3 research outputs found
Real-time Realistic Rain Rendering
Artistic outdoor filming and rendering need to choose specific weather conditions in order to
properly trigger the audience reaction; for instance, rain, one of the most common conditions, is
usually employed to transmit a sense of unrest. Synthetic methods to recreate weather are an
important avenue to simplify and cheapen filming, but simulations are a challenging problem due
to the variety of different phenomena that need to be computed. Rain alone involves raindrops,
splashes on the ground, fog, clouds, lightnings, etc. We propose a new rain rendering algorithm
that uses and extends present state of the art approaches in this field. The scope of our method is
to achieve real-time renders of rain streaks and splashes on the ground, while considering complex
illumination effects and allowing an artistic direction for the drops placement.
Our algorithm takes as input an artist-defined rain distribution and density, and then creates
particles in the scene following these indications. No restrictions are imposed on the dimensions
of the rain area, thus direct rendering approaches could rapidly overwhelm current computational
capabilities with huge particle amounts. To solve this situation, we propose techniques that, in
rendering time, adaptively sample the particles generated in order to only select the ones in the
regions that really need to be simulated and rendered.
Particle simulation is executed entirely in the graphics hardware. The algorithm proceeds by
placing the particles in their updated coordinates. It then checks whether a particle is falling as a
rain streak, it has reached the ground and it is a splash or, finally, if it should be discarded because
it has entered a solid object of the scene. Different rendering techniques are used for each case.
Complex illumination parameters are computed for rain streaks to select textures matching them.
These textures are generated in a preprocess step and realistically simulate light when interacting
with the optical properties of the water drops
Real-time Realistic Rain Rendering
Artistic outdoor filming and rendering need to choose specific weather conditions in order to
properly trigger the audience reaction; for instance, rain, one of the most common conditions, is
usually employed to transmit a sense of unrest. Synthetic methods to recreate weather are an
important avenue to simplify and cheapen filming, but simulations are a challenging problem due
to the variety of different phenomena that need to be computed. Rain alone involves raindrops,
splashes on the ground, fog, clouds, lightnings, etc. We propose a new rain rendering algorithm
that uses and extends present state of the art approaches in this field. The scope of our method is
to achieve real-time renders of rain streaks and splashes on the ground, while considering complex
illumination effects and allowing an artistic direction for the drops placement.
Our algorithm takes as input an artist-defined rain distribution and density, and then creates
particles in the scene following these indications. No restrictions are imposed on the dimensions
of the rain area, thus direct rendering approaches could rapidly overwhelm current computational
capabilities with huge particle amounts. To solve this situation, we propose techniques that, in
rendering time, adaptively sample the particles generated in order to only select the ones in the
regions that really need to be simulated and rendered.
Particle simulation is executed entirely in the graphics hardware. The algorithm proceeds by
placing the particles in their updated coordinates. It then checks whether a particle is falling as a
rain streak, it has reached the ground and it is a splash or, finally, if it should be discarded because
it has entered a solid object of the scene. Different rendering techniques are used for each case.
Complex illumination parameters are computed for rain streaks to select textures matching them.
These textures are generated in a preprocess step and realistically simulate light when interacting
with the optical properties of the water drops