06-偏置模型.doc

CopyCAD 6. Offsetting Model6. 偏置模型概述当使用球形测头做数字化的时候，点数据是通过球头的中心或尖端来获得的，通过它们来获得表面的数据，要想获得正确的表面，需要按照测头的半径来偏置扫描线。当使用三角形向导的时候，这个操作是自动进行的。使用不同的测头半径偏置多个模型许多模型中的数据是通过多种直径的测头获得的，因为有时候模型上可能存在着大测头所不能测量的区域，通常这些区域都是使用小直径的测头测量所得到。这些扫描线需要根据不同的测头直径使用不同的数值进行偏置，最后将它们联系到一起，再去生成三角模型。当不能使用“三角模型生成向导”的时候，这就是解决的方法。例题 使用菜单“删除” “全部”删除所有存在的模型。 打开Examples2Multiple_ Scans 中的D2.tap文件. 在弹出的“三角模型生成向导”中按“取消”关闭向导。 在弹出的“三角模型生成向导”中按“取消”关闭向导。 打开Examples2Multiple_ Scans中的D3_2.tap文件 在弹出的“三角模型生成向导”中按“取消”关闭向导。 打开Examples2Multiple_ Scans中的D6-2.tap文件 在弹出的“三角模型生成向导”中按“取消”关闭向导。所有的模型都显示在CopyCAD浏览器中, 最后打开的模型是激活的，并且只显示这个模型。这个模型是使用大测头对整个模型的扫描。 D3-1, D2 and D32是使用小测头对细节区域的扫描。 分别激活其他的模型进行查看。四个模型的名称决定了所使用测头的直径， D3_1 and D3_2 used 使用了相同直径的测头，所以在偏置之前先将这两个模型进行合并。 激活模型 D3_1 。 在D3_2上使用鼠标右键打开快捷菜单。 选择“附加到已选模型上”。模型 D3_2附加到模型 D3_1上, 并且在浏览器中创建了一个新的模型。现在偏置这三个模型D2, D3_1+D3_2, 和D6. Make D6 the selected model. Click the Scanline Modelling button on the Top Toolbar. Click the Offset Scanlines button.First we will be using the option Current Model in the same way as before to offset the model D6, and then the option Existing Model (merges offsets) will be used to offset and merge the other two models, using the model off_D6 as a reference. Enter a Probe Diameter of 6.0. Click Apply.A new model is created called off_D6. Select the model D3_1+D3_2. Change the option in the Offset Model dialog box to Existing Model (merges offsets). Enter a Probe Diameter of 3.0.The Existing Model area of the dialog box should now be available. This allows you to pick the model that you want the offset model to be based on. Select the model off_D6 from the pull-down list. Click Apply.A new offset model is created called off_D3_1+D3_2.The model D3_1+D3_2 has been merged with the model off_D6. Although it appears to be no different, since the stepover is the same as the existing model, the areas where the smaller tool was able to scan will now be included in more detail in the original model. Draw the model off_D6 by clicking the lightbulb icon in the CopyCAD Explorer.You should be able to see the difference between the model off_D6 and the merged model off_D3_1+D3_2. We will now repeat the process to merge the model D2 with the merged model off_D3_1+D3_2. Select the model D2 in the CopyCAD Explorer. Leave the option in the Offset Model dialog box as Existing Model (merges offsets). Enter a Probe Diameter of 2.0. Select the model off_D3_1+D3_2 from the list in the Existing Model area of the dialog box. Click Apply A new offset model is created called off_D2.The model D2 has been merged with the model off_D3_1+D3_2. Again it appears at first that there is no change. Draw the model off_ D3_1+D3_2 by clicking the lightbulb icon in t