Maya Python脚本异常：将SBSAR纹理应用至全部对象而非选中对象

问题根源 #

脚本出现这个问题有两个关键原因：

1. 获取目标几何体时用了 cmds.ls(geometry=True)，这行代码会返回场景中所有几何体，而非你选中的对象。
2. 成功找到材质组（shading group）后，没有执行将材质组绑定到目标几何体的代码，逻辑链不完整。

修复后的完整脚本 #

import maya.cmds as cmds 
 
def _connect_place2d(substance_node): 
    """ Connects the place2d texture node to the Substance node """ 
    place_node = cmds.shadingNode('place2dTexture', asUtility=True) 
 
    connect_attrs = [('outUV', 'uvCoord'), ('outUvFilterSize', 'uvFilterSize')] 
 
    for out_attr, in_attr in connect_attrs: 
        cmds.connectAttr('{}.{}'.format(place_node, out_attr), 
                         '{}.{}'.format(substance_node, in_attr)) 
 
def _find_shading_group(node): 
    """ Walks the shader graph to find the shading group """ 
    result = None 
 
    connections = cmds.listConnections(node, source=False) 
 
    if connections: 
        for connection in connections: 
            if cmds.nodeType(connection) == 'shadingEngine': 
                result = connection 
            else: 
                result = _find_shading_group(connection) 
                if result is not None: 
                    break 
 
    return result 
 
def _apply_substance_workflow_to_selected(substance_file, workflow): 
    """ Imports a mesh into Maya and applies the shader from a 
        Substance workflow to it """ 
    # 只获取选中的几何体，过滤非网格对象
    geometry = cmds.ls(selection=True, geometry=True)
    
    # 如果没有选中对象，直接返回避免报错
    if not geometry:
        cmds.warning("请先选中要应用材质的网格对象！")
        return
 
    # Create the substance node and connect the place2d texture node 
    substance_node = cmds.shadingNode('substanceNode', asTexture=True) 
    _connect_place2d(substance_node) 
 
    # Load the Substance file 
    cmds.substanceNodeLoadSubstance(substance_node, substance_file) 
 
    # Apply the workflow 
    cmds.substanceNodeApplyWorkflow(substance_node, workflow=workflow) 
 
    # Acquire the shading group and apply it to the mesh 
    shading_group = _find_shading_group(substance_node)
    
    # 将材质组绑定到选中的几何体
    if shading_group:
        cmds.sets(geometry, forceElement=shading_group)
    else:
        cmds.warning("未找到对应的材质组！")
 
def demo_load_sbsar_workflow(): 
    """ Acquires an sbsar from a file dialog, loading and applying it to 
        any selected mesh """ 
    file_filter = 'Substance (*.sbsar);;' 
 
    files = cmds.fileDialog2(cap='Select a Substance file', fm=1, dialogStyle=2, 
                             okc='Open', fileFilter=file_filter) 
 
    if files: 
        substance_file = files[0] 
        _apply_substance_workflow_to_selected(substance_file, 
                                              cmds.substanceGetWorkflow()) 
 
if __name__ == '__main__': 
    demo_load_sbsar_workflow()

关键修改点 #

1. 获取选中对象：把 geometry = cmds.ls(geometry=True) 改成 geometry = cmds.ls(selection=True, geometry=True)，确保只处理你选中的网格，同时增加了空判断避免无选中时报错。
2. 绑定材质组：在找到shading_group后，添加cmds.sets(geometry, forceElement=shading_group)，强制将材质组分配给选中的对象，补全了材质应用的最后一步。

内容的提问来源于stack exchange，提问作者Rai Rai