1、1 北 京 江 达 科 技 发 展 有 限 公 司 CATIA V5 培训逆向设计 CATIA V5 逆向工程 Reverse Engineering 北京江达科技发展有限公司 BEIJING JIANGDA TECHNOLOGY CO., LTD.2 北 京 江 达 科 技 发 展 有 限 公 司 目录 概述 CATIA逆向设计模块介绍 逆向设计流程3 北 京 江 达 科 技 发 展 有 限 公 司 逆向设计流程4 北 京 江 达 科 技 发 展 有 限 公 司 流程 点云数据处理 曲线创建及优化 曲面创建及优化 曲面详细设计（曲面局部设计、曲面匹配处理） 曲面质量分析（与点云误差、曲面表面
2、质量、曲面连接检查）5 北 京 江 达 科 技 发 展 有 限 公 司 点云数据处理6 北 京 江 达 科 技 发 展 有 限 公 司 目录 点云数据测量获取 点云数据读入 多种文件据格式（Ascii、iges、cgo、Atos、Gom-3D、Hyscan、Kreon、 Steinbichler、Stl） 参数设置 数据优化处理（删除、过滤、激活、数据保护） 点云的网格化处理 网格数据编辑（合并、对正） 点云的显示和分析功能 点云数据排列 位置调整（坐标定位） 基于CATIA装配的参数化点云位置调整方法（参数化调整点云坐标系） 练习：1、点云输入；2、网格化处理；3、Dryer；4、点云定位（
3、装配、零件移动）7 北 京 江 达 科 技 发 展 有 限 公 司 点云数据输入(1/2) 点云输入 (1/2): In this application you work from digitized Data. The first job is to import this data inside CATIA 选择文件输入 : You get a standard Windows Dialog box that will allow you to select one (or several) file(s) The displayed files are compliant to the
4、 Format field (*.* to display all file names). 格式 : You have the choice among a wide range of standard formats. A more button shows up according to the selected format, it allows more parameterization Direction and Delimiters apply to scans. Enter this data whenever you know it. Minimal Point Qualit
5、y is used to clean Atos file from invalid points. The quality value of a point lies between 0 and 255 (low to high). Choose a value to ignore points below that value. System applies to the operating system (Unix or Windows NT) used to generate the binary data: select Same if you know you are using t
6、he same operating system as the one used to generate the binary data, Other for the other way, Unknown if you have no indication. Free Edges is used to create or not the scans representing the free edges of a cloud of points. Facets is used to create or not the facets of the imported cloud of points
7、 If the extension of the file you have selected is consistent with the list proposed, the Format field is updated automatically. Otherwise, be careful to enter the correct format in that field. Once you have performed an import operation, Digitized Shape Editor proposes the last entered file path an
8、d format as default. If you click on ., the last entered directory is proposed as default. Ascii : Atos : Stl : Iges :8 北 京 江 达 科 技 发 展 有 限 公 司 点云输入 (2/2) In this application you work from digitized Data. The first job is to import this data inside CATIA 选项 : Sampling：allows to import a certain perc
9、entage of the Digitized data, be careful, this will be done sequentially every x points will be kept. Scale Factor：the scan operation is very often performed on a scaled model, you may want to work on real size model, apply the given scale factor File Unit：your CATIA session is set up for a given un
10、it. The file you import comes from the outside world and may be digitized in another unit. Set up the proper unit before importing the file 预览 : Replace：will replace the current cloud of points by this new one. Update： Will display the cloud of points along with its bounding box. Then use the manipu
11、lators of this box to clip the part of the cloud you import The File unit option is not relevant to the Steinbichler format, nor the Sampling percentage to the Stl format. An element is created in the specification tree, under the name Cloud Import.x. Undo and Redo are available. Digitized Shape Edi
12、tor memorizes the data of the last imported file and proposes them at the next import action.click on ., the last entered directory is proposed as default. If you import several Clouds of points in the same action, the result will be a single Cloud of Point entity 统计 : This check box will allow you
13、to get information in the statistics window (number of points, dimensions) Apply : when you are satisfied with your import parameters, use Apply then OK to create the Cloud Import entity 点云数据输入(2/2)9 北 京 江 达 科 技 发 展 有 限 公 司 Importing a Set of Files The files to import must: have the same format be l
14、ocated under the same directory10 北 京 江 达 科 技 发 展 有 限 公 司 数据处理Remove Points 去除 : This action is used to remove points from the Cloud of Points Selected Part , it can be: Inside Trap: Outside Trap: 选择 : Pick : will allow selection by picking elements on screen. The element type is filtered by the opt
15、ions from Level Trap: Will allow the selection through a contour trap see explanation on trap type. The trap is drawn in a plane but has a depth. Then you may change the trap by the manipulators of the Trap. The deleted points are those that appear in red during the selection By default, as shown ab
16、ove, the trap is displayed in the view plane. It is thus a 2D trap. You can rotate the model to display it as a 3D trap. You can modify the shape of the trap using the green arrows that appear on the edges of the trap. 删除了点就不能再恢复! Activate all and Swap apply only to the current removal action. They
17、can not be used to recall removed points, once you have clicked OK Global : Select all will select the whole Cloud of points Swap will switch the selection by the not selected elements Level: In coordination with Pick can be set, depending to: Point Scan/Grid Cell Cloud Triangle 框选类型 : It can be def
18、ined by a Rectangular or Polygonal contour or by a spline You can create as many areas as you wish by clicking Apply and drawing another trap, until you click OK to validate and exit the action.11 北 京 江 达 科 技 发 展 有 限 公 司 过滤 : Used to decrease the number of points in a Cloud of Points Homogeneous: en
19、ter the value of the Sphere radius, used to filter the points. The filtering sphere is visualized by a green sphere. You can change its position by a simple mouse click at a desired location Each time you click Apply, the cloud of points and the statistics are updated. Once you are satisfied with th
20、e result, click OK to confirm and exit the action 点被隐藏了，不是被删除. 只能对最后一步过滤能 Undo . Leaving the action with Cancel restores the cloud as it was before starting the filtering action. Filtering with a radius equal to 0 cancels ALL filtering actions performed on the cloud of points: 不能过滤点云 tessellated 或 p
21、olygon. When you filter scans or grids, you actually filter points: filtered points are hidden, and new scans or grids are created. Principle : Homogeneous：the sphere passes over the cloud of points, starting on the first point met. All the points that are inside the sphere are then hidden. The sphe
22、re goes to the next remaining point and removes the points that it contains, and so on. In the result, 2 consecutive points will be at least distant from the Sphere radius. Adaptative：will use a local chordal deviation criterion. Statistics will be then displayed, that is : Before application, The n
23、umber of points to be processed. After Application, the number, and the percentage of the remaining points Physical removal : When this option is checked, you will remove the points from your actual Cloud of Points (see Remove menu) Adaptative : The value to enter represents the local chordal deviat
24、ion. This filtering hides more points from the planar areas than from other areas. That way, you can highlight bent areas. 数据处理Filting12 北 京 江 达 科 技 发 展 有 限 公 司 Protecting Characteristic Lines To protect characteristic lines from filtering and removal 13 北 京 江 达 科 技 发 展 有 限 公 司 数据激活 Activate: This a
25、ction is used to define active set of points from a Cloud of Points Inside Trap: Outside Trap: Selected Part , it can be: Selection : Pick : will allow to select by picking elements on screen. The element type is filtered by the options from Level Trap: Will allow the selection through a contour tra
26、p see explanation on trap type. The trap is drawn in a plane but has a depth. Then you may change the trap by the manipulators of the Trap. The activated points are those that appear in red during the selection By default, as shown above, the trap is displayed in the view plane. It is thus a 2D trap
27、. You can rotate the model to display it as a 3D trap. You can modify the shape of the trap using the green arrows that appear on the edges of the trap. Non active points are still in the Clouds of Point element, you can restore it when desired. If displayed as a shaded tessellation, the result will
28、 not be visible. You should display the tessellation as triangles to visualize the result Global : Activate all will activate the whole Cloud of points Swap will switch the activated by the de-activated elements Level: In coordination with Pick can be set to: Point Scan/Grid Digit Cloud Trap Type :
29、It can be either Rectangular or Polygonal trap contour You can create as many areas as you wish by clicking Apply and drawing another trap, until you click OK to validate and exit the action.14 北 京 江 达 科 技 发 展 有 限 公 司 Export: This action creates external files from Clouds of Points, Scans or Tessell
30、ation Save as Type: Ascii free : point coordinates, Scan delimited by G08 and G09. Cgo: the file created is readable in Catia V4 CGO application. Stl: To create a binary file to the Stl format. Only for Tessellation element. IN ASCII mode, the scans exported have the following delimiters: G08 for th
31、e start and G09 for the end. You can export only one element at a time. Therefore, if you want to export several scans, you must use the Grouped into one element option when you create them. You can then use the Import action to recall the file you have created. You can export one element at a time.
32、 You may get a STL file through the menu Save As. ! ! ASCII generated by Digitized Shape Editor/CATIA ! ! Begin Scan Delimitor =G08 ! End Scan Delimitor =G09 ! Point Format =X %f Y %f Z %f ! ! Total number of scans = 1 ! G08(1) X 198.636429 Y -674.889709 Z 108.446014 X 198.636429 Y -675.252319 Z 109
33、.371399 X 198.636429 Y -675.911987 Z 110.685120 X 198.636429 Y -676.812012 Z 112.450233 X 198.636429 Y -677.634827 Z 114.200539 X 198.636429 Y -677.932129 Z 114.842232 CGO: 285 431.198151 -674.281799 107.692230 431.198151 -674.628418 108.223984 431.198151 -675.001831 109.109077 431.198151 -675.63574
34、2 110.533531 431.198151 -676.545776 112.480850 431.198151 -677.638306 115.074150 431.198151 -677.688721 115.194672 431.198151 -677.732605 115.291199 431.198151 -679.014343 118.206978 431.198151 -680.101318 120.927452 STL generated by Digitized Shape Editor/CATIA k then the connections are computed i
35、n a plane normal to that direction16 北 京 江 达 科 技 发 展 有 限 公 司 Offsetting the Mesh Offset：This operation will create an offset of the selected Tessellation. Free Edges : Create Scans, will allow you to create the free edges of your new tessellation as Scan entities. In this release, a clipping problem
36、 may affect the bounding box of the offset tessellation. The offset is computed in the direction of the weighted normals of the points. For better results, you should avoid to enter a high offset value because no control of auto-intersection is performed, no control is performed for disappearing fac
37、ets neither. Offset Value : Enter the value of the offset. Click Apply to check the Result. Use OK to create the new Tessellation.17 北 京 江 达 科 技 发 展 有 限 公 司 Rough Offset To create offsets from complex geometries With a high Granularity value； With a low Granularity value With a positive Offset Dista
38、nce ； With a negative Offset Distance18 北 京 江 达 科 技 发 展 有 限 公 司 Flip Edges Flip Edges To better respect the sharp edges, you may have to flip the common diagonal of 2 triangles. Ergonomic : Select the Flip Edges icon and a cloud (or an activated portion of the cloud). The dialog box is displayed. En
39、ter the value of Flip Angle, This angle identify the candidate triangles. Click Apply. The edges that could be flipped are highlighted in their eventual new position. Click OK to validate. You may first activate only part of the tessellation to focus on some area only The systems computes the angles
40、 of the normal of each adjacent triangle. Using the Flip Angle value, selects the candidate to the flip action (if angle Flip Angle ) On these triangles the system flips edges if the computed energy criteria is not reached Set the ViewCloud Display Options to Flat The value of Depth ranges from 0 to
41、 10 19 北 京 江 达 科 技 发 展 有 限 公 司 Smoothing Meshes To smooth a mesh Coefficient : It balances the effect of the new theoretical position in comparison with the original position . It varies from 0 (the vertex is not moved) to 1 (the vertex is moved to the computed position) Max Deviation: Check this op
42、tion to control the maximum deviation allowed (the displacement will remain under the value set.) Choose Single effect if there is no sharp edge on the mesh to process. Small radii will be erased. The volume of the part will be reduced (contraction towards the center of gravity of the part). Choose
43、Dual effect to reduce the distance between outliers and the surface,and reduce the erasing of small radii. The reduction of the volume of the part is smaller. A large displacement of one vertex inwards may cause the neighboring vertices to move outwards.20 北 京 江 达 科 技 发 展 有 限 公 司 Mesh Cleaner 21 北 京
44、 江 达 科 技 发 展 有 限 公 司 Filling Holes on Meshes Fill Hole：Due to an incomplete cloud, you may have to finish tessellation by fillng some small area. Use the function Fill Hole Ergonomic : Position the cursor on an edge of a hole: a white triangle is displayed. Click on that triangle to fill the hole. D
45、ouble-click to exit the action. Undo is available for this action, but not redo. The holes to fill must be closed. The holes to fill should be small. The centers of gravity of the holes may not be outside the holes. The free edge of a hole may have several loops in it: A computation is first made to create a quadratic shape on top of the hole. Additional vertex may be created before creating the filling facets
