           if (!drawPoint) {
                    return;
                }
                const lastPointIndex = prepareMoving ? tempPositions.length / 3 : tempPositions.length / 3 - 1;//如果是准备moving鼠标，则增加一个点，否则替换最后一个点
                tempPositions[lastPointIndex * 3] = drawPoint[0];
                tempPositions[lastPointIndex * 3 + 1] = drawPoint[1];
                tempPositions[lastPointIndex * 3 + 2] = drawPoint[2];
                if (drawingState === 'd