d.drawImage(img, 0, 0);
						// Values between 0 and 1 in the height-field/texture space
						const { x, y } = coords.mapSpace;
						visibleCanvasContext2d.fillRect(x * IMAGE_SIZE - 3, y * IMAGE_SIZE - 3, 6, 6);
						overlayMap.needsUpdate = true;

						// Convert the HTML OptionSelect to a float value
						const delta = parseFloat(raiseLower.value);
						// Alter the terrain by this amount
						changeTerrainShape(x, y, delta);

						// select a region sure to encompass all changed spheres. This co