Generating Parametric BRDFs from Natural Language Descriptions

TL;DR

This paper presents a machine learning model that generates parametric BRDFs from natural language descriptions, enabling real-time, editable material appearances in 3D environments, which advances artistic and practical 3D content creation.

Contribution

We introduce a novel approach to map textual material descriptions to parametric BRDFs, trained with semi-supervised and unsupervised methods, integrated into NVIDIA's Omniverse platform.

Findings

Successfully generates BRDF parameters from text prompts

Enables real-time material editing in 3D environments

Supports rendering with arbitrary lighting and viewing conditions

Abstract

Artistic authoring of 3D environments is a laborious enterprise that also requires skilled content creators. There have been impressive improvements in using machine learning to address different aspects of generating 3D content, such as generating meshes, arranging geometry, synthesizing textures, etc. In this paper we develop a model to generate Bidirectional Reflectance Distribution Functions (BRDFs) from descriptive textual prompts. BRDFs are four dimensional probability distributions that characterize the interaction of light with surface materials. They are either represented parametrically, or by tabulating the probability density associated with every pair of incident and outgoing angles. The former lends itself to artistic editing while the latter is used when measuring the appearance of real materials. Numerous works have focused on hypothesizing BRDF models from images of materials. We learn a mapping from textual descriptions of materials to parametric BRDFs. Our model is first trained using a semi-supervised approach before being tuned via an unsupervised scheme. Although our model is general, in this paper we specifically generate parameters for MDL materials, conditioned on natural language descriptions, within NVIDIA's Omniverse platform. This enables use cases such as real-time text prompts to change materials of objects in 3D environments such as "dull plastic" or "shiny iron". Since the output of our model is a parametric BRDF, rather than an image of the material, it may be used to render materials using any shape under arbitrarily specified viewing and lighting conditions.