.obj 文件中的人脸是什么？它们是如何工作的？

如何解决.obj 文件中的人脸是什么？它们是如何工作的？

我有 this .obj 文件。它是 Mini-Cooper 的模型。我将所有顶点和面提取到如下所示的列表中：

vertices = [(14.82,-22.56,25.83),(25.38,29.02,15.87),(-31.71,-57.05,19.29),(-27.95,46.76,17.98),(-25.44,47.58,3.38),(33.63,48.57,7.97),(-30.81,32.23,22.08),(-14.13,29.34,27.43),(3.94,47.76,52.66),-69.78,16.93),(29.55,4.96,38.49),(33.31,42.57,13.42),(27.8,8.16,38.6),(-26.77,46.93,2.27),(-30.21,-80.45,24.88),(-33.48,40.09,23.68),(33.29,51.84,13.67),(-9.08,67.39,17.91),(25.27,31.68,5.62),(-30.2,-36.77,39.17)]

faces = [('1962/1/1962','1958/1/1958','1957/541/1957'),('1957/541/1957','1961/541/1961','1962/1/1962'),('1960/3202/1960','1959/542/1959','1963/542/1963'),('1963/542/1963','1964/3202/1964','1960/3202/1960'),('1966/543/1966','1962/1/1962','1961/541/1961'),('1961/541/1961','1965/544/1965','1966/543/1966'),('1964/3202/1964','1963/542/1963','1967/546/1967'),('1967/546/1967','1968/545/1968','1964/3202/1964'),('1970/543/1970','1966/543/1966','1965/544/1965'),('1965/544/1965','1969/544/1969','1970/543/1970'),('1968/545/1968','1967/546/1967','1971/546/1971'),('1971/546/1971','1972/545/1972','1968/545/1968'),('1985/547/1985','1970/543/1970','1969/544/1969'),('1969/544/1969','1984/550/1984','1985/547/1985'),('1993/551/1993','1991/551/1991','1993/551/1993'),('1958/1/1958','1994/548/1994'),('1994/548/1994','1992/548/1992','1958/1/1958'),'1995/550/1995','1965/544/1965')]

这些只是前 20 个。我编写了一个渲染程序，当我放入顶点时，它显示如下：

它看起来像是汽车的自上而下的视图，这是有道理的。我是 3d 模型的完整初学者。如何添加人脸？我的程序可以从 3 个点绘制三角形，但面有很大的数字，所以它们不能只是坐标。它们是什么，我如何从它们中获取三角形？

解决方法

我想用一些代码来扩展我的评论，展示如何解析某些文件，然后用顶点索引替换实际坐标：

def main():

    import re

    flt = r"-?[\d\.]+"
    vertex_pattern = r"v\s+(?P<x>{})\s+(?P<y>{})\s+(?P<z>{})".format(flt,flt,flt)
    face_pattern = r"f\s+((\d+/\d+/\d+\s*){3,})"

    vertices = []
    faces = []

    with open("alfa147.obj.txt","r") as file:
        for line in map(str.strip,file):
            match = re.match(vertex_pattern,line)
            if match is not None:
                vertices.append(tuple(map(float,match.group("x","y","z"))))
                continue
            match = re.match(face_pattern,line)
            if match is not None:
                faces.append(tuple(tuple(map(int,vertex.split("/"))) for vertex in match.group(1).split()))

    print(f"The first face has {len(faces[0])} vertices:")
    for vertex in faces[0]:
        print(vertex)

    print("\nWe do not care about the texture coordinate indices or normal indices,so we get the three vertex indices:")
    for vertex in faces[0]:
        print(vertex[0])

    print("\nAfter substituting the indices for their values,the face is made up of these coordinates:")
    for vertex in faces[0]:
        print(vertices[vertex[0]-1]) # -1 because in the OBJ spec,collections start at index 1 rather than 0 

    return 0


if __name__ == "__main__":
    import sys
    sys.exit(main())

输出：

The first face has 3 vertices:
(1962,1,1962)
(1958,1958)
(1957,541,1957)

We do not care about the texture coordinate indices or normal indices,so we get the three vertex indices:
1962
1958
1957

After substituting the indices for their values,the face is made up of these coordinates:
(-4.29133,47.755795,51.585678)
(-4.29133,47.716423,52.661789)
>>>