Tagged Questions

5
votes
1answer
63 views

GLImpl.gldrawelements longer than usual

I'm developing a little game engine for the Android platform and I'm trying to improve the performance of this one. (I'm not an OpenGL expert) I can see a framerate drop sometimes, when using DDMS ...
0
votes
0answers
47 views

iOS billboard rendering performance

What is the fastest way to render semi-transparent billboards (for a particle system) on iOS? I'm currently using GLES1, but if required for performance I can switch to GLES2. Does sorting the quads ...
1
vote
1answer
84 views

Animate multiple entities

I'm trying to animate multiple(3) entities using one model(IQM format). It's working but performance is really bad because I'm calling animate function for each entity in my game loop (I think ...
0
votes
0answers
82 views

Opengl binding shaders vs binding buffers performance

Quick question for an opengl guru, I'm in the process of building a render queue and can either reduce the number of shader binding or the number of vertex buffer binding. I just want to know which ...
5
votes
1answer
509 views

VBO and gl*Pointer management practises?

I'm aware it's not a simple yes/no question and for the moment I can't tell if it can be simply answered, or is it topic for a long discussion which is not suitable for our Q&A format. I want to ...
0
votes
1answer
1k views

Triple buffering causes input lag?

Consider some time in between two vsyncs. Suppose the first display buffer is being used to display the current image, and suppose the game was really fast and computed and rendered the next image to ...
2
votes
2answers
298 views

Can frequent state changes decrease rendering performance?

Can frequent texture and shader binding decrease rendering performance? "Frequent" binding example: for object for material in object render part of object using that material "Low count" ...
1
vote
2answers
565 views

Simple OpenGL program major slow down at high resolution

I have created a small OpenGL 3.3 (Core) program using freeglut. The whole geometry is two boxes and one plane with some textures. I can move around like in an FPS and that's it. The problem is I face ...
16
votes
1answer
7k views

What is the benefit of triple buffering?

I read everything written in a previous question. From what I understand in double buffering the program must wait until the finished drawing is copied or swapped before starting the next drawing. In ...
7
votes
2answers
432 views

Does use of simple shaders improve performace/battery life?

I'm making OpenGL game for Android. Till now i've used only fixed function pipeline, but i'm rendering simple things. Fixed function pipeline includes a lot of stuff i don't need. So i'm thinking ...
6
votes
2answers
383 views

An odd performance problem rendering a simple scene (less than 14k vertices) in OpenGL using two vbos with LWJGL

Problem I have been having a strange degrading performance issue rendering a simple scene containing two "chunks" of 4x4x4 cubes each. Video of problem This is a screen capture showing my console ...
1
vote
1answer
812 views

Optimized algorithm for line-sphere intersection in GLSL

Well, hello then! I need to find intersection between line and sphere in GLSL. Right now my solution is based on Paul Bourke's page and was ported to GLSL this way: // The line passes through p1 and ...
1
vote
1answer
452 views

Multiple buffering in OpenGL on Windows

What is the most common way modern games perform triple buffering ? What does the SwapBuffers exactly do in terms of OpenGL states ? Is it possible to perform double and triple buffering ...
5
votes
1answer
229 views

Can I leverage the fact that my scene is often static to improve OpenGL (JOGL) performance?

My scene is drawn based on the location of several (often several million) vertices (kept in VBO's) and a camera. I can easily tell in my code when my scene has changed and when it hasn't. There are ...
17
votes
6answers
5k views

How can I improve rendering speeds of a Voxel/Minecraft type game?

I'm writing my own clone of Minecraft (also written in Java). It works great right now. With a viewing distance of 40 meters I can easily hit 60 FPS on my MacBook Pro 8,1. (Intel i5 + Intel HD ...
9
votes
3answers
2k views

Why does OpenGL >= 3 only allow VBOs?

I see that OpenGL versions 3 and up eliminate the use of client-side rendering. Immediate mode has been eliminated, and vertex arrays seem to be deprecated. Instead, if I understand correctly, VBOs ...
0
votes
1answer
285 views

Game (X-Plane) boot/startup time / performance

I use X-Plane for my question but it also concerns probably every other flight-simulator or simulation game in general. When developing a plugin what bothers me most is the startup-time of the ...
-3
votes
0answers
283 views

Why OpenGL provided with latest GeForce drivers is so extremely slow?

I'm writting a code in OpenGL and using two computers - an old and a new one. On the old computer (which I use for debugging/creating implementation for the old GL) I have GeForce 5500 FX. Before ...
5
votes
1answer
459 views

How to insert and remove blocks quickly in a Minecraftian world?

I currently have volume data for the world stored as an array of booleans. I then check each empty block and if it has non-empty neighbors the faces get drawn. This prevents me from sending a bunch ...
3
votes
2answers
2k views

OpenGL VBOs are slower then glDrawArrays

So, this seems odd to me. I upload a large buffer of vertices, then every frame I call glBindbuffer and then the appropriate gl*Pointer functions with offsets into the buffer, then I use glDrawArrays ...
1
vote
5answers
904 views

OpenGL Performance Questions

This subject, as with any optimisation problem, gets hit on a lot, but I just couldn't find what I (think) I want. A lot of tutorials, and even SO questions have similar tips; generally covering: ...
8
votes
4answers
6k views

How to improve batching performance

I am developing a sprite based 2D game for mobile platform(s) and I'm using OpenGL (well, actually Irrlicht) to render graphics. First I implemented sprite rendering in a simple way: every game object ...
2
votes
2answers
371 views

Make OpenGL game perform better

I have programmed an OpenGL game which just contains one F1 car and a track. It is very simple and only uses around of 10'000 - 20'000 triangles. It should run on any PC but it won't, it needs a ...
22
votes
5answers
7k views

why would you use textures that are not a power of 2?

In the early days of OpenGL and DirectX, it was required that textures were powers of two. This meant that interpolation of float values could be done very quickly using shifting and such. Since ...
3
votes
4answers
1k views

how to do partial updates in OpenGL?

It is general wisdom that you redraw the entire viewport on each frame. I would like to use partial updates; what are the various ways can do that, and what are their pros, cons and relative ...
13
votes
1answer
540 views

Is there any performance benefit to sharing shaders between programs?

OpenGL allows you to share the same shader between multiple programs. Aside from saving small amounts of memory and a shader handle, are there any GPU-side performance benefits to doing this?
8
votes
5answers
1k views

Geometric Transformations on the CPU vs GPU

I've noticed that many 3d programs normally do vector/matrix calculations as well as geometric transformations on the CPU. Has anyone found an advantage in moving these calculations into vertex ...
3
votes
2answers
579 views

Expected OpenGL performance

I'm benchmarking some simple code for drawing using OpenGL. In the following code, the number of indices being drawn is 4,644 (or 1,548 triangles per frame = @60fps 92,880 Triangles per second). ...
5
votes
5answers
753 views

What are some low-level performance tweaks for iPhone games written in c?

I'm interested in some performance tweaks for a relatively simple OpenGL ES based 2D iPhone game. What performance tweaks have you found? The performance of the game is pretty good on most devices ...