Interval Score Matching: Enhancing Fidelity in Text-to-3D Models with LucidDreamer
Tags: machinelearning, datascience, computervision, ai
Published: 2024-06-17 14:33:22

_Author: [Harpreet Sahota](https://www.linkedin.com/in/harpreetsahota204/) (Hacker in Residence at [Voxel51](https://voxel51.com/))_

## A CVPR Paper Review and Cliff’s Notes

Traditional 3D modelling is time-consuming and requires specialized skills, creating a barrier to widespread use in various industries.

Recent advancements in text-to-3D generation have shown promise yet often fail to produce models with fine details and realism. Addressing these challenges, the latest research introduces novel methodologies to bridge this gap. [This paper introduces LucidDreamer, a new system that can create detailed and realistic 3D models from text descriptions](https://arxiv.org/abs/2311.11284).

Imagine you could type “a red sports car” into a system and, within minutes, receive a highly detailed 3D model that captures the intricate curves, reflective surfaces, and precise proportions of a real sports car.

## No time to read the blog? You can hear me talk about the paper:

{% embed https://www.youtube.com/watch?v=NJQXgoARLCY %}

LucidDreamer, with its Interval Score Matching (ISM) technique, achieves this level of high-fidelity text-to-3D generation. By addressing the limitations of previous methods like Score Distillation Sampling (SDS), LucidDreamer produces 3D models with unparalleled detail and realism, making it a groundbreaking tool for applications ranging from virtual reality to digital content creation.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/el6gfx39p3jge67psbui.gif)
_<center>[LucidDreamer](https://github.com/EnVision-Research/LucidDreamer?tab=readme-ov-file)</center>_

## The Problem

Creating 3D models is usually a time-consuming task that requires expertise.

Several advancements have recently allowed us to generate 3D models from text descriptions, for example:

### Magic3D

A text-to-3D content creation tool developed by NVIDIA that generates high-quality 3D mesh models from textual descriptions. It utilizes image conditioning techniques and a prompt-based editing approach to provide users with novel ways to control 3D synthesis.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/6if6lkb7m0k6pbc8wyzy.gif)
_<center>[NVIDIA Magic3D](https://research.nvidia.com/labs/dir/magic3d/)</center>_
### Fantasia3D

A text-to-3D content creation that disentangles geometry and appearance modelling, enabling the generation of photorealistic 3D assets from text prompts. It uses a hybrid scene representation and encodes surface normals extracted from the representation as input to an image diffusion model for geometry learning.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/b4sjfqkpypyif1k7mjyp.gif)
_<center>[Fantasia3D](https://fantasia3d.github.io/)</center>_
### ProlificDreamer

A text-to-3D generation method that uses variational score distillation to generate high-fidelity and diverse 3D content from text prompts. It improves upon the existing score distillation sampling (SDS) method by modelling the 3D parameter as a random variable instead of a constant, addressing issues like over-saturation, over-smoothing, and low diversity in generated 3D models.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/r820gvyhv4kpb6w2f7eq.gif)
_<center>[ProlificDreamer](https://ml.cs.tsinghua.edu.cn/prolificdreamer/)</center>_
### Still, these methods often produce models that are not very detailed or realistic.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/l35zqgzot2p4x8a5dobb.png)

One popular method for this is called Score Distillation Sampling (SDS), but it has some issues:

- The models it creates can look “smooth” and lack detail.
- The updates it makes to improve the 3D model are often inconsistent.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/vuij3d462h7487fphsvf.png)

To solve these problems, the authors propose a new approach called **Interval Score Matching (ISM).**

**Let’s break down how this works:**

1. **Score Distillation Sampling (SDS):** First, it’s essential to understand that SDS uses a pre-trained model that can convert text to images. It tries to use this model to guide the creation of a 3D model. However, the way it updates the 3D model tends to average out details, making the final result look smooth and not very detailed.

2. **ISM Improvements:**

- **DDIM Inversion:** This is a fancy way of saying that ISM uses a method to create a consistent path for updating the 3D model, reducing randomness and improving detail.
- **Interval-Based Matching:** Instead of making big jumps in updating the 3D model, ISM makes smaller, more controlled updates. This helps maintain the details and avoid errors.

## Why It’s Better
With these improvements, **LucidDreamer** can create 3D models that are much more detailed and realistic compared to older methods. It also does this more efficiently, requiring less time and computing power.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/aos8s54gg04qih1ouhb5.png)

## Key Contributions

- **Detailed Analysis: **The authors examined why SDS wasn’t working well and identified its fundamental problems.
- **New Method (ISM):** They introduced ISM, which significantly improves the quality of 3D models.
- **Advanced Techniques:** By combining ISM with **3D Gaussian Splatting**, they enhanced the 3D model quality by reducing the training time.

## Results
The new method (LucidDreamer using ISM) was tested and shown to produce better and more detailed 3D models compared to other state-of-the-art methods like **Magic3D, Fantasia3D,** and **ProlificDreamer.**

Plus, it does this with less training, making it more efficient.

## Real-World Applications

This technology can be used in various fields, including:

- **Animation and Gaming:** Creating detailed characters and environments.

- **Virtual and Augmented Reality:** Building realistic 3D assets for VR and AR experiences.

- **Retail and Online Shopping:** Generating 3D models of products based on descriptions.

## Final Thoughts
The paper introduces significant improvements in generating 3D models from text, making the process faster and producing better-quality results. This makes it easier for people without 3D modelling skills to create high-quality 3D content.

## Learn More
The authors mentioned they will make their code available online, meaning others can use and build upon it. This is great for the research community and developers interested in this technology.

- [GitHub](https://github.com/EnVision-Research/LucidDreamer)

**If you’re going to be at CVPR this year, be sure to come and say “Hi!”**

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/qm0f7mmdyne1o533h4jc.png)