Computer Graphics Stack Exchange
Computer Graphics Stack Exchange

Questions tagged [real-time]

For questions about computations subject to real-time constraints. The minimum framerate for a real-time illusion is usually considered to be around 24 frames per second. See also [interactive] for less strict constraints and [offline] for computations which will take significantly longer.

Use this tag for questions about computations subject to real-time constraints. The minimum framerate for a real-time illusion is usually considered to be around 24 frames per second, at which the human will perceive a sequence of similar frames as fluid motion.

For more information, see Wikipedia.

See also for less strict constraints and for computations which will take significantly longer.

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Physically based shading - ambient/indirect lighting

I implemented a physically based path tracer after studying PBRT by M. Pharr and G. Humphreys. Now I'm trying to apply physically based rendering to real time graphics using OpenGL ES (in an iPhone application). I want to start using Oren-Nayar and…
Fabrizio Duroni
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How does state of the art real time hair rendering work?

It is common knowledge that hair simulation and rendering is particularly challenging and in fact rare are the examples in games that propose believable hairs. It is pretty easy to imagine how hard it is to actually simulate the high amount of…
cifz
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Projected grid water horizon detail

I'm trying to implement an ocean scene with C++ and DirectX11. Currently I have a projected grid, Gerstner waves and a basic shading. My problem is that when I aim my camera horizontally, so I can see the water horizon, in the distance, the…
Gábor Szalóki
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Is doing multiple Gaussian blurs the same as doing one larger blur?

To make Gaussian blurring a 2d image faster, I know that you can do one axis and then the other. I'm wondering though, if I did two Gaussian blurs of size $N$, would that be the same mathematically as doing one Gaussian blur of size $2N$?
Alan Wolfe
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What is "Object Space Lighting"?

Looking at Star Swarm, a demo for the Nitrous engine, I found this little line: "Nitrous uses Object Space Lighting, the same techniques used in film, including real-time film-quality motion blur." I tried looking around for anything on "object…
Ethan Shulman
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Why do multiple Gaussian Blurs?

Applying multiple Gaussian blurs can result in an effect that is equivalent to a stronger Gaussian blur. For instance this question says that: Is doing multiple Gaussian blurs the same as doing one larger blur? Wikipedia also says it, but says that…
Alan Wolfe
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Is there a way to achieve the look of a distant flock or shoal without full simulation?

Although simulation models like Boids give good results for bird flocks or fish shoals on a small scale, simulating every single member in real time becomes unrealistic for huge numbers. Is there a way I can model a flock in the distance where only…
trichoplax is on Codidact now
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How to create a patterned object with variable pattern density in real-time?

Assume there is some value p, calculated per-frame, that varies continuously over the surface of an object. The value of p determines the density of some pattern on the surface. For example, in a case with only two possible densities if p < 0.3 it…
Ryan
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Does PBR incur a performance penalty by design?

I am wondering if the various PBR models used in modern game engines for real time are heavier in terms of computation, that more classic approaches to rendering. Worded differently, is PBR just a different way to organize one's rendering pipeline,…
teh internets is made of catz
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How can I create a bounding volume hierarchy for constantly moving objects?

I'd like to be able to render a large population of small independently moving objects in real time. They may move in a swarm-like manner, but their relative positions will not be coherent - their position may change arbitrarily within a swarm and…
trichoplax is on Codidact now
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How to improve on bilateral upsampling in real time scenarios

It is a well known "standard" to use bilateral upscaling when it comes to comes to combine a low resolution target and an higher res one. I have personally noticed that using the basic algorithm (with weights based on depth differences between high…
cifz
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How is motion blur implemented in modern realtime renderers?

When realtime renderers (such as 3d games) have motion blur, how is it usually implemented? I think I've heard something about needing to have motion vectors for each pixel but I'm not sure about that and not sure how it would be used.
Alan Wolfe
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How to implement a realtime 2D light renderer with fog/colored light on the GPU?

Since long ago I wanted to implement a 2D lightning algorithm based on an idea I saw on YouTube. The video is realtime, but it runs on the CPU and the resolution is pretty low. I'm curious if anyone has an idea how to do this on the GPU. The…
sydd
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Real-time translucency effect

While rendering my scene with OpenGL, I sometimes add an overlay which contains information, settings and a few draggable items. Currently, the overlay has a slightly transparent background to make text easily readable while still allowing the scene…
Nero
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Confused about prefiltering environment maps (Manson 16)

I'm working my way through this paper about GGX-filtering environment maps: http://www.ppsloan.org/publications/ggx_filtering.pdf I find myself stuck on the basics. In particular, I am confused by two statements in section 1.1, Related Work: Most…
user3412
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