LoD Calculator

LoDCalculator is a free and open-source add-on for Blender that allows for the classification of 3D models based on their level of detail (LoD). This software has been designed to enable universal classification of 3D models, regardless of their scale or size, in a precise and unambiguous way and user-friendly. LoDCalculator is intended to classify realistic 3D models based on their LoD, but due to its open-source nature, its code can be modified to adapt its design for other types of 3D models.

OBJECTIVES

The purpose of this project is to create a method for classifying 3D models that allows for a clear and universal classification of 3D models, while also being accessible and user-friendly.

  • ACCESSIBILITY

LoDCalculator has been developed as a free and open-source add-on for Blender. This add-on integrates into the Blender interface and is controlled with a single button. Additionally, it features a user error notification system. This guarantees the accessibility of the system not only from an economic perspective, being free and open-source, but also in terms of usability, as it is very easy to use and implemented in one of the most popular open-source 3D modeling software.

  • UNAMBIGUOUS CLASSIFICATION

LoDCalculator operates with a multi-threshold system that works with objective data extracted from 3D models. By not using any semantic criteria for threshold separation, it ensures that the segmentation according to LoD is unambiguous.

  • UNIVERSALITY OF THE SYSTEM

LoDCalculator is designed to analyze any type of 3D model in a comparable way, regardless of its complexity or size, always analyzing relative data from the 3D model. In this sense, its only requirement is that it is designed to analyze 3D models based on polygonal meshes and texture-based materials.

HOW IT WAS DEVELOPED?

LoDCalculator has been developed using the Python Blender API. The analysis procedure is based on extracting data on the geometric and radiometric fidelity of the 3D model. This data is processed and separated using thresholds to yield 9 possible scores, from 1 to 5 with half-point intervals.

  • GEOMETRIC FIDELITY

Geometric fidelity refers to the LoD of the 3D model based on its geometry. Data for analyzing this feature is extracted from factors such as face angles or the number of polygons per mesh in the 3D model.

  • RADIOMETRIC FIDELITY

    Radiometric fidelity refers to the LoD of the 3D model based on its materials and textures. Data for analyzing this feature is extracted from factors such as the UV space occupied by faces, texture resolution, or the number of textures per material.

  • OUTPUT

    Finally, based on these values, the final LoD score is calculated. This score ranges from 1 to 5, with a half-point separation between each range. A higher score indicates a higher LoD.

USER MANUAL

  • OVERVIEW

LoDCalculator is a Blender add-on designed to analyze the level of detail (LoD) of 3D models. It evaluates geometric and radiometric fidelity, providing scores and raw data that help assess the quality of your models. Blender version 2.8 or higher is required to install LoDCalculator. You can download the latest version of Blender from the following link: https://www.blender.org/download/

  • INSTALLATION
  1. Download the LoDCalculator.py file from the repository: https://github.com/DigiUBU/LoDCalculator
  2. Open Blender and navigate to the Preferences menu.
  3. Go to the Add-ons section.
  4. Click on Install from local disk and select the downloaded .py file.
  5. The add-on is now installed and a new section called LoDCalculator will appear in the Scene Properties panel.
  • USAGE
  1. Select a 3D Model: Choose the model you want to analyze in the Blender viewport.
  2. Analyze the Model: Click the Calculate Result button in the LoDCalculator panel.
  3. Review Results: The results will display the LoD score and analysis data. If there are issues (e.g., no model selected, non-mesh object, or model without textures), an error notification will appear, and the analysis will receive the lowest possible score
  • SCORING SYSTEM
    • LoD Score: Ranges from 1 to 5, with half-point divisions, evaluating the overall model quality.
    • Partial Scores:
      • Geometric Fidelity: Ranges from 1 to 3, assessing the geometric detail of the model.
      • Radiometric Fidelity: Ranges from 1 to 3, evaluating textures and materials.
  • ANALYSIS DATA

When an analysis is executed, you can view:

    • Raw Data: Including the last interquartile range and average angles of the model’s faces.
    • Model Statistics: Number of faces and meshes, average faces per mesh, number of textures and materials, average resolution of textures, and percentage of tiled faces.
  • RELATIVE DATA COMPARISON

LoDCalculator can compare models of different scales, whether they consist of a single mesh or multiple complex meshes.

  • UNINSTALLATION

To uninstall LoDCalculator:

    • Go back to Blender’s Preferences.
    • Navigate to the Add-ons section.
    • Click on Uninstall for LoDCalculator.
  • CONTRIBUTING

If you would like to contribute to LoDCalculator, feel free to fork the GitHub repository and submit a pull request.

PAPERS

Soon.

FUNDING

This work was supported by the Ministry of Science and Innovation of Spain (MCIN/AEI/10.13039/501100011033) and by the European Union NextGenerationEU/PRTR through REMAR Project (CPP2022-009724).

Project details
PROJECT TITLE:

LoDCalculator

FIELD:

Tools

LAST VERSION RELEASE:

October, 2024

DOWNLOAD LINK:

Download here

Copyright © 2024 XRAI Lab