From 9bfb1f787326100b01165f8b56b8f171e19c56c5 Mon Sep 17 00:00:00 2001
From: Anders Syvertsen <andesyv@gmail.com>
Date: Mon, 23 Aug 2021 18:41:08 +0200
Subject: [PATCH] Added a matrix decomposition utility function
---
src/Viewer.cpp | 19 +++++++++++++++++++
src/Viewer.h | 12 ++++++++++--
2 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/src/Viewer.cpp b/src/Viewer.cpp
index cfbedfd..4c0ea85 100644
--- a/src/Viewer.cpp
+++ b/src/Viewer.cpp
@@ -452,3 +452,22 @@ void Viewer::mainMenu()
ImGui::EndMenu();
}
}
+
+namespace minity
+{
+ void matrixDecompose(const glm::mat4& matrix, glm::vec3& translation, glm::mat4& rotation, glm::vec3& scale)
+ {
+ translation = glm::vec3{matrix[3]};
+ glm::mat3 inner = glm::mat3{matrix};
+
+ scale.x = glm::length(inner[0]);
+ scale.y = glm::length(inner[1]);
+ scale.z = glm::length(inner[2]);
+
+ inner[0] /= scale.x;
+ inner[1] /= scale.y;
+ inner[2] /= scale.z;
+
+ rotation = glm::mat4{inner};
+ }
+}
diff --git a/src/Viewer.h b/src/Viewer.h
index 3217d1d..554cf53 100644
--- a/src/Viewer.h
+++ b/src/Viewer.h
@@ -14,7 +14,6 @@
namespace minity
{
-
class Viewer
{
public:
@@ -78,5 +77,14 @@ namespace minity
bool m_saveScreenshot = false;
};
-
+ /**
+ * @brief Performs standard decomposition of a transformation matrix into translation, rotation and scale parts respectively.
+ * Note: The out rotation is an affine space rotation matrix, meaning only the inner 3x3 part affects rotation and the rest is the identity matrix.
+ * @see https://math.stackexchange.com/questions/237369/given-this-transformation-matrix-how-do-i-decompose-it-into-translation-rotati
+ * @param matrix The matrix to decompose
+ * @param translation Out parameter for translation
+ * @param rotation Out parameter for rotation
+ * @param scale Out parameter for scale
+ */
+ void matrixDecompose(const glm::mat4& matrix, glm::vec3& translation, glm::mat4& rotation, glm::vec3& scale);
}
\ No newline at end of file
--
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