Clement Shimizu

Automotive Spray Paint Simulation

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. The simulation provides two different output modes: a non-photorealistic display that gives a visual representation of how much paint has landed on the surface, and a photorealistic simulation of how the paint would actually look on the object once it has dried. Useful feedback values such as overspray are given. Experiments were performed to validate the system.

VR spray painting for training and design

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. The simulation provides two different output modes: a non-photorealistic display that gives a visual representation of how much paint has landed on the surface, and a photorealistic simulation of how the paint would actually look on the object once it dried. Useful feedback values such as overspray are given. Experiments were performed to validate the system.

Computer aided color appearance design using environment map based lighting

A BRDF approximation is developed that is suitable for interactive color appearance design in direct lighting provided by environment maps. The BRDFs are approximated as a linear combination of cosine lobes with a fixed set of specular exponents. A nonlinear optimization routine is used to fit the cosine lobes to BRDFs appropriate for a specific color appearance design application: automotive paint. Modification and rendering of the BRDF is made possible by linearly combining prefiltered environment maps for each cosine lobe in real time.

Computational automotive color appearance

A computer graphic system has been developed that permits the interactive design of new automotive finishes. The software makes use of a reflection model for car paint that is based on industry standards for measuring the appearance characteristics of the paint. These measurements include gloss for the clearcoat and three aspecular measurements for the metallic basecoat. The program interface provides a means for altering the reflectance properties of the paint and for visualizing the effect of those changes on the color appearance of the car. The desired aspecular measurements for the new paint can be input to a paint formulation system so that the paint can be manufactured. A test of the system shows good correspondence between the designed and the fabricated paint.

OmniMap: Projective Perspective Mapping API for Non-planar Immersive Display Surfaces

Typical video projection systems display rectangular images on flat screens. Optical and perspective correction techniques must be employed to produce undistorted output on non-planar display surfaces. A two-pass algorithm, called projective perspective mapping, is a solution well suited for use with commodity graphics hardware. This algorithm is implemented in the OmniMap API providing an extensible, reusable C++ interface for porting 3D engines to wide field-of-view, non-planar displays. This API is shown to be easily integrated into a wide variety of 3D applications.