diff -r cd4df75924b7 -r 6ca6e8c647d4 src/ui/canvas.cpp
--- a/src/ui/canvas.cpp	Mon Jul 19 19:28:16 2021 +0300
+++ b/src/ui/canvas.cpp	Mon Jul 19 23:41:52 2021 +0300
@@ -233,6 +233,20 @@
 					renderText(axis.text, *intersection);
 				}
 			}
+			for (const PreviewLayer& previewLayer : this->previewLayers)
+			{
+				painter.setBrush({previewLayer.color});
+				for (const geom::NPolygon& polygon3d : previewLayer.polygons)
+				{
+					QVector<QPointF> points2d;
+					points2d.reserve(polygon3d.points.size());
+					for (const glm::vec3& point : polygon3d.points)
+					{
+						points2d.push_back(this->modelToScreenCoordinates(point));
+					}
+					painter.drawPolygon({points2d});
+				}
+			}
 		}
 	}
 }
@@ -272,3 +286,13 @@
 	const float dot = glm::dot(glm::normalize(this->gridPlane.normal), glm::normalize(cameraDirection));
 	return std::abs(dot) < threshold;
 }
+
+const Canvas::PreviewLayer& Canvas::getPreviewLayer(PreviewLayerName name) const
+{
+	return previewLayers[static_cast<unsigned int>(name)];
+}
+
+Canvas::PreviewLayer& Canvas::modifyPreviewLayer(PreviewLayerName name)
+{
+	return previewLayers[static_cast<unsigned int>(name)];
+}