New computer graphics tools are developed for use in the automotive paint design
and paint application industries. These tools are designed to aid in every aspect of automotive
painting from initial paint design all the way to viewing a final spray paint job.
This thesis also provides new computer graphics techniques by leveraging industrial appearance
standards and measurement instruments to yield new interaction, rendering and
First, a system is introduced for the simulation of spray painting. Head mounted
display goggles are combined with a tracking system to allow users to paint a virtual
surface with a spray gun. Ray tracing is used to simulate droplets landing on the surface
of the object, allowing arbitrary shapes and spray gun patterns to be used. This system
is combined with previous research on spray gun characteristics to provide a realistic
simulation of the spray paint including the effects of viscosity, air pressure, and paint
pressure. Experiments were performed to validate the system for use as a training tool.
Next, a virtual airbrush tool is introduced. The basic particle simulation used in the
spray paint system is modified to include the finer control needed for airbrushing. Paint
mixing between colors applied to the surface is modeled using Kubelka-Munk theory.
Computerized stencils, including semi-permeable stencils, can be manually positioned by
the artist or projected onto the object’s surface. The resulting airbrush system can be used
by airbrush artists to both practice their craft as well as to decorate virtual models.
The dissertation then utilizes an industrial measurement instrument to simulate the
surface roughness in automotive paint finishes. This simulation is integrated with a design
interface to enable industry professionals to devise new paints that have detailed surface
effects. The industrial measurement device can also be used to rapidly measure and render
real world materials without the need for elaborate full BRDF acquisition tools. Finally, the surface model developed in this research can be used to study human detection of
small scale surface roughness.
Lastly, new projection systems are introduced to display the paints generated by the
previous algorithms. A desired paint is projected onto the surface of an object, making
that object appear to be painted with that material. This allows painters to evaluate how
the final painted surface will look in a very natural way. A novel projection system is also
described in which the user can hold and evaluate a flexible sample of virtual paint. This
provides a more compelling display of the paint than a standard 2D monitor can generate.
These display methods can also be used to display materials other than paint, potentially
benefiting a large range of industries.
The combination of these tools is intended to allow spray painters to design paints,
paint them onto an automobile or other object, and verify exactly what the result will
look like before ever having to manufacture the paint itself. The use of these tools could
therefore reduce wasted paint, speed up training times, and allow for precise design of
automobile appearance: all before ever manufacturing any real paint. In addition to aiding
paint industries, these tools enhance the current state of the art in computer graphics. The
airbrush tool provides a new texture creation system that existing airbrush artists can use
with little to no training; the surface roughness simulation provides enhanced rendering
of automotive paint that could be used in movies and games; and the projection display
system improves the state of the art in augmented reality systems.