Questions tagged [performance]
The performance tag has no usage guidance.
55
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56 views
Optimizing compute shader with thread group shared memory
I'm currently learning compute shaders and I'm trying to write an optimized Game Of Life. I have a first version working that uses a Shader Storage Buffer Object. I dispatch a thread per cell I want ...
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0answers
37 views
GLSL asymmetric performance for point cloud
I'm currently using OpenTK (OpenGL binding for C#) to draw a lot of points (~17 million) - that very rarely change - in a cube (256 x 256 x 256) with different float "transparency weights".
...
5
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1answer
196 views
Performance of Compute Shaders vs. Fragment Shaders for Deferred Rendering
I have written a deferred renderer that can use either a fragment shader or a compute shader to execute the shading pass. Unfortunately, the compute shader implementation runs slower. I'm trying to ...
4
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1answer
82 views
Best practice for managing many shaders and merging multiple shaders into one?
I have managed to greatly minimize draw calls on my recent project, but as I'm adding more shaders, I see that I have to switch more times and that is causing a lot of draw calls. What is the best ...
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24 views
How are 2D graphics rendered in HTML canvas
I was making some circles in the HTML Canvas element and the circles were so smooth. In a sense that you cant see any vertices.
I normally work in unity and I you make a shape in 3d you most of the ...
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0answers
34 views
Optimizing texture fetches with higher mip levels
Let's say I have some shader program in DirectX or OpenGL rendering a full screen quad. And in a pixel/fragment shader I sample some huge textures at random texture coordinates. That is one same ...
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1answer
106 views
Tessellation Speed in terms of interpolated points per second
For a research project, I have written a Tessellation Shader to interpolate solution points of a 3-Dimensional mathematical equation. Therefore I don't use any techniques for displacement, I merely ...
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0answers
81 views
Software Rendering Display Latency
I've been doing some reading as to how to reduce input delay on modern computing devices. A lot of my understanding from this comes from the VR research paper by Carmack explaining the numerous ...
3
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1answer
173 views
Compute shader textures compared 2D float4 arrays
I am wondering is there a difference in performance between using floating point textures as my 2D float4 array vs just passing in 2D float4 arrays?
2D float arrays eliminate the need to do texture ...
4
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2answers
218 views
Should you measure mesh complexity in triangles or vertices?
I have seen people using either vertices or triangles as a quick heuristic to estimate mesh memory usage and mesh rendering time.
I always thought vertices were better, because the number of vertices ...
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1answer
77 views
Are MMORPGs, specifically WoW, limited by their latency in terms of FPS?
It sounds crazy, but I've been doing a lot of reading on exactly why WoW performs very poorly, even on a 1080Ti / 8700k OC'd and overall, a high-end machine.
Overclocking the CPU yielded great ...
6
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1answer
1k views
Why are tessellation shaders disliked?
I often hear that tessellation shaders aren't great for performance reasons. Something along the lines that if you try to use a tessellation shader, you'll find that the data you get out isn't ...
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338 views
Is a smaller local-size/threadgroup-size better for compute shader performance?
A compute shader defines the number of threads it requires to be executed.
This number can be called "local size" or "threadgroup size" according to the API, and be factored into 3 separate dimensions ...
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0answers
213 views
Using GPU instead of CPU in Scala
I wrote a program that displays points expressed in 3D in a 2D canvas, using perspective projection. The aim is to display a cube. Each face of the cube is drawn by linearly interpolating the points ...
4
votes
1answer
1k views
How does MSAA performance scale?
I'm finding myself increasingly interested in rendering techniques utilizing multisampling for anti-aliasing (obviously), out-of-order transparency, volumes etc.
Searching the web for performance ...
9
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2answers
533 views
The most performant way to organize vertex data on modern GPUs
Say I have a model made up of vertices, each with position, normal, tangent, and ...
4
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3answers
166 views
Dealing with wasted space when using SIMD on CPU for vector maths
I've been getting interested in SIMD programming on CPU using SSE recently, but I'm a complete noob on the subject. I found this article describing how to make an efficient float3 type using the ...
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3answers
114 views
How can an OpenGL visualization run for weeks?
For an art project, I need to make an OpenGL visualization run for at least 4 weeks. Is this possible? I can pretty much choose the rest of the hardware and software.
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0answers
318 views
In Metal, what performance advantages are there, if any, to using vertex descriptors and the [[stage_in]] qualifier?
Metal seems to provide two very different ways to access vertex data in your vertex shader. You can:
Create an MTLVertexDescriptor object, which describes vertex ...
4
votes
1answer
249 views
Tasks of a professional graphics programmer?
Currently I'm 16 and in high school and I love graphics programming and I'm seriously considering it as a career path. I was wondering what a day as a graphics programmer looks like for offline ...
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0answers
151 views
Can I voxelize 3D set of points without reconstructing surface first?
I have huge point cloud data I want to render them at interactive frame frate. Process I know is
1.point cloud data
2.triangulate it using delnauy or other triangulation algo
3.surface ...
5
votes
1answer
483 views
Performance impact during texture layer loading
Recently I have been having a rather confusing performance drop with loading in layers of a 2D texture array, but only in one case from what I can tell, leaving me to speculate on why it is happening ...
3
votes
1answer
435 views
GPU not reaching 100% usage when frame rate is dropping
I am making an iOS game using Unity. I am testing some shaders that I have made for the game, and in some cases the device will run at under 30 FPS but not have 100% device utilization.
Sometimes a ...
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2answers
494 views
Challenges of Offline Rendering
What are some of the challenges of Offline Rendering? I know one problem that is faced is performance and rendering times, are there any more issues?
Path Traced photos seem to have reached the ...
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1answer
426 views
Can I use QueryPerformanceCounter to measure single draw or compute call performance?
I know I can use QueryPerformanceCounter for measure time for whole single frame. But can I when it comes to OpenGL draw or compute call?
I always assumed that, as ...
4
votes
1answer
714 views
Register pressure in Compute Shader
I'm in the process of writing a Ray Tracer using DirectCompute / HLSL. First, eye rays are generated (one per pixel). Then, rays are traced, shaded and reflected in a loop. Also, shadow rays for each ...
6
votes
2answers
408 views
How can I improve the performance of my custom Global Illumination approach?
I want to experiment with some new stuff about modern rendering techniques and in that way I'm trying to implement a custom GI (somewhere between pathtracing and instant radiosity).
My scene is a bit ...
6
votes
1answer
360 views
Optimizing performance on hardware
I'm working on a webgl audio visualizer that uses particles, and I want to optimize rendering based on the user's hardware. I'd like to offer a "low quality" and "high quality" setting so that it ...
4
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1answer
338 views
How to get unique nearest neighbour?
There's already something called K-nearest neighbour algorithm with gives nearest neighbour to points. But what I want is unique neighbour which is not shared by any other neighbour.
I've implemented ...
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0answers
502 views
Billboards or impostors when objects' instances are re-scaled [closed]
Billboarding/impostors mean, roughly, representing complex 3D objects in 2D or with simple quadrilaterals, for the sake of LOD systems.
Consider the case of rendering a very numerous asteroid field ...
10
votes
1answer
231 views
Why did AMD's putting an SSD on a GPU board reduce latency so much?
AMD have recently been in the news with an interesting Radeon Pro board with a couple of M2 SSDs on it.
As some of the more detailed stories (here or here, for example) note, the benefits may ...
7
votes
1answer
534 views
Estimating the area of a triangle-circle intersection
I am trying to implement Ray Tracing with Cones (Amanatides 1984). Instead of rays, cones are shot into the scene and intersected with geometry. Since multiple triangles can occupy the cone's aperture,...
4
votes
2answers
6k views
What are the differences between GPU instancing and standard instancing?
I have been reading a lot of debate on a new feature that will be available in the new version of the game engine Unity 5.4 - called GPU instancing. I understand the importance of instancing in ...
8
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1answer
962 views
How does everyone count “Rays per Second”?
Recently I'm developing a Monte-Carlo path tracer. To measure my tracer's performance, I decided to implement a simple mechanism to count how many rays can it trace in a second. Then here comes the ...
3
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1answer
378 views
Data structure and algorithm for clipping triangulation with leaf nodes of an octree
I have an application in which I am using an octree to store a volume mesh of axis-aligned bounding boxes (AABBs).
Given a water-tight manifold triangle mesh, I need to:
find if an AABB is ...
7
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2answers
234 views
What methods/technologies to reduce required performance for virtual reality are there?
I'm interested in virtual reality, but according to some sources, less than 1% of computers in use today have the necessary performance to run modern VR games, granted many of them are not intended ...
16
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3answers
5k views
Why do we have graphics frameworks like OpenGL and DirectX, when games could just draw pixels directly?
Games and other graphically intensive applications use frameworks like OpenGL and DirectX. Also they require features like pixel shader and DX12.
But why would we need all these frameworks and GPU ...
11
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1answer
4k views
Loop performance in a shader
I am wondering what's the best way to integrate a dynamic loop function in a shader?
First, it seems that dynamic arrays are not possible. So, is it better to create a maximum size array and only ...
8
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1answer
346 views
Do modern GPUs contain barrel shifters?
I'm aware that most modern GPUs, although designed for floating point, are more or less equivalent in integer performance these days, with a few caveats like the lack of a fused multiply add. I'm not ...
2
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0answers
252 views
Projecting light shapes
I am wondering how professional light visualizer software (like Capture Argo - WYSIWYG - Realizzer - LightConverse) project the lights on the objects (like stage, floor, people), even projecting the ...
16
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3answers
5k views
Difference between rendering in OpenGL and 3D animation software
With OpenGL and such I can render some pretty amazing looking things in "real time" 60 FPS. However, if I try to make a video of that same scene in let's say Maya, or 3ds Max it would take MUCH MUCH ...
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2answers
433 views
With modern fillrates and deferred rendering, is occlussion culling still relevant?
For example, while it's the current top-of-the-line GPU, the GTX 980 has a staggering 72.1 gigapixels/second fillrate, which with back-to-front rendering and/or Z buffer checks, seems almost ...
2
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1answer
127 views
Is there some book about how to design a 3D math lib? [closed]
3D math covers vector algebra and matrix algebra, which are easily calculated on paper, but not so easy when coding them effectively. I only leant some basic algorithms on matrix in my Data Structure ...
8
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2answers
209 views
When is it better to upload partial model matrices to the vertex shader?
As of now, when rendering my scene and while iterating through the scene graph, for each node its model matrix is calculated from the parent's model matrix and the scene node's pose. This is quite ...
8
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1answer
623 views
Shader uniform performance
I'd like to know if there's any performance impact based on how I struct my shader uniforms. For instance, is passing 4 floats worse than passing a single vec4?
14
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1answer
805 views
Is a constant condition more costly than switching shaders?
In general, branching in shaders is not a good idea. But now I have a shader with a condition that is constant with respect to the entire draw call. So the branch that is executed is always the same ...
5
votes
2answers
3k views
How to reduce the number of draw calls when rendering one object multiple times?
Especially when rendering particle effects, the same object needs to be rendered several times with slightly modified properties. But these changes are often limited to properties like pose or ...
11
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1answer
7k views
Why is accessing textures much slower when calculating the texture coordinate in the fragment shader?
When using textures in GLSL, it is best to calculate the final texture coordinates in the vertex shader and hand them over to the fragment shader using varyings. ...
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1answer
2k views
Why is this conditional in my fragment shader so slow?
I have set up some FPS-measuring code in WebGL (based on this SO answer) and have discovered some oddities with the performance of my fragment shader. The code just renders a single quad (or rather ...
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1answer
2k views
What is the performance tradeoff between forward and deferred rendering?
Forward rendering is the process of computing a radiance value for a surface fragment directly from input geometry and lighting information. Deferred rendering splits that process into two steps: ...
