Real‐time Realistic Rendering and Lighting of Forests

Abstract

Special issue: Proceedings of Eurographics 2011International audienceRealistic real-time rendering and lighting of forests is an important aspect for simulators and video games. This is a difficult problem, due to the massive amount of geometry: aerial forest views display millions of trees on a wide range of distances, from the camera to the horizon. Light interactions, whose effects are visible at all scales, are also a problem: sun and sky dome contributions, shadows between trees, inside trees, on the ground, and view-light masking correlations. In this paper we present a method to render very large forest scenes in realtime, with realistic lighting at all scales, and without popping nor aliasing. Our method is based on two new forest representations, z-fields and shader-maps, with a seamless transition between them. Our first model builds on light fields and height fields to represent and render the nearest trees individually, accounting for all lighting effects. Our second model is a location, view and light dependent shader mapped on the terrain, accounting for the cumulated subpixel effects. Qualitative comparisons with photos show that our method produces realistic results

Procedural generation and interactive web visualization of natural environments

“…Both families of techniques lack the ability to correctly translate ecological input data, like coverage or patchiness data of plant species, to a plant distribution with high-density and variety. Moreover, most techniques or examples of interactive 3D visualization of high density natural environments focus on desktop applications [8,9], which are unlikely to be used in the context of ecological management or policy. It is not possible to use these techniques directly in a web environment, because browser-based solutions do not have the same rendering capabilities as desktop-based solutions.…”

“…There are several desktop-based solutions that are able to render large amounts of plants [8,9]. Often, these techniques focus on rendering one or two plant species with a high density in the environment, but they achieve interactive frame rates with it.…”

“…Bruneton [8] developed a technique, which is able to render a realistic forest representation in real-time with realistic lighting at all scales. They use a z-field representation to render the nearest trees individually and a shader map representation to render far-away trees.…”

“…Therefore, neighboring plants are grouped together and a single check is made for the whole group. These groups are generated by dividing the plant distribution and storing it in a quadtree structure [22] [8]. The whole distribution is divided in four equal quads and each of these quads is again divided in four quads.…”

“…Billboards Efficient and effective methods for generating billboards use geometry shaders so that only a single vertex has to be sent to GPU, which is then transformed in the geometry shader to various planes [8]. However, in WebGL geometry shaders are not available.…”