请点击鼠标左键显示后面内容

请点击鼠标左键显示后面内容 Projection of Polyhedral Solids 平面立体的投影 Summary of Polyhedral Solids 平面 立体概述 Prism 棱柱 Pyramid 棱锥 Exercise 请点击相应标题显示其内容 2 Summary of Polyhedral Solids 平面立体概述 Polyhedral solids: The solids that are surrounded by planes are called polyhedral solids. 平面立体: 完全由平面围成的立体 称为平面立体。 Prisms Polyhedral solids 棱柱 平面立体 Pyramids 棱锥 Intersection lines of edge planes are called edge lines. Intersectionlines of edge planes and bases are called base edge lines. Whendrawing projections of polyhedral solids we are actually drawingthe projections of all edge lines and base edge lines followedby a visibility test of the projected edge lines and base edge lines. 各棱面的交线称为棱线棱面与底面的交 线称为底边画平面立体的投影图实质是画出所有棱线和底边的投影并判别其可见 性。 请点击鼠标左键显示后面内容 3 Prism 棱柱 1. Projection of a prism 棱柱的投 影 Class by the bases of prisms 根据棱柱底面形状可分为:Triangular prism Square prism Pentagonal prism Hexagonal prism三棱柱 四棱柱 五棱柱 六棱柱 …… Draw steps Draw centerlines and datum lines. 画图步骤: 先画中心线和基准线 Add lines for the upper and lower end faces. 再画反映顶部或底部端面形状的视图 Complete three views. 按三等规律画全三视图。 五棱柱的投影演示 请点击鼠标左键显示后面 内容 4 Prism 棱柱2.Getting points on the surface of a prism 棱柱表面上取点 Getting points on surfaces of a prism can be based on the accumulation Method characteristics of edge lines or plane projection. 方法: 棱柱表面上的点可利用棱线或棱面的积聚性投 影求之。 The projection of point is also visible when it is on visible edge or plane.Identification 凡在可见表面及棱线上的点其投影为可见 其投影为可见 判别: The projection of point is not visible when it is on invisible edge or plane. 凡在不可见 表面及棱线上的点其投影则为不可见。请 点 Labeling All invisible points are written in brackets. 击 标注: 对不可见的点加括号以示区别。 鼠 标 Example1. Draw the triangular prism and get points on the surface. 左 键 画三棱柱及表面上各点的三视 图。 显 示 Example2. Draw the square prism and get points on the surface. 后 画四棱 柱及表面上各点的三视图。 面 内 Example3. Draw the pentagonal prism and get points on the surface. 容 画五棱柱及表面上各点的三视图。 5 Pyramid 棱锥 1. Projection of pyramid 棱锥的投影 Class by the bases of a pyramid 根据棱锥底面形状 可分为:Triangular pyramid Square pyramid Pentagonal pyramid Hexagonal pyramid 三 棱锥 四棱锥 五棱锥 六棱锥 ……Draw steps画图步骤:1.Draw symmetry lines and the base of the pyramid. 先画锥底面形状的投影2.Add the vertex of the pyramid. 再画 锥顶点的投影3.Complete three views after adding lines for the side faces. 最后画各棱 线的投影。 请点击鼠标左键显示后面内容 6 Pyramid 棱锥2.Getting points on the surface of a pyramid 棱锥表面取点 Method Draw an auxiliary line or plane going through the point on the pyramid. 方法: 在棱面上过锥顶作一条包含该点的辅助线或 辅助平面。 方法: The projection of point is also visible when it on visible edge or plane.Distinguish 凡在可见表面及棱线上的点其投影为可见; K 判别: 判别: The projection of point is not visible when it on invisible edge or plane. 凡在不可见表面及 棱线上的点其投影则为不可见。Labeling All invisible points are written in brackets. 标 注: 标注: 对不可见的点加括号以示区别。 E Example4. Draw a regular triangular pyramid and get points on the F P surface. 画正三棱锥及表面上各点的三视图。 A Example5. Draw a regular pentagonal pyramid and get points on the C surface. 画正五 棱锥及表面上各点的三视图。 B 请点击鼠标左键显示后面内容Exercise. Complete each drawing by adding the missing detail. 7 补全平面立体及其表面上各点的三投影。 (1)Draw a prism and get points on the surface. 2)Draw a pyramid and get points on the surface. ( 画三棱柱及各点的三投影。 画五棱锥及各点的三投影。 a a b b c c b b a a c c c a b b a c 请点击解答显示其内容本 小 节 结 束 谢谢您的认真学习～ 前一 页 退出 9Example1. Draw the triangular prism and get points on the surface. 画三棱柱 及表面上各点的三视图。 S A B Steps作图步骤: a Draw view of the end faces. a 先 画反映端面形状的视图 b b Complete three views. 再按三等规律画全三视图 Draw all views of points. b 求各点的三投影。 a 请点击鼠标左键显示后面内容 10Example2. Draw the square prism and get points on the surface. 画四棱柱及表面上 各点的三视图。 D C S d d Steps 作图步骤: 作图步骤 (c c Draw view of the end faces. 先画反映端面形状的视图 Complete three views. c 再按三等规律画全三视图 Draw all views of points. 求各点的三投影。 d 请点击鼠标左键显示后面内容 11Example3. Draw the pentagonal prism and get points on the surface. 画五棱柱及表面 上各点的三视图。 f (f F S e e ESteps作图步骤: 作图步骤 (1)Draw the accumulation top view. 先画有积聚性的俯视图 (2)Draw the limit elements. 再画主 视图各棱线的投影 f (3)Draw all views of prism. 根据投影规律求第三投影 e (4) Draw all views of points. 请点击鼠标左键显示后面内容 求各点的三投影。 12Example4. Draw a regular triangular pyramid and get points on the surface. 画正三棱 锥及表面上各点的三视图。 K k k D d (d p e e P E S a b 1’ c ac b A C B a cSteps 作 图步骤: (1)Draw the top view. e 先画俯视图 k (2)Draw the limit elements. p d 1 再画主视图各棱线的投影 (3)Draw all views of pyramid . b 根据投影规律求第三 投影 请点击鼠标左键显示后面内容 (4)Draw all views of point D. (5)Draw all views of point E. 用辅助素线法求D点的三投影 用辅助平面法求E点的三投影。 13Example5. Draw a regular pentagonal pyramid and get points on the surface. 画正五 棱锥及表面上各点的三视图。 A E k k 请 点 K 击 G 鼠 g 标 D g 左 B F (f S p f 键 显 示 b a c e d ae bd c后 CSteps 作图步骤: 作图步骤 a e 面1) Draw the top view. 内 先画俯视图 容2)Draw the limit elements. 再画主视图各棱线的投影。 b g k d f3)Draw all views of pyramid. p 根据投影规律求第三投影 c4)Draw all views of point G. 5)Draw all views of point F. 求G点的三投影用棱线法。 求F点的三投影用 辅助平面法。14 15在图片上点击鼠标左键可以“暂停”或再次“播放” 16在图片上点击 鼠标左键可以“暂停”或再次“播放” 17在图片上点击鼠标左键可以“暂停”或再次“播 放”