波峰 物体¶
参考
- 类别
导入 - 导出
- 菜单
OBJ is a widely used de facto standard in the 3D industry. The OBJ format is a popular plain text format, however, it has only basic geometry and material support.
Mesh: vertices, faces, edges, normals, UVs
Separation by groups/objects
Materials/textures
NURBS curves and surfaces
Note
There is no support for mesh vertex colors, armatures, animation, lights, cameras, empty objects, parenting, or transformations.
Note
Blender now only supports complex node-based shading. OBJ having a fixed pipeline-like support of materials, this add-on uses the generic wrapper featured by Blender to convert between both.
Warning
Importing very large OBJ-files (over a few 100mb), can use a lot of RAM.
OBJ's export using Unix line endings
\neven on windows, if you open the files in a text editor it must recognize\nline endings.
属性¶
导入¶
包括¶
- 图像查找
This enables a recursive file search if an image file can't be found.
- 平滑组 Smooth Groups
Surround OBJ smooth groups by sharp edges. Note that these will only be displayed when the Edge Split modifier is enabled.
- 行数（线）
Import OBJ lines and two-sided faces as mesh edges.
变换¶
- Clamp Size
OBJ文件的比例通常差别很大，此设置会将导入的文件固定为固定大小。
- 向前/向上轴
由于许多应用程序使用不同的 "向上" 轴，因此存在转换轴向设置，向前和向上轴——通过映射不同的轴，您可以转换应用程序默认的向上和向前轴之间的旋转。
Blender使用Y轴向前，Z轴向上（因为前视图沿+Y轴方向）。 例如，许多应用程序通常使用Y作为向上轴，在这种情况下，需要使用-Z轴向前，Y轴向上。
几何数据（Geometry）¶
- Split/Keep Vertex Order
When importing an OBJ it's useful to split up the objects into Blender objects, named according to the OBJ-file. However, this splitting loses the vertex order which is needed when using OBJ-files as morph targets. It also loses any vertices that are not connected to a face so this must be disabled if you want to keep the vertex order.
- Split by Object & Split by Group
When importing an OBJ it's useful to split up the objects into Blender objects, named according to the OBJ-file. However, this splitting loses the vertex order which is needed when using OBJ-files as morph targets. It also loses any vertices that are not connected to a face, so this must be disabled if you want to keep the vertex order.
As far as Blender is concerned OBJ Objects and Groups are no difference, since they are just two levels of separation, the OBJ groups are not equivalent to Blender groups, so both can optionally be used for splitting.
导出¶
包括¶
- 选定的物体
只导出选定的物体，否则将导出场景中所有物体。
- Objects as OBJ Objects / Groups
将每个Blender物体导出为OBJ物体。
Note
请注意，就Blender而言，OBJ组和对象之间没有区别，此选项仅包含在区别对待它们的应用进程中。
- 材质组
Create OBJ groups per material.
- 动画
导出从起始帧到结束帧的每一帧为带标号的OBJ文件。请注意这将划分相当长的时间。
变换¶
- 比例|缩放
导出时使用全局比例。
- 路径模式
When referencing paths in exported files you may want some control as to the method used since absolute paths may only be correct on you are own system. Relative paths on the other hand are more portable but mean you have to keep your files grouped when moving about on your local file system. In some cases the path doesn't matter since the target application will search a set of predefined paths anyway so you have the option to strip the path too.
- 自动
对于导出位置的子目录中的文件使用相对路径，对于此外的任何目录使用绝对路径。
- 绝对
使用完整路径。
- 相对
Uses relative paths in every case (except when on a different drive on windows).
- 匹配
依照在Blender中用到的路径使用相对/绝对路径。
- 片段路径
只写入文件名并忽略路径组件。
- 复制
在导出时复制文件并使用相对路径引用它。
- 向前/向上轴
由于许多应用程序使用不同的 "向上" 轴，因此存在转换轴向设置，向前和向上轴——通过映射不同的轴，可以转换应用程序默认向上和向前轴之间的旋转。
Blender使用Y轴向前，Z轴向上（因为前视图沿+Y轴方向看）。 例如，许多应用程序通常使用Y作为向上轴，在这种情况下，需要使用-Z轴向前，Y轴向上。
几何数据（Geometry）¶
- 应用修改器
Export mesh objects as seen in the 3D Viewport with all modifiers applied. Mostly you will want this unless you are exporting a subdivision surface cage.
- 平滑组 Smooth Groups
将Blender的锐边写成平滑的组。
- Bitflag Groups
待补充。
- Write Normals
导出Blender的面和顶点的法线（取决于曲面平滑设置）。
大多数情况下，这不是必需的，因为大多数应用程序将计算自己的法线，但为了匹配Blender的法线贴图纹理，您也需要编写它们。
- Include UVs
从Blender导出活动的UV层坐标。
- Write Materials
导出OBJ时一并写入MTL文件。大多数支持OBJ的导入器也会读取MTL文件。
- 三角面
将四边面导出为两个三面角形。有些程序只有非常基本的OBJ支持，只支持三角面。
- 曲线作为 NURBS
将NURBS曲线写为OBJ NURBS而不是转换为几何体。
- Polygroups
Write faces into OBJ groups based on the meshes vertex group. Note that this does a best guess since a face's vertices can be in multiple vertex groups.
- Keep Vertex Order
Maintain vertex order on export. This is needed when OBJ is used for morph targets.
兼容性¶
NURBS表面，文本3D及变形球在导出时会被转换为网格。
缺失¶
Some of the following features are missing:
NURBS Surfaces -- this could be added but is not widely used.
Advanced Material Settings -- There are material options documented but very few files use them and there are few examples available.
Normals -- Blender ignores normals from imported files, recalculating them based on the geometry.