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.

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Best practice for per-vertex updates for mass-spring simulation?

I am new to graphics and physics simulation. I am trying to perform a mass-spring simulation on CPU on individual vertices inside a mesh, and wondering how to best handle this. If working with a rigid ...
5 votes
1 answer
1k views

How does directional Gaussian blurring work?

In image editing software, you often have the ability to do a directional blur where you can choose and angle and a magnitude of a blur. How does this actually work in practice with Gaussian blurring? ...
1 vote
0 answers
130 views

Time Interval Ray Tracing performance

I found a very nice paper regarding Time Interval Ray Tracing for Motion Blur published in 2017. That was before RTX GPUs were on the market. I have a few questions about an optimal implementation and ...
7 votes
2 answers
5k views

How does vsync affect fps exactly when not at full vsync fps?

I know that if you turn of vsync, it synchronizes rendering with the vertical redraw cycle to prevent tearing, and that doing so caps your rendering rate (FPS) at the monitor refresh rate, which is ...
0 votes
0 answers
72 views

Is it possible that a superior, undiscovered 3D rendering method exists?

As far as I know, the only options we have for true 3D rendering are polygonal rendering, ray-marching and raytracing/casting. Why is that? Surely there must be other ways? Is there some paper ...
0 votes
1 answer
143 views

Fastest Simulation Of Mass Spring Systems

I'd like to simulate a 4-dimensional cloth in the web browser, since browsers don't offer great ressources for numerical computation, I'd like to know which algorithm uses the least amount of ...
1 vote
1 answer
45 views

What can be reduce in peripheral circle and increase in foveated cirle?

Foveated rendering, is definitely one of the newest fields of real-time graphics rendering. The main goal of foveated rendering is reducing rendering cost to increase frame-rate without perception ...
9 votes
3 answers
1k views

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 ...
0 votes
2 answers
95 views

What exactly is it about reality that is so difficult to recreate in a 3D simulation?

I have to admit that, while watching footage of the enhanced 2020 version of the 2018 game Forza Horizon 4, when they are driving fast, I have to sometimes remind myself that I am watching a video ...
3 votes
1 answer
201 views

How can I make a graphics demo without a frame buffer?

I am programming a microcontroller - a tiny 8 bit computer that has about 100Mhz - 300Mhz CPU clock speed and 64K application RAM (actually ROM), but only a tiny amount of RAM (6K) - nowhere near ...
0 votes
1 answer
1k views

How to display an in-memory framebuffer

I'm planning to write a small software rendering engine (before anyone asks, it's kind of a learning/scientific experiment for me). Before writing any code, I'm already stuck at the very first step: ...
2 votes
0 answers
48 views

Accelerating dose calculation for a radiation therapy planning system

During radiation therapy, appropriate radiation is fired from various positions around the patient. Radiation therapy planning determines the values of the radiation at various positions. This ...
1 vote
0 answers
52 views

What modern C++ Unit Testing Framework do you use for highly parallel image, 3D and higher dimensional matrix processing workloads? [closed]

Most of the existing open-source libraries such as OpenCV, Tensorflow, and Pytorch use Google Test. I would like to know about strong alternative testing frameworks that thrive under a similar ...
3 votes
2 answers
1k views

Phong: Real-time rendering of Metal and Plastic Materials

Using a shader that works like Phong, what would be the difference between painted Metal and plastic? I seem to remember reading in books years ago, that I no longer have access to, the following: ...
5 votes
2 answers
5k views

What are the current open problems in Computer Graphics?

I did a quick investigation about the topic but there doesn't seem a decent resource to find related problems without digging into latest CG papers (unlike CS problems you can easily find a Wikipedia ...
12 votes
1 answer
5k views

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 ...
0 votes
0 answers
64 views

What is it that really prevents photo-realistic, real-time, digital 3D simulations?

Ever since I was a small child, seeing the amazing 3D visuals that developed in the 1980s and 1990s, I was certain that photo-realism was "just around the corner". In the year 2020, I certainly ...
2 votes
1 answer
293 views

light probe (for global illumination) placement techniques?

I'm learning light probes used for dynamic global illumination. I have a question regarding the placement of light probes, as based on most of the pictures I have seen, they seem to be placed ...
1 vote
0 answers
20 views

How to handle object drawables?

Currently the graphics API I am using is Vulkan, but I am trying to find a general enough way to represent the following. In graphics, drawing can be generalized as: Get vertex buffers and send them ...
1 vote
0 answers
713 views

How to display image from CUDA / What API to port my project to for real-time raytracing?

I started a raytracing project using the python numba library which provides a just-in-time compiler for CUDA kernels. When the scene is rendered my result is a 1920 x 1080 x 3 RGB array in GPU memory....
2 votes
1 answer
807 views

Downscaling texture via mipmap [DirectX 11]

I am implementing a post-processing effect in my DirectX 11 pet renderer. The post-processing pass is implemented by rendering a full-screen quad covered with texture containing original rendered ...
0 votes
1 answer
97 views

How to draw depth-based volume in real-time

Normally when we talk about realistic transparent volumes, we care about refraction (and total internal reflection), and we care about scattering. But there's a much simpler case of volume ...
5 votes
0 answers
286 views

Why is Forward Rendering/Shading named this way?

Forward rendering is the 'classic' approach to the rendering pipeline. Nowadays it is mostly replaced by a more flexible, deferred rendering approach. I did some research and had trouble finding ...
-1 votes
2 answers
253 views

What is a list of common, cheap, real time rendering algorithms?

I am well aware of the existence of Blinn-Phong shading, which is a great tool when you are doing, for example, modelling algorithms and wan't to focus on the model. In this case a full BRDF result, ...
1 vote
1 answer
76 views

Consistent animation speed across systems

I recently noticed that in all games, no matter what system you play on or what specs you have, your character will always move at the same speed even if there is no frame rate limit. I was wondering ...
5 votes
1 answer
1k views

Benefits of Clustered Shading vs Tiled Shading?

The Unity Engine manual page Best Practice: Setting up the Lighting Pipeline has a section "Render pipelines" with an illustration of Tile Rendering and Cluster Rendering: The section then mentions:...
3 votes
1 answer
417 views

Importance Sampling in Unreal Engine Formula Derivation (Irradiance term)

I am currently trying to understand IBL in Unreal Engine, and there are so much things that I don't understand about the formula. Unreal approximate the specular term of shading equation by doing ...
10 votes
1 answer
2k views

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 ...
1 vote
1 answer
734 views

Radiosity normal map light baking

I'm trying to implement radiosity normal maps from the old Valve paper: Half-Life® 2 / Valve Source™ Shading.pdf | valvesoftware.com I've tried generating the light maps using Vray and 3dStudio max, ...
5 votes
1 answer
160 views

Correct post-displacement normal calculation (Y-component and epsilon)

I often use a 2D Perlin noise texture to displace a grid in the vertex shader (e.g. terrain, ocean). However, every time I google the method to calculate post-displacement normals there is a slight ...
6 votes
1 answer
194 views

fix over exposure in importance sampling in screen space reflections

I am having my first encounter with the rendering of indirect reflections in the form of screen space reflections in a game engine, but i am struggling to get correct looking results. (patterns arise ...
3 votes
1 answer
849 views

Advantages of spherical harmonics over baked vertex lighting?

My question is about spherical harmonic lightning, in the context of computing the coefficients with an expensive GI algorithm and passing them to the vertex shader Another way is to just use an ...
6 votes
0 answers
236 views

How is Ambient Occlusion calculated in "Deep Screen Space"?

The paper (http://resources.mpi-inf.mpg.de/DeepScreenSpace/) just says that "The ambient occlusion contribution of a surfel to a pixel [..] as well as the influence radius [..] are computed ...
4 votes
1 answer
459 views

What is better to use for real-time computing Mesh - Plane intersection points, GPU or CPU?

I want to write plugin (library) for Unity3d (it doesn't matter which framework I will choose for this, question is ), for cutting arbitrary mesh with plane (for simplicity it will be plane for ...
2 votes
0 answers
63 views

Is this the correct interpretation of the separable SSS artistic model?

I'm trying to understand the separable subsurface scattering algorithm, but I'm a little confused on what the parameters mean from a notation and implementation standpoint, particularly for the ...
7 votes
1 answer
1k views

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 ...
7 votes
1 answer
1k views

Subsurface Scattering Without Rays?

Some games claim to use subsurface scattering but my current understanding of sss is only achieved with ray tracing. How would you sub surface scatter without ray tracing? Do some claim to use sss but ...
14 votes
4 answers
1k views

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 ...
1 vote
1 answer
643 views

What framework shoud I use to implement the RAISR upscaling algorithm on the GPU?

I recently ran across the paper RAISR: Rapid and Accurate Image Super Resolution and thought it seemed like an interesting technique for scaling up images. However, I haven't seen any implementation ...
1 vote
1 answer
1k views

Which technique is fast to generate real-time reflections?

I want to know about some technique with which i can generate nice reflections on the surface. I know one conventional technique where we invert an object and render it and blend it with the floor but ...
7 votes
2 answers
898 views

Selection of GI techniques working in real time

I'm considering topic of my thesis connected with computer graphics - I would compare some GI techniques which work completely in real time (no precomputation to lightmaps etc. and each frame ...
4 votes
0 answers
65 views

Is it possible to create a forced focus with a dual layer of images in order to Avoid eye strain with Virtual and Augmented Reality?

Would eye tracking allow for the alignment of a dual layered image (a google glass like device and a screen or projection) to provide a way to force the focus of the eyes into to a real life ...
4 votes
3 answers
583 views

Texture coordinates projection

I have some classic texture coordinates and as a normal behaviour they follow the mesh's transformations. I am trying to use the same texture coordinates behaviour but without being affected by the ...
18 votes
3 answers
9k views

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 ...
2 votes
1 answer
262 views

Real time image based lighting for arbitrary BRDFs coordinate alignment

I was trying to understand how real-time illumination happens with image-based lighting. I understood that importance of representing the Environment Map and BRDF in spherical harmonics. Because ...
4 votes
1 answer
71 views

In what order to apply lighting and translucency?

I'm making a game that is supposed to like like a early 90s 3D game, so i'm rendering in software on an 8-bit indexed bitmap, using lookup tables for translucency and lighting. Now I have to draw a ...
2 votes
2 answers
84 views

live music visualisation [closed]

Does anyone out there know of any software for developing real time visualisations and analysis of real time sound, say using a mike? I've found a few but none allow the user to build up their own ...
9 votes
2 answers
316 views

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 ...
5 votes
1 answer
235 views

Questions about Preconditioning Conjugate Gradient method in Baraff & Witkin 98?

I encountered some problems when implementing the cloth simulation algorithm from Baraff & Witkin 98's Large Steps in Cloth Simulation. Baraff & Witkin 98 Consider the cloth as a particle ...
6 votes
1 answer
646 views

Methods for grid traversal in a glsl pixel shader?

I'm working on a shadertoy "snake" game, using the new multi pass rendering abilities to save game state between frames. I'm using raytracing to render the board (an AABB), and am planning on using ...