diff -r 87c906545fc3 -r 77c819262b7a src/ui/canvas.cpp
--- a/src/ui/canvas.cpp	Sat Feb 29 23:51:03 2020 +0200
+++ b/src/ui/canvas.cpp	Mon Mar 02 11:08:13 2020 +0200
@@ -45,6 +45,7 @@
 		// grid matrix.
 		this->worldPosition = this->gridMatrix * glm::vec4{*this->worldPosition, 1};
 	}
+	/*
 	if (this->worldPosition.has_value())
 	{
 		this->newStatusText("Position: (%1, %2, %3)"_q
@@ -56,6 +57,10 @@
 	{
 		this->newStatusText("Position: <none>"_q);
 	}
+	*/
+	// use a relatively high threshold so that we know when the grid is somewhat perpendicular so we can
+	// automatically change it properly
+	this->newStatusText("Change: %1"_q.arg(isGridPerpendicularToScreen(0.03f) ? "yes" : "no"));
 	PartRenderer::mouseMoveEvent(event);
 }
 
@@ -167,3 +172,23 @@
 	this->gridPlane = geom::planeFromTriangle(triangle);
 	this->gridProgram->setGridMatrix(this->gridMatrix);
 }
+
+/**
+ * @brief Calculates if the screen is perpendicular to the current grid
+ * @return yes no
+ */
+bool Canvas::isGridPerpendicularToScreen(float threshold) const
+{
+	// Find out where the grid is projected on the screen
+	const QPoint gridOrigin2d = pointFToPoint(this->modelToScreenCoordinates(this->gridPlane.anchor));
+	// Find out which direction the camera is looking at the grid origin in 3d
+	const glm::vec3 cameraDirection = glm::normalize(this->cameraLine(gridOrigin2d).direction);
+	// Compute the dot product. The parameters given are:
+	// - the normal of the grid plane, which is the vector from the grid origin perpendicular to the grid
+	// - the direction of the camera looking at the grid, which is the inverse of the vector from the grid
+	//   origin towards the camera
+	// If the dot product between these two vectors is 0, the grid normal is perpendicular to the camera vector
+	// and the grid is perpendicular to the screen.
+	const float dot = glm::dot(glm::normalize(this->gridPlane.normal), glm::normalize(cameraDirection));
+	return std::abs(dot) < threshold;
+}