = time.thread_time()
-            unselect_texture(0, tiles_texture)
-            unselect_texture(1, heightmap)
-            unselect_texture(2, normalmap)
-            terrain_shader.unselect()
-
-            rotation = mat3()
-            mat3_rotation(rotation, vec3_up, (current_time * 0.21) % tau)
-            mat3_mul_vec3(blob_translation, rotation, blob_spawn_translation)
-            mat3_mul_vec3(cube_translation, rotation, cube_spawn_translation)
-            mat3_rotation(cube_orientation, vec3_up, (current_time * 0.43) % tau)
-            mat3_rotation(clouds_orientation, vec3_up, (current_time * -0.037) % tau)
-
-            tests_shader.select()
-            camera.set_inputs(tests_shader)
-            environment.set_inputs(tests_shader)
-            select_texture(0, tests_texture)
-            select_texture(1, heightmap)
-            select_texture(2, normalmap)
-            tests_batch.draw()
-            unselect_texture(0, tests_texture)
-            unselect_texture(1, heightmap)
-            unselect_texture(2, normalmap)
-            tests_shader.unselect()
-
-            camera.to_km()
-
-            sky_shader.select()
-            camera.set_inputs(sky_shader)
-            environment.set_inputs(sky_shader)
-            set_input_float(sky_shader.u_sea_phase, (current_time * 0.023) % 1.0)
-            select_texture(0, sea_polar_textures)
-            select_texture(1, sea_detail_texture)
-            draw_triangles(sky_triangles)
-            unselect_texture(0, sea_polar_textures)
-            unselect_texture(1, sea_detail_texture)
-            sky_shader.unselect()
-
-            frame_end = time.thread_time()
+            time.update()
+            scene.draw(time)
             end_frame()
             swap_buffers(display)
-
-            if frame > 0:
-                draw_ms = draw_end - draw_begin
-                draw_min = min(draw_min, draw_ms)
-                draw_max = max(draw_max, draw_ms)
-                draw_avg += draw_ms
-                frame_ms = frame_end - frame_begin
-                frame_min = min(frame_min, frame_ms)
-                frame_max = max(frame_max, frame_ms)
-                frame_avg += frame_ms
-                perf_count += 1
-            frame += 1
-
     except KeyboardInterrupt:
         pass
 
-    print("\rDraw  *", perf_count,
-        ": min =", round(draw_min * 1000.0, 2),
-        ", max =", round(draw_max * 1000.0, 2),
-        ", avg =", round((draw_avg / perf_count) * 1000.0, 2), "ms")
-
-    print("\rFrame *", perf_count,
-        ": min =", round(frame_min * 1000.0, 2),
-        ", max =", round(frame_max * 1000.0, 2),
-        ", avg =", round((frame_avg / perf_count) * 1000.0, 2), "ms")
-
-    # seed 666
-    #    for _ in range(10000):
-    #        current_time = 0 # time.monotonic() - start_time
-
-    # Draw  * 9999 : min = 0.14 , max = 0.43 , avg = 0.19 ms
-    # Draw  * 9999 : min = 0.14 , max = 0.35 , avg = 0.19 ms
-    # Draw  * 9999 : min = 0.13 , max = 0.44 , avg = 0.18 ms
-
-    # Frame * 9999 : min = 0.21 , max = 0.7 , avg = 0.33 ms
-    # Frame * 9999 : min = 0.2 , max = 0.54 , avg = 0.31 ms
-    # Frame * 9999 : min = 0.19 , max = 0.6 , avg = 0.29 ms
-
     print("Quitting...")
     del tests_batch
-    del terrain_batch
-    destroy_texture(sea_polar_textures)
-    destroy_texture(sea_detail_texture)
-    destroy_texture(heightmap)
-    destroy_texture(normalmap)
-    destroy_triangles(sky_triangles)
+    del tiles_batch
+    del sky_triangles
+    del sea_polar_textures
+    del sea_detail_texture
+    del heightmap
+    del normalmap
     archive.destroy()
-    del terrain_shader
+    del tiles_shader
     del tests_shader
     del sky_shader
     render_terminate()
diff --git a/game/inputs.py b/game/inputs.py
new file mode 100644
index 0000000..b4616d3
--- /dev/null
+++ b/game/inputs.py
@@ -0,0 +1,29 @@
+# Copyright (C) 2022 RozK
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from engine import set_input_float
+
+class InputFloat:
+    __slots__ = '_input', 'value'
+
+    def __init__(self, input, value):
+        self._input = input
+        self.value = value
+
+    def update(self, value):
+        self.value = value
+
+    def set_inputs(self, shader):
+        set_input_float(self._input, self.value)
diff --git a/game/resources.py b/game/resources.py
index 2982503..98848f6 100644
--- a/game/resources.py
+++ b/game/resources.py
@@ -20,6 +20,7 @@ from pathlib import Path
 import png
 
 import engine
+from game.texture import Texture
 
 VERTEX_SIZE = 20
 VERTEX_FORMAT = engine.vertex_format(
@@ -133,7 +134,7 @@ class TextureData:
         _write_blob(file, self.pixels)
 
 def create_texture(data):
-    return engine.create_texture(data.format, data.width, data.height, data.nlevels, data.flags, data.pixels)
+    return Texture(data.format, data.width, data.height, data.nlevels, data.flags, data.pixels)
 
 class VerticesData:
     __slots__ = 'name', 'vertices', 'indices'
@@ -208,8 +209,6 @@ class Archive:
     def destroy(self):
         for vertices in self.vertices_db.values():
             engine.destroy_vertices(vertices)
-        for texture in self.textures_db.values():
-            engine.destroy_texture(texture)
         self.textures_db.clear()
         self.vertices_db.clear()
         self.models_db.clear()
diff --git a/game/scene.py b/game/scene.py
new file mode 100644
index 0000000..a52354c
--- /dev/null
+++ b/game/scene.py
@@ -0,0 +1,95 @@
+# Copyright (C) 2022 RozK
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+class Node:
+    __slots__ = '_subnodes'
+
+    def __init__(self, *subnodes):
+        self._subnodes = subnodes
+
+    def draw(self, time):
+        for subnode in self._subnodes:
+            subnode.draw(time)
+
+class SceneNode(Node):
+    __slots__ = '_subnodes'
+
+    def __init__(self, *subnodes):
+        Node.__init__(self, *subnodes)
+        self._subnodes = subnodes
+
+    def draw(self, time):
+        Node.draw(self, time)
+
+class TextureNode(Node):
+    __slots__ = '_textures'
+
+    def __init__(self, textures, *subnodes):
+        Node.__init__(self, *subnodes)
+        self._textures = textures
+
+    def draw(self, time):
+        for slot, texture in enumerate(self._textures):
+            texture.select(slot)
+        Node.draw(self, time)
+        for slot, texture in enumerate(self._textures):
+            texture.unselect(slot)
+
+class ShaderNode(Node):
+    __slots__ = '_shader'
+
+    def __init__(self, shader, *subnodes):
+        Node.__init__(self, *subnodes)
+        self._shader = shader
+
+    def draw(self, time):
+        self._shader.select()
+        Node.draw(self, time)
+        self._shader.unselect()
+
+class InputNode(Node):
+    __slots__ = '_shader', '_input'
+
+    def __init__(self, shader, input, *subnodes):
+        Node.__init__(self, *subnodes)
+        self._shader = shader
+        self._input = input
+
+    def draw(self, time):
+        self._input.set_inputs(self._shader)
+        Node.draw(self, time)
+
+class DrawNode(Node):
+    __slots__ = '_drawable'
+
+    def __init__(self, drawable, *subnodes):
+        Node.__init__(self, *subnodes)
+        self._drawable = drawable
+
+    def draw(self, time):
+        self._drawable.draw()
+        Node.draw(self, time)
+
+class FuncNode(Node):
+    __slots__ = '_func', '_params'
+
+    def __init__(self, func, params, *subnodes):
+        Node.__init__(self, *subnodes)
+        self._func = func
+        self._params = params
+
+    def draw(self, time):
+        self._func(time, *self._params)
+        Node.draw(self, time)
diff --git a/game/sea.py b/game/sea.py
index 8815b4b..bfed466 100644
--- a/game/sea.py
+++ b/game/sea.py
@@ -17,10 +17,10 @@ from itertools import product
 from math import tau, cos, sin, copysign
 from array import array
 
-from engine import (create_texture,
-    TEXTURE_FORMAT_RGB10_A2, TEXTURE_FORMAT_TYPECODE, TEXTURE_FLAG_MIN_LINEAR, TEXTURE_FLAG_MAG_LINEAR)
+from engine import TEXTURE_FORMAT_RGB10_A2, TEXTURE_FORMAT_TYPECODE, TEXTURE_FLAG_MIN_LINEAR, TEXTURE_FLAG_MAG_LINEAR
 
 from game.math import vec3_scale, vec3_direction, vec3_cross, vec3_normal_rgb10a2
+from game.texture import Texture
 from game.resources import load_png
 
 _format = TEXTURE_FORMAT_RGB10_A2
@@ -51,7 +51,7 @@ def load_polar_textures(paths, waves_height = 0.008):
         _width, _height, normals = load_texture(path)
         assert _width == width and _height == height
         data.extend(list(map(_conv, normals)))
-    return create_texture(_format, width, height, len(paths), _flags, data)
+    return Texture(_format, width, height, len(paths), _flags, data)
 
 def load_detail_texture(path, scale = 0.5, waves_height = 0.002):
     width, height, data = load_png(path)
@@ -68,4 +68,4 @@ def load_detail_texture(path, scale = 0.5, waves_height = 0.002):
         return vec3_scale(n, copysign(1.0, n[2]))
     normals = list(map(normal, product(range(height), range(width)), data))
     data = array(_typecode, list(map(_conv, normals)))
-    return create_texture(_format, width, height, 0, _flags, data)
+    return Texture(_format, width, height, 0, _flags, data)
diff --git a/game/texture.py b/game/texture.py
new file mode 100644
index 0000000..19a507c
--- /dev/null
+++ b/game/texture.py
@@ -0,0 +1,31 @@
+# Copyright (C) 2022 RozK
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from engine import create_texture, select_texture, unselect_texture, destroy_texture
+
+class Texture:
+    __slots__ = '_texture'
+
+    def __init__(self, format, width, height, nlevels, flags, pixels):
+        self._texture = create_texture(format, width, height, nlevels, flags, pixels)
+
+    def __del__(self):
+        destroy_texture(self._texture)
+
+    def select(self, slot):
+        select_texture(slot, self._texture)
+
+    def unselect(self, slot):
+        unselect_texture(slot, self._texture)
diff --git a/game/time.py b/game/time.py
new file mode 100644
index 0000000..e2bc2bb
--- /dev/null
+++ b/game/time.py
@@ -0,0 +1,29 @@
+# Copyright (C) 2022 RozK
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from time import monotonic
+
+class Time:
+    __slots__ = '_start', 'current', 'delta'
+
+    def __init__(self):
+        self._start = monotonic()
+        self.current = 0.0
+        self.delta = 0.0
+
+    def update(self):
+        current = monotonic() - self._start
+        self.delta = current - self.current
+        self.current = current
diff --git a/game/triangles.py b/game/triangles.py
index 82c3c96..a5838db 100644
--- a/game/triangles.py
+++ b/game/triangles.py
@@ -16,35 +16,49 @@
 from itertools import chain
 from array import array
 from math import cos, sin
+from engine import create_triangles, draw_triangles, destroy_triangles
 
-# TODO: with FOV
-def sky_triangles(vsubdivs, distance, projection_ratio):
-    assert vsubdivs > 0
-    vertices = []
-    hsubdivs = round(vsubdivs * projection_ratio)
-    z = -distance
-    width = distance * projection_ratio
-    height = distance
-    startx = width * -0.5
-    starty = height * -0.5
-    stepx = width / hsubdivs
-    stepy = height / vsubdivs
-    y1 = starty
-    y2 = y1 + stepy
-    for sy in range(vsubdivs):
-        x1 = startx
-        x2 = x1 + stepx
-        for sx in range(hsubdivs):
-            a = (x1, y2, z)
-            b = (x2, y1, z)
-            vertices.append((x1, y1, z))
-            vertices.append(b)
-            vertices.append(a)
-            vertices.append((x2, y2, z))
-            vertices.append(a)
-            vertices.append(b)
-            x1 = x2
-            x2 += stepx
-        y1 = y2
-        y2 += stepy
-    return array('f', chain.from_iterable(vertices))
+class Triangles:
+    __slots__ = '_triangles'
+
+    def __init__(self, triangles):
+        self._triangles = create_triangles(triangles)
+
+    def __del__(self):
+        destroy_triangles(self._triangles)
+
+    def draw(self):
+        draw_triangles(self._triangles)
+
+class SkyTriangles(Triangles):
+    # TODO: with FOV
+    def __init__(self, vsubdivs, distance, projection_ratio):
+        assert vsubdivs > 0
+        vertices = []
+        hsubdivs = round(vsubdivs * projection_ratio)
+        z = -distance
+        width = distance * projection_ratio
+        height = distance
+        startx = width * -0.5
+        starty = height * -0.5
+        stepx = width / hsubdivs
+        stepy = height / vsubdivs
+        y1 = starty
+        y2 = y1 + stepy
+        for sy in range(vsubdivs):
+            x1 = startx
+            x2 = x1 + stepx
+            for sx in range(hsubdivs):
+                a = (x1, y2, z)
+                b = (x2, y1, z)
+                vertices.append((x1, y1, z))
+                vertices.append(b)
+                vertices.append(a)
+                vertices.append((x2, y2, z))
+                vertices.append(a)
+                vertices.append(b)
+                x1 = x2
+                x2 += stepx
+            y1 = y2
+            y2 += stepy
+        super().__init__(array('f', chain.from_iterable(vertices)))