1. What is the model origin?
The model origin is a concept in three-dimensional modeling, which refers to a reference point determined in a virtual three-dimensional space. The model origin is usually located at the geometric center of the model or the center of the basic component. as the picture shows:
You can see that the origin of the model is at the geometric center of the model
2. The role of the model origin
Now that we know what the model origin is, what are the functions of the model origin?
The following are the points of action of the model origin:
- Position determination: The model origin can help determine the position of the model in three-dimensional space. By moving the origin, you can place the model where you need it, ensuring that operations such as placing, rotating, and scaling it throughout the scene work properly.
- Coordinate system: The model origin determines the coordinate system of the model, which is the datum axis of the three-dimensional space. This makes the model more convenient when interacting with other objects, laying out and positioning it.
- Animation and transformation: When performing animation and transformation operations, the model origin plays a key role as a reference point. All translation, rotation, scaling and other operations are performed based on the model origin.
- Export and import: When exporting or importing model files, the model origin can help maintain the consistency of the model between different software. It can become a reference point for data exchange between different software.
3. Problems that may be caused by the model origin
When working, if the model origin is not at the geometric center, it may cause some problems, including:
- Difficulty in positioning and alignment: If the model origin is not in the geometric center, it will be difficult to accurately position and align the model. The geometric center is often the most intuitive reference point when it comes to aligning a model with other models or scene elements. If the origin is incorrectly positioned, the model may not be accurately positioned.
- Transformation out of control: The model origin plays a key role when performing transformation operations (such as translation, rotation, scaling). If the origin is incorrectly positioned, the transform operation may not perform as expected, causing unexpected results in the model. For example, when trying to translate an entire model, only part of the model may actually be translated, rather than the entire model.
- Animation and Constraint Anomalies: In animation and constraint systems, the model origin is often used as the attachment point for bones or controllers. If the origin position is incorrect, it may cause abnormal animation motion or invalid constraints. This can make the animation process difficult and affect the model's real-time interactive performance.
- Import and export issues: When exporting a model from one software to another, or importing a model from a 3D modeling software into a game engine, the origin position may change. If the model origin is not at the geometric center, the import and export process may be offset or misaligned, resulting in the model not being correctly placed or aligned to the target environment.
Therefore, it is important to ensure that the model origin is located near the geometric center. This helps to smoothly perform operations such as positioning, transformation, animation, import and export of the model, improves work efficiency, and avoids potential problems.
4. How to set the model origin
So how to set the model origin?
Most 3D modeling software on the market has this function, but most modeling software is PC software, which requires the installation of related programs and dependent programs. The software is large and complex to install. Even after the installation is successful, due to the professionalism and complexity of the software, most people do not know how to use it or cannot use it proficiently, which is time-consuming and labor-intensive.
The GLTF editor is different. It is an online tool that does not require installation or registration. It does not have any dependencies. It can be used by opening a browser. The operation is very simple and convenient, which can greatly improve the user's work efficiency. Next, we will introduce how to use the GLTF editor to reset the origin of the model.
Before modification, we use Blender to look at the origin position of the original model, as shown in the figure below:
The position of the model origin is at the bottom right side of the model
We can add the model to the scene to test the rotation operation of the model. We can intuitively feel the role of the model origin. We will use the NSDT scene editor to test it.
We see that the model is rotating along a straight line perpendicular to the origin of the bottom right side of the model.
Next, we import the model into the GLTF editor to reset the model origin, click the [Modify Center Point] button, directly modify the X, Y, and Z values in the pop-up box to 0 (the geometric center of the model), and click Save. The model origin is reset successfully.
Next, we import the model after resetting the origin into the NSDT scene editor , and then rotate the model to see the effect.
You can see that the model is rotating along the center of the set that is perpendicular to the model, indicating that the model origin has indeed been reset successfully.
5 Conclusion
In addition to modifying the model origin, the GLTF editor also supports the following functions:
Model material merging : Merge materials used in multiple models into one or a few shared materials. This process can be performed in 3D computer graphics to optimize the model's rendering performance and reduce memory footprint.
Model material modification: Modify the material properties of the model to control the model's appearance, reflection characteristics and lighting effects.
As well as the modification of model size, rotation angle and basic attributes, this part will be described in a future article.
Original link: How to quickly reset the model origin in the GLTF editor (mvrlink.com)