Metaballs. Perlin Noise. Difference of Gaussian. TechFest 2008: Real Time Rendering of Smoke Animation. One would think that Real Time Rendering of Smoke Animation in this technological era would be a cake walk.
Well, it isn't and here's why: Rendering of smoke presents a challenging problem in computer graphics because of its complicated effects on light propagation. Within a smoke volume, light undergoes absorption and scattering interactions that vary from point to point because of the spatial non-uniformity of smoke. In static participating media, the number and the complexity of scattering interactions lead to a substantial expense in computation. For a dynamic medium such as smoke, the intricate volumetric structure of which changes with time, the computational costs can be prohibitive.
Computer Science Fog Machine Improves Computer Graphics [Jacobs. San Diego, CA, April 15, 2008 -- UC San Diego computer scientists have created a fog and smoke machine for computer graphics that cuts the computational cost of making realistic smoky and foggy 3-D images, such as beams of light from a lighthouse piercing thick fog.
By cutting the computing cost for creating highly realistic imagery from scratch, the UCSD computer scientists are helping to pull cutting edge graphics techniques out of research labs and into movies and eventually video games and beyond. The findings are being presented this week at Europe’s premier computer graphics conference, Eurographics 2008 in Crete, Greece on April 17. This new work is part of a shift in the computer graphics, film, animation and video game industries toward greater realism through the use of “ray tracing algorithms.” At the heart of the new UCSD advance are computationally slimmed “photon mapping” algorithms, which are a subset of the ray tracing algorithms.
Computerized Fog Costs. Water Simulation. The color of water is influenced by a number of factors, especially by and light conditions, so it's radically different on a sunny day vs. an overcast day. Realtime Scalable Real-Time Animation of Rivers , Uses a pixel shader on overlapping tiles, with a 'flow' texture providing the speed, direction and size of the waves so they can vary over a scene. Provides a good expanation on the topic, pictures, movies and even source code built on OSG 2.8.3 Realtime Interactive Animations of Liquid Surfaces with Lattice-Boltzmann Engines , Cristian García Bauza et al The approach is intended to produce scenes of ponds whose surface reacts to perturbations introduced by the user or controlled by the computer, like drizzle or the stirring of a finger. the page Phymo - Water Module has a public implementation with demos.
High Contrast Shaders. Filed Under Programming High Contrast Shaders posted by sysrpl on Tuesday October 13, 2009 1:13 PM The problem: hen drawing inside polygons using a GPU shader, if your shader outputs areas containing high contrast sloping lines, those lines will be aliased.
Multisampling does nothing to fix the aliasing, as multisampling only serves to smooth the edges of geometry and not their interior fills. Fig 1. What is needed: A methodology to perform anti-aliasing inside your shader. My solution: Determine the arc width θ of your smoothing distance, for example the arc across a pixel by diving your field of view by the number of vertical pixels in your scene. Convert θ to foreshorten ratio ω using the equation ω = 1 / sin(θ).
Account for the distance and slope of the surface by multipling ω, z depth, and then dividing by dot product of the eye vector to surface normal vectors to form Ω i.e. Steep Parallax Mapping. I3D 2005 Poster; Brown Technical Report April 1, 2005 Abstract.
We propose Steep Parallax Mapping, a new bump mapping scheme that can produce parallax, self-occlusion, and self-shadowing for arbitrary bump maps. It uses existing data formats, is a straightforward extension to the state-of-the-art parallax mapping, and can shade every pixel at 1024 x 768 at 30fps with 4x FSAA, making it practical for games. Related Work Blinn and Newell's (1976) texture mapping first mapped images over surfaces to create the illusion of detail without adding geometry. Blinn's bump maps (1978), today implemented using Cook's normal map format (1984), allow flat surfaces to have not only the color but the appropriate shading of the perceived detail geometry. Texture and normal mapping are standard effects in modern games.