obj file structure

Let's look at this in parts:

• The OBJ file format is plain ASCII and allows comments, which is always nice.
• Each line of the file defines some aspect of an object. The kind of information is encoded in the first few characters.
• Each object in the file can be given a name using "g". Here, we called the object "cube."
• A cube has 8 vertices. The 8 lines starting with a "v"...

Full Answer

How to load an OBJ file?

Tutorial 7 : Model loading

• Loading the OBJ. We want loadOBJ to read the file “path”, write the data in out_vertices/out_uvs/out_normals, and return false if something went wrong. ...
• Using the loaded data. Once we’ve got this, almost nothing changes. ...
• Results. Sorry for the lame texture, I’m NOT a good artist : ( Any contribution welcome !
• Other formats/loaders. ...

How to import .OBJ file?

• Import from file (The default.) Imports the normals used in the OBJ file. ...
• From SM group Generates normals from imported smoothing groups. ...
• Auto Smooth Generates smoothing groups based on the angle between faces. ...
• Faceted All faces are assigned to smoothing group 0: that is, no smoothing is applied, and the imported mesh has a faceted appearance.

How to import a .OBJ file into processing?

in sketchup 2017 or 2018 you have to go in window then go to extensions manager and clik on install extentionlearn How to import .obj 3d files in SketchUp.Pl...

How to include .OBJ files into the project?

There include:

• $@: the target filename.
• $*: the target filename without the file extension.
• $<: the first prerequisite filename.
• $^: the filenames of all the prerequisites, separated by spaces, discard duplicates.
• $+: similar to $^, but includes duplicates.
• $?: the names of all prerequisites that are newer than the target, separated by spaces.

How are OBJ files structured?

The OBJ file format is a simple data-format that represents 3D geometry alone — namely, the position of each vertex, the UV position of each texture coordinate vertex, vertex normals, and the faces that make each polygon defined as a list of vertices, and texture vertices.

What does an OBJ file contain?

An OBJ file (. obj) contains information about the geometry of 3D objects. The files are used for exchanging information, CAD, and 3D printing. OBJ files can support unlimited colors, and one file can define multiple objects.

How are OBJ files read?

The first character of each line specifies the type of command. If the first character is a pound sign, #, the line is a comment and the rest of the line is ignored. Any blank lines are also ignored. The file is read in by a tool and parsed from top to bottom just like you would read it.

Do OBJ files contain textures?

As such, OBJs can encode the surface geometry of a 3D model but can also store color and texture information. The format does not store any scene information (such as light position) or animations, however.

What is the difference between OBJ and STL?

STL files store objects as sets of vertices joined by edges to make triangular faces. OBJ files store 3D information as a list of vertices joined by edges, and unlike STLs, they support polygonal faces that allow for a closer representation of the original geometry.

What can you do with an OBJ file?

An OBJ file is a standard 3D image format that can be exported and opened by various 3D image editing programs. It contains a three-dimensional object, including 3D coordinates, texture maps, polygonal faces, and other object information. OBJ files may also store references to one or more .

How do I edit OBJ files?

Another Microsoft app that you can try to edit OBJ files is 3D Builder. Like Paint 3D, it is also a native 3D modeling app in Windows 10. Windows 11 users can download and install this free app from Microsoft Store. You can simply open an OBJ model and then modify it using several 3D modeling tools.

What is the difference between OBJ and FBX?

Generally speaking, FBX is far more complex than OBJ - it supports mesh data, color data, vertex painting, animations, lighting, rigs, joints, skinning, cameras, etc. OBJ is much simpler, supporting just 3D objects and their geometry. For Roblox specifically - if you're only working with meshes then OBJ should be fine.

What does F mean in OBJ file?

a face ofThe f indicates a face of the model (e.g., a triangle or a quad). The numbers are indices into the vertex list that indicate the way you should join it to form the face.

Can Blender Open .OBJ files?

Luckily, Blender offers a wide range of file formats (e.g. OBJ, FBX, 3DS, PLY, STL, etc.) that can be used to import and export.

How do I color an OBJ file?

To enable color on the model, follow the steps below:Go into GrabCAD preferences and click on the GrabCAD Labs tab.Next click to enable OBJ file import with colors and textures.Once the setting is saved, reimport the same file. Now your model has an array of colors and textures.

Does OBJ support animation?

No, . obj files do not support animation.

What is an obj file?

OBJ is a vector file, which makes the defined objects scalable. There’s no maximum file size.

Can you edit an OBJ file by hand?

Technically, since the OBJ format is simple (the data is uncompressed, and is in ASCII), you could conceivably edit a file by hand (but this doesn’t happen often).

Can an OBJ file be referenced to multiple MTL files?

To reference an MTL file, use the following syntax in the OBJ file: OBJ files can reference multiple MTL files, which allows the ability to add numerous features to objects. Multiple OBJ files can reference the same MTL file. Each MTL file may contain one or more color and texture definitions.

Is OBJ better than STL?

Like all file formats, OBJ files do have some limitations, and it may be better to use a different format. Those scenarios include: Not all printers support OBJ, so STL may be a better option. Either way, check to make sure the printer you want to use supports your file format.

Can Blender import OBJ files?

It can import OBJ files and convert them to Blender’s format (called a BLEND file). You can also add OBJ files to existing BLEND files. Blender can also export files in the OBJ format, but because BLEND files have more data, not everything will be available in the exported file.

Is OBJ open source?

OBJ has a simple file structure compared to COLLOADA. OBJ is open source, and it’s a good bridge for converting files to other formats if you can’t convert between the two directly.

Can you add visual information to an OBJ file?

OBJ files don’t contain visual information, but you can add this information to the objects in the OBJ file by referencing a support file. Here’s an example of an MTL file from Florida State University:

Material template library

A single .mtl file may define multiple materials. Materials are defined one after another in the file, each starting with the newmtl command:

See also

PLY (file format) is an alternative file format offering more flexibility than most stereolithography applications.

Can you edit an obj file?

The OBJ file format is a text file format, which means you can edit OBJ files in a text editor if you are hard-core. Unfortunately, the original specification didn't seem to state what the end of line character should be, so some tools use carriage-returns and some use linefeeds. You may have to convert the end of line characters depending on which ...

Does Poser 3 use OBJ?

Poser 3 only uses a subset of the full OBJ file format. Here's everything you need to know about OBJ files if your just using Poser. This document leaves out all non- Poser usable commands and options so you aren't confused about things you'll never need. I recommend reading this tutorial, then opening up a couple OBJ files and checking them out, ...

About

Wavefront OBJ (.obj) is a ASCII file format for representing 3D mesh geometries - namely the position of vertices, texture coordinates, normals and the faces of each polygon defined as a list of vertices.

MTL File Format Basics

Material Template Library (MTL) is an ASCII file format defined by Wavefront Technologies to specify material and light reflecting properties. MTL files are typically accompanied by and referenced from OBJ files that define geometry upon which the materials of the MTL file are mapped. A more detailed look at this standard is available here.

See Also

Generating a sphere as a 3D mesh - shows an example of generating a OBJ file using C code.

Links

Wavefront .obj file - Wikipedia - gives a great little summary of the main keywords.

What is a non blank line in an OBJ file?

Each non-blank line begins with a keyword and may be followed on the same line with the data for that keyword. Lines are read and processed until the end of the file. Lines can be logically joined with the line continuation character ( ) at the end of a line. The following keywords may be included in an OBJ file.

Do OBJ files have a header?

OBJ files do not require any sort of header, although it is common to begin the file with a comment line of some kind. Comment lines begin with a hash mark (#). Blank space and blank lines can be freely added to the file to aid in formatting and readability.

Overview

File format

Anything following a hash character (#) is a comment.
An OBJ file may contain vertex data, free-form curve/surface attributes, elements, free-form curve/surface body statements, connectivity between free-form surfaces, grouping and display/render attribute information. The most common elements are geometric vertices, texture coordinates, vertex normals and polygonal faces:

Material template library

See also

External links