Computer Graphics Stack Exchange
Computer Graphics Stack Exchange

Questions tagged [particles]

18 questions
8
votes
2 answers

Overlaying graphics on particle simulation

How can I overlay graphics on particle simulations? For instance if I am representing a liquid or gas with tons of little points how can I make those points look like a liquid or gas? Take Nvidia Flex for instance, they simulate liquids and gases…
Andrew Wilson
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7
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1 answer

Please help me understand what happens as an image is faded to black in order to time-step particle fading

I have a game that has simple particles (basically dots) moving around the screen leaving a trail. My ultimate goal is to be able to change the opacity of the solid black fading texture each drawing call in a way so that I can keep the length of a…
J.Doe
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6
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1 answer

Fading particles and transition

I'm trying to render a particle simulation. I want each particle to leave a trace. To achieve this I'm using a framebuffer and two textures. On each frame the algorithm goes like this: Render to a framebuffer previously rendered screen texture with…
Anvaka
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6
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2 answers

Are there tricks for getting proper sort ordering on particle systems?

If you have a bunch of particles to render, using different shaders and/or render states, that have some level of transparency, the naive solution of sorting all particles by depth can be extremely inefficient since it is likely to turn a few large…
Alan Wolfe
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5
votes
2 answers

Pixel dispersion (dissolving) algorithms

This YouTube video of a flip-dot display (physical b/w pixels) shows the reverse of an effect that might be called dissolve or dispersion, i.e. a text emerges from noise by pixels moving in to form letters. Here's a short cropped clip showing just…
handle
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2
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1 answer

Represent shape as particles

Input: Triangles which make up an arbitrary shape. Each triangle is represented by 3 3D points. Output: A set of particles which fills up the inside of the object (see image). I have read the description made by GPU-Gems, and tried to implement the…
coder1337
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2
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0 answers

Vertex positions from particle position

I have a question about Nvidia Flex or any particle based simulation in general: The particles are created by sampling the mesh, which can result in fewer particles than there are vertices in the mesh. After computing the new particle positions, how…
Jojo
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2
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0 answers

How to model braids?

Many hair simulations render their hair as lines (usually splines). Since hair is a really thin object. if the hair is braided, rather than having thin infinitesimally small cylinders, you have something much thicker and with more volume per…
Makogan
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2
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0 answers

Cloud rendering and transparency order

I am working on a graphics engine designed to be used in flight simulators. It therefore has to feature an advanced weather rendering system with clouds you can fly through. For this, I implemented a particle system that renders a few hundred…
Vylsain
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2
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1 answer

Possible methods to deal with artifacts when drawing billboards to a cubemap

When drawing billboards to a cubemap, the billboard texture was incorrectly aligned on the boundaries of the cubemap between different sides. My guess is that the false projection of the billboard texture shape using the perspective cameras when…
user4613
1
vote
1 answer

Performance of particle implementation

I am about to implement the renderer for a simple particle system. Every particle has to be updated every frame (position, rotation, scale) and so I was wondering which way is usually faster: Calculate translation, rotation, scale and update the…
clamp
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1
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1 answer

Spring damping in Energy Function

Supposing a behavior function $C(x_1, \ldots, x_n)$, then we have a scalar potential energy function $E = \frac{k_s}{2}C\cdot C$ where $k_S$ is stiffness constant. Hence, the force is as follows $f_i = -\frac{\partial E}{\partial x_i} =…
shashack
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How to extract surface of smoothed particle hydrodynamics smoothly?

I'm working on a fluid simulation project where two spheres are simulated using smoothed particle hydrodynamics (SPH). I have generated two sets of particles inside and on the surface of a sphere. You can see the result in this picture: scatter plot…
Hassan
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1
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How khronos flame swing effect is done?

This demo: https://www.khronos.org/registry/webgl/sdk/demos/google/particles/ Contains multiple effects that can be done with WebGL. I've been able to recreate some of them, but for example I don't understand (even after looking at the code) how the…
hhaamm
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1
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1 answer

Stripping unnecessary data from C++ data structures before sending to GPU

I've recently been working on a particle system in my renderer and I've encountered a situation where my particle class on the C++ side has data I need to maintain my particle on that end, but that I don't need in my shader (velocity, acceleration,…
JHall
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