Create a proper raw mesh example (#1957)

Cargo.lock

@@ -8305,9 +8305,7 @@ name = "raw_mesh"
 version = "0.27.0-alpha.8+dev"
 dependencies = [
  "anyhow",
- "bytes",
  "clap",
- "gltf",
  "rerun",
 ]
 

examples/python/raw_mesh/README.md

@@ -6,12 +6,11 @@ thumbnail_dimensions = [480, 480]
 channel = "release"
 -->
 
-Demonstrates logging of raw 3D mesh data (so-called "triangle soups") with simple material properties and their transform hierarchy.
+Demonstrates how to construct and log raw 3D mesh data (so-called "triangle soups") programmatically from scratch.
 
-Note that while this example loads GLTF meshes to illustrate [`Mesh3D`](https://rerun.io/docs/reference/types/archetypes/mesh3d)'s abilitites, you can also send various kinds of mesh assets
-directly via [`Asset3D`](https://rerun.io/docs/reference/types/archetypes/asset3d).
+This example shows how to create mesh geometry by manually defining vertices, normals, colors, and texture coordinates for various geometric primitives, each demonstrating different features of the [`Mesh3D`](https://rerun.io/docs/reference/types/archetypes/mesh3d) archetype.
 
-<!-- TODO(#1957): How about we load something elseto avoid confusion? -->
+If you want to log existing mesh files (like GLTF, OBJ, STL, etc.), use the [`Asset3D`](https://rerun.io/docs/reference/types/archetypes/asset3d) archetype instead.
 
 <picture data-inline-viewer="examples/raw_mesh">
   <img src="https://static.rerun.io/raw_mesh/d5d008b9f1b53753a86efe2580443a9265070b77/full.png" alt="">
@@ -25,43 +24,77 @@ directly via [`Asset3D`](https://rerun.io/docs/reference/types/archetypes/asset3
 [`Transform3D`](https://www.rerun.io/docs/reference/types/archetypes/transform3d), [`Mesh3D`](https://www.rerun.io/docs/reference/types/archetypes/mesh3d)
 
 ## Background
-Raw 3D mesh data refers to the basic geometric representation of a three-dimensional object, typically composed of interconnected triangles.
-These triangles collectively form the surface of the object, defining its shape and structure in a digital environment.
-Rerun was employed to visualize and manage this raw mesh data, along with its associated simple material properties and transform hierarchy.
+Raw 3D mesh data refers to the basic geometric representation of a three-dimensional object, typically composed of interconnected triangles (vertices, edges, and faces). This example demonstrates how to construct such data programmatically without loading external files.
 
+## Geometric Primitives
+
+The example generates several geometric primitives, each showcasing different `Mesh3D` features:
+
+### Cube (per-vertex colors)
+A cube where each face has a different color, demonstrating how to use `vertex_colors` for per-vertex coloring.
+
+### Pyramid (UV texture)
+A four-sided pyramid with UV texture coordinates and a procedurally generated checkerboard texture, demonstrating `vertex_texcoords` and `albedo_texture`.
+
+### Sphere (smooth shading)
+A UV sphere with vertex normals for smooth shading, demonstrating `vertex_normals` and `albedo_factor`.
+
+### Icosahedron (flat shading)
+A 20-sided regular polyhedron rendered without vertex normals, resulting in flat-shaded faces.
 
 ## Logging and visualizing with Rerun
 
 The visualizations in this example were created with the following Rerun code:
 
-### 3D mesh data
-The raw 3D mesh data are logged as [`Mesh3D`](https://www.rerun.io/docs/reference/types/archetypes/mesh3d) objects, and includes details about vertex positions, colors, normals, texture coordinates, material properties, and face indices for an accurate reconstruction and visualization.
+### Cube with vertex colors
+```python
+rr.log(
+    "world/cube",
+    rr.Mesh3D(
+        vertex_positions=cube["vertex_positions"],
+        vertex_colors=cube["vertex_colors"],
+        triangle_indices=cube["triangle_indices"],
+    ),
+)
+```
 
+### Pyramid with texture
 ```python
 rr.log(
-    path,
+    "world/pyramid",
     rr.Mesh3D(
-        vertex_positions=mesh.vertices,
-        vertex_colors=vertex_colors,
-        vertex_normals=mesh.vertex_normals,
-        vertex_texcoords=vertex_texcoords,
-        albedo_texture=albedo_texture,
-        triangle_indices=mesh.faces,
-        albedo_factor=albedo_factor,
+        vertex_positions=pyramid["vertex_positions"],
+        vertex_texcoords=pyramid["vertex_texcoords"],
+        albedo_texture=texture,
+        triangle_indices=pyramid["triangle_indices"],
     ),
 )
 ```
-Through Rerun's [`Transform3D`](https://www.rerun.io/docs/reference/types/archetypes/transform3d) archetype, essential details are captured to ensure precise positioning and orientation of meshes within the 3D scene.
+
+### Sphere with smooth shading
 ```python
 rr.log(
-    path,
-    rr.Transform3D(
-        translation=trimesh.transformations.translation_from_matrix(world_from_mesh),
-        mat3x3=world_from_mesh[0:3, 0:3],
+    "world/sphere",
+    rr.Mesh3D(
+        vertex_positions=sphere["vertex_positions"],
+        vertex_normals=sphere["vertex_normals"],
+        albedo_factor=np.array([100, 150, 255, 255], dtype=np.uint8),
+        triangle_indices=sphere["triangle_indices"],
     ),
 )
 ```
 
+### Icosahedron with flat shading
+```python
+rr.log(
+    "world/icosahedron",
+    rr.Mesh3D(
+        vertex_positions=icosahedron["vertex_positions"],
+        albedo_factor=np.array([255, 180, 100, 255], dtype=np.uint8),
+        triangle_indices=icosahedron["triangle_indices"],
+    ),
+)
+```
 
 ## Run the code
 To run this example, make sure you have the Rerun repository checked out and the latest SDK installed:
@@ -79,11 +112,11 @@ To experiment with the provided example, simply execute the main Python script:
 ```bash
 python -m raw_mesh # run the example
 ```
-You can specify scene:
+You can customize the sphere subdivisions for more or less detail:
 ```bash
-python -m raw_mesh --scene {lantern,avocado,buggy,brain_stem}
+python -m raw_mesh --sphere-subdivisions 64
 ```
-If you wish to customize it, explore additional features, or save it use the CLI with the `--help` option for guidance:
+If you wish to explore additional features or save it, use the CLI with the `--help` option for guidance:
 ```bash
 python -m raw_mesh --help
 ```

examples/python/raw_mesh/pyproject.toml

@@ -2,7 +2,7 @@
 name = "raw_mesh"
 version = "0.1.0"
 readme = "README.md"
-dependencies = ["numpy", "requests>=2.31,<3", "rerun-sdk", "trimesh"]
+dependencies = ["numpy", "rerun-sdk"]
 
 [project.scripts]
 raw_mesh = "raw_mesh.__main__:main"