pythonocc基础使用：模型信息获取（装配关系，材料，颜色）XCAF

谁借莪１个温暖的怀抱￠ 2022-01-23 04:51 720阅读 0赞

占坑。。。  
[https://www.opencascade.com/doc/occt-7.3.0/overview/html/occt\_user\_guides\_\_xde.html][https_www.opencascade.com_doc_occt-7.3.0_overview_html_occt_user_guides_xde.html]

[https://www.opencascade.com/doc/occt-7.1.0/overview/html/occt\_user\_guides\_\_iges.html][https_www.opencascade.com_doc_occt-7.1.0_overview_html_occt_user_guides_iges.html]

he Extended Data Exchange (XDE) module allows extending the scope of exchange by translating additional data attached to geometric BREP data, thereby improving the interoperability with external software.

Data types such as **colors**, **layers**, **assembly descriptions** and **validation properties** (i.e. center of gravity, etc.) are supported. These data are stored together with shapes in an XCAF document. It is also possible to add a new types of data taking the existing tools as prototypes.

OCC.XCAFDoc
    XCAFDoc_DocumentTool

Definition of general structure of DECAF documentand tools to work with itThe document is composed of sections, each sectionstoring its own kind of data and managing by correspondingtoolSome properties can be attached directly to shapes. These properties are:\* Name (the standard definition from OCAF) - class TDataStd\_Name\* Centroid (for the validation of transfer) - class XCAFDoc\_Centroid\* Volume (for the validation of transfer) - class XCAFDoc\_Volume\* Area (for the validation of transfer) - class XCafDoc\_AreaManagement of these attributes is realized by OCAF. For gettingthe attributes attached to a label the method classTDF\_Label::FindAttribute() should be used.

![在这里插入图片描述][20190602161531335.png]此张图片里提到了TDF，后面该代码也使用到了TDF的东西。。

from OCC.Core.TCollection import TCollection_ExtendedString
    
    from OCC.Core.TDocStd import TDocStd_Document
    from OCC.Core.XCAFDoc import (XCAFDoc_DocumentTool_ShapeTool,
                                  XCAFDoc_DocumentTool_ColorTool,
                                  XCAFDoc_DocumentTool_LayerTool,
                                  XCAFDoc_DocumentTool_MaterialTool)
    from OCC.Core.STEPCAFControl import STEPCAFControl_Reader
    from OCC.Core.IFSelect import IFSelect_RetDone
    from OCC.Core.TDF import TDF_LabelSequence
    
    from OCC.Display.SimpleGui import init_display
    
    filename = 'a380_asm.stp'
    _shapes = []
    
    # create an handle to a document
    doc = TDocStd_Document(TCollection_ExtendedString("pythonocc-doc"))
    
    # Get root assembly
    shape_tool = XCAFDoc_DocumentTool_ShapeTool(doc.Main())
    l_colors = XCAFDoc_DocumentTool_ColorTool(doc.Main())
    l_layers = XCAFDoc_DocumentTool_LayerTool(doc.Main())
    l_materials = XCAFDoc_DocumentTool_MaterialTool(doc.Main())
    
    step_reader = STEPCAFControl_Reader()
    step_reader.SetColorMode(True)
    step_reader.SetLayerMode(True)
    step_reader.SetNameMode(True)
    step_reader.SetMatMode(True)
    
    status = step_reader.ReadFile(filename)
    if status == IFSelect_RetDone:
        step_reader.Transfer(doc)
    
    labels = TDF_LabelSequence()
    color_labels = TDF_LabelSequence()
    
    shape_tool.GetFreeShapes(labels)
    
    print("Number of shapes at root :%i" % labels.Length())
    for i in range(labels.Length()):
        sub_shapes_labels = TDF_LabelSequence()
        print("Is Assembly :", shape_tool.IsAssembly(labels.Value(i+1)))
        sub_shapes = shape_tool.GetSubShapes(labels.Value(i+1), sub_shapes_labels)
        print("Number of subshapes in the assemly :%i" % sub_shapes_labels.Length())
    l_colors.GetColors(color_labels)
    
    print("Number of colors=%i" % color_labels.Length())
    for i in range(color_labels.Length()):
        color = color_labels.Value(i+1)
        print(color.DumpToString())
    
    for i in range(labels.Length()):
        label = labels.Value(i+1)
        a_shape = shape_tool.GetShape(label)
        m = l_layers.GetLayers(a_shape)
        _shapes.append(a_shape)
    
    #
    # Display
    #
    display, start_display, add_menu, add_function_to_menu = init_display()
    display.DisplayShape(_shapes, update=True)
    start_display()

Is Assembly : True
    Number of subshapes in the assemly :0
    Number of colors=4
    0:1:2:1	NOT imported; NOT modified; NO attribute modified; has 3 attributes.
    	XCAFDoc_Color	Trans. 0; Valid;	ID = efd212f0-6dfd-11d4-b9c8-0060b0ee281b
    	TDataStd_Name	Trans. 0; Valid;	ID = 2a96b608-ec8b-11d0-bee7-080009dc3333
    	TDataStd_TreeNode	Trans. 0; Valid;	ID = efd212e5-6dfd-11d4-b9c8-0060b0ee281b
    
    0:1:2:2	NOT imported; NOT modified; NO attribute modified; has 4 attributes.
    	XCAFDoc_Color	Trans. 0; Valid;	ID = efd212f0-6dfd-11d4-b9c8-0060b0ee281b
    	TDataStd_Name	Trans. 0; Valid;	ID = 2a96b608-ec8b-11d0-bee7-080009dc3333
    	TDataStd_TreeNode	Trans. 0; Valid;	ID = efd212e6-6dfd-11d4-b9c8-0060b0ee281b
    	TDataStd_TreeNode	Trans. 0; Valid;	ID = efd212e5-6dfd-11d4-b9c8-0060b0ee281b
    
    0:1:2:3	NOT imported; NOT modified; NO attribute modified; has 3 attributes.
    	XCAFDoc_Color	Trans. 0; Valid;	ID = efd212f0-6dfd-11d4-b9c8-0060b0ee281b
    	TDataStd_Name	Trans. 0; Valid;	ID = 2a96b608-ec8b-11d0-bee7-080009dc3333
    	TDataStd_TreeNode	Trans. 0; Valid;	ID = efd212e5-6dfd-11d4-b9c8-0060b0ee281b
    
    0:1:2:4	NOT imported; NOT modified; NO attribute modified; has 3 attributes.
    	XCAFDoc_Color	Trans. 0; Valid;	ID = efd212f0-6dfd-11d4-b9c8-0060b0ee281b
    	TDataStd_Name	Trans. 0; Valid;	ID = 2a96b608-ec8b-11d0-bee7-080009dc3333
    	TDataStd_TreeNode	Trans. 0; Valid;	ID = efd212e5-6dfd-11d4-b9c8-0060b0ee281b
    ``

[https_www.opencascade.com_doc_occt-7.3.0_overview_html_occt_user_guides_xde.html]: https://www.opencascade.com/doc/occt-7.3.0/overview/html/occt_user_guides__xde.html
[https_www.opencascade.com_doc_occt-7.1.0_overview_html_occt_user_guides_iges.html]: https://www.opencascade.com/doc/occt-7.1.0/overview/html/occt_user_guides__iges.html
[20190602161531335.png]: /images/20220123/dcef15053bce406482047908946406ab.png