From 963744b15e9508100779717bb174e310aa5e76c5 Mon Sep 17 00:00:00 2001
From: Andrew Barnes <andrew.jaguars@gmail.com>
Date: Wed, 4 Mar 2026 21:12:46 -0500
Subject: [PATCH] doc: add append_trace and orthographic projection examples

Part of #1965.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 doc/python/3d-camera-controls.md            | 23 +++++++++++++++++++++
 doc/python/creating-and-updating-figures.md | 15 ++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/doc/python/3d-camera-controls.md b/doc/python/3d-camera-controls.md
index 749e72f21ee..35830e9ed87 100644
--- a/doc/python/3d-camera-controls.md
+++ b/doc/python/3d-camera-controls.md
@@ -287,6 +287,29 @@ fig.update_layout(scene_camera=camera, title=name)
 fig.show()
 ```
 
+### Orthographic Projection
+
+By default, 3D plots use perspective projection where objects farther from the camera appear smaller. You can switch to orthographic projection, where objects maintain their size regardless of distance. This is useful for technical and engineering visualizations where preserving relative dimensions is important.
+
+```python
+import plotly.graph_objects as go
+import pandas as pd
+
+z_data = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/api_docs/mt_bruno_elevation.csv')
+
+fig = go.Figure(data=go.Surface(z=z_data, showscale=False))
+fig.update_layout(
+    scene_camera=dict(
+        projection=dict(type="orthographic"),
+        eye=dict(x=1.25, y=1.25, z=1.25)
+    ),
+    title=dict(text="Mt Bruno Elevation (Orthographic Projection)"),
+    width=500, height=500,
+    margin=dict(t=40, r=0, l=20, b=20)
+)
+fig.show()
+```
+
 #### Reference
 
 
diff --git a/doc/python/creating-and-updating-figures.md b/doc/python/creating-and-updating-figures.md
index 170fa4d64f2..700dc530f3d 100644
--- a/doc/python/creating-and-updating-figures.md
+++ b/doc/python/creating-and-updating-figures.md
@@ -235,6 +235,21 @@ fig.add_trace(go.Bar(x=[1, 2, 3], y=[1, 3, 2]))
 fig.show()
 ```
 
+The `append_trace()` method can be used to add traces to subplots created with `make_subplots()`. Note that `append_trace()` is deprecated in favor of `add_trace()`, which supports the same `row` and `col` parameters and also returns the figure for method chaining.
+
+```python
+import plotly.graph_objects as go
+from plotly.subplots import make_subplots
+
+fig = make_subplots(rows=1, cols=2)
+
+fig.append_trace(go.Scatter(x=[1, 2, 3], y=[4, 2, 3], name="Trace 1"), row=1, col=1)
+fig.append_trace(go.Bar(x=[1, 2, 3], y=[2, 3, 1], name="Trace 2"), row=1, col=2)
+
+fig.update_layout(title_text="Using append_trace() with Subplots")
+fig.show()
+```
+
 You can also add traces to a figure produced by a figure factory or Plotly Express.
 
 ```python