From 77d78d28b83622e2cb85e8a72c7d7ab56651d0a3 Mon Sep 17 00:00:00 2001
From: Claus Smitt <claus.smitt@gmail.com>
Date: Tue, 9 May 2023 16:53:15 +0200
Subject: [PATCH] Add OpenCV standard to coordinate frame conversions

Signed-off-by: Claus Smitt <claus.smitt@gmail.com>
---
 kaolin/render/camera/coordinates.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/kaolin/render/camera/coordinates.py b/kaolin/render/camera/coordinates.py
index 32cfa2c5c..2ba99fe72 100644
--- a/kaolin/render/camera/coordinates.py
+++ b/kaolin/render/camera/coordinates.py
@@ -61,3 +61,19 @@ def opengl_coords():
     return torch.tensor([[1, 0, 0],
                          [0, 1, 0],
                          [0, 0, 1]])
+
+def opencv_coords():
+    """OpenCV camera coordinate convension, with Z axis looking outwards from the
+    camera sensor frame::
+
+         X<---------|
+                   /|
+                 Z  |
+                    |
+                    ⌄
+                    Y
+
+    """
+    return torch.tensor([[-1, 0, 0],
+                         [0, -1, 0],
+                         [0, 0, 1]])