diff --git a/prettypretty/cloud.py b/prettypretty/cloud.py
new file mode 100644
index 0000000..b271d6c
--- /dev/null
+++ b/prettypretty/cloud.py
@@ -0,0 +1,154 @@
+import argparse
+import io
+from typing import Self
+
+from prettypretty.color import Color, ColorSpace
+from prettypretty.color.gamut import GamutTraversalStep
+from prettypretty.color.spectrum import (
+    CIE_ILLUMINANT_D65, CIE_OBSERVER_2DEG_1931, SpectrumTraversal
+)
+
+
+def create_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--gamut", "-g",
+        help="plot boundary of colorspace gamut; value must be sRGB, P3, or Rec2020",
+    )
+    parser.add_argument(
+        "--planar",
+        action="store_true",
+        help="plot gamut boundary in 2D",
+    )
+
+    return parser
+
+
+class PointManager:
+    def __init__(self, darken: bool = False, planar: bool = False) -> None:
+        self.darken = darken
+        self.planar = planar
+        self.points: list[tuple[float, float, float]] = []
+        self.colors: list[tuple[int, int, int]] = []
+        self.line_starts: list[int] = []
+
+    def __len__(self) -> int:
+        return len(self.points)
+
+    def add(self, color: Color) -> None:
+        x, y, z = color
+
+        if self.planar:
+            if color.space().is_ok():
+                # Zero out lightness
+                self.points.append((0, y, z))
+            else:
+                # Zero out luminosity
+                self.points.append((x, 0, z))
+        else:
+            self.points.append((x, y, z))
+
+        if self.darken:
+            lr, c, h = color.to(ColorSpace.Oklrch)
+            color = Color.oklrch(lr * 2 / 3, c * 2 / 3, h)
+
+        r, g, b = color.to_24bit()
+        self.colors.append((r, g, b))
+
+    def mark_newline(self) -> None:
+        self.line_starts.append(len(self.points))
+
+    def write_header(self, file: io.TextIOWrapper, include: None | Self = None) -> None:
+        extra = 0 if include is None else len(include)
+
+        file.write(f"element vertex {len(self.points) + extra}\n")
+        file.write("property float x\n")
+        file.write("property float y\n")
+        file.write("property float z\n")
+        file.write("property uchar red\n")
+        file.write("property uchar green\n")
+        file.write("property uchar blue\n")
+
+        # file.write(f"element face {665}\n")
+        # file.write("property list uchar int vertex_indices\n")
+
+    def write_data(self, file: io.TextIOWrapper) -> None:
+        for point, color in zip(self.points, self.colors):
+            f = 100.0
+            x, y, z = point[0] * f, point[1] * f, point[2] * f
+            r, g, b = color
+
+            file.write(f"{x:f} {y:f} {z:f} {r} {g} {b}\n")
+
+
+def render(
+    space: ColorSpace,
+    segment_size: int = 50,
+    gamut: None | ColorSpace = None,
+    planar: bool = False,
+) -> None:
+    traversal = SpectrumTraversal(CIE_ILLUMINANT_D65, CIE_OBSERVER_2DEG_1931)
+    traversal.set_step_sizes(2)
+
+    points = PointManager()
+    for step in traversal:
+        if isinstance(step, GamutTraversalStep.MoveTo):
+            points.mark_newline()
+
+        color = step.color()
+        if space.is_ok():
+            points.add(color.to(ColorSpace.Oklrab))
+        else:
+            points.add(color.to(ColorSpace.Xyz))
+
+    gamut_points = PointManager(planar=planar)
+    if gamut is not None:
+        it = gamut.gamut(segment_size)
+        assert it is not None
+        for step in it:
+            if isinstance(step, GamutTraversalStep.MoveTo):
+                gamut_points.mark_newline()
+
+            color = step.color()
+            if space.is_ok():
+                gamut_points.add(color.to(ColorSpace.Oklrab))
+            else:
+                gamut_points.add(color.to(ColorSpace.Xyz))
+
+    if space.is_ok():
+        filename = "ok.ply"
+    else:
+        filename = "xyz.ply"
+
+    with open(filename, mode="w", encoding="utf8") as file:
+        file.write("ply\n")
+        file.write("format ascii 1.0\n")
+        if gamut is None:
+            points.write_header(file)
+        else:
+            points.write_header(file, gamut_points)
+        file.write("end_header\n")
+
+        points.write_data(file)
+        if gamut is not None:
+            gamut_points.write_data(file)
+
+
+if __name__ == "__main__":
+    parser = create_parser()
+    options = parser.parse_args()
+    if options.gamut is None:
+        gamut = None
+    else:
+        name = options.gamut.lower()
+        if name == "srgb":
+            gamut = ColorSpace.Srgb
+        elif name == "p3":
+            gamut = ColorSpace.DisplayP3
+        elif name == "rec2020":
+            gamut = ColorSpace.Rec2020
+        else:
+            raise ValueError(f"{name} is not a valid gamut name")
+
+    render(ColorSpace.Xyz, gamut=gamut, planar=options.planar)
+    render(ColorSpace.Oklrab, gamut=gamut, planar=options.planar)