7
votes
1answer
182 views

How do I reconfigure my GLES frame buffer after a rotation?

Note: In order to keep the question as simple as possible, I am actively changing the body of the question to reflect the current state of affairs, instead of adding stuff at the bottom. I am ...
0
votes
2answers
98 views

OpenGL 2.0 - How to swap buffers for color picking

I'm trying to reproduce color picking on iOS, following the technique described here: http://www.lighthouse3d.com/opengl/picking/index.php3?openglway2, with OpenGL ES 2.0. When the user touches the ...
1
vote
1answer
105 views

In 3D camera math, calculate what Z depth is pixel unity for a given FOV

I am working in iOS and OpenGL ES 2.0. Through trial and error I've figured out a frustum to where at a specific z depth pixels drawn are 1 to 1 with my source textures. So 1 pixel in my texture is ...
0
votes
1answer
115 views

Normal Map Issues

I'm experiencing a very strange result in my very simple normal map implementation on iOS 7 - OpenGL ES 2.0. I'm only using the bare parameters necessary and I'm also skipping on all the tangent and ...
1
vote
0answers
135 views

iOS OpenGLES - Multithread Game loop - Render and Update

I am trying to implementing multi-threaded game loop in iOS. (Actaully, two thread - Render and Update) This is my structure. Update Loop Has logic and at the end of loop, save update state. ...
6
votes
1answer
222 views

overlapping 3d particles not blending nicely when at the same z

I'm working on a 3d particle emitter. It's going pretty good but I'm still having a problem with triangle sorting. As you can see in the photos, there are some particles that are not blending ...
1
vote
2answers
109 views

matrix to rotate a vector to a known arbitrary axis

Let's say I have a vector V (v.x,v.y,v.z) which is normalized and points somewhere in 3d space. And that I have another vector Z of (0,0,1). Knowing only these two things I'm looking for a ...
1
vote
2answers
141 views

Adding an angle variance to a 3d vector

I am converting a particle emitter from 2d to 3d. In the 2d system the original coder used a random angle variance and added it to the angle. So it would be something like: thisAngle = emitterAngle ...
2
votes
2answers
140 views

What are the pros. and cons. of different representations a custom geometry format for a mobile based engine?

I am trying to create 3D model importer for my mobile based engine. These are what I am considering: Convert .obj file to text based structure like JSON or custom. So, basically, convert .obj ...
5
votes
1answer
119 views

portal cutoff effect

I want a 3D Mesh to come out of a flat portal. Only the part of the mesh that's coming out of the portal should be rendered, so the mesh should be cut off or sliced until it's fully outside the ...
1
vote
1answer
268 views

iOS: OpenGL ES 2.0 render texture with glScissor performance

I have drawn image with OpenGL and will redraw tile of its texture (non filled area). Which case will work faster? Set glViewport with full texture's rect, draw full texture and use glScissor ...
0
votes
2answers
190 views

OpenGL ES, orthopgraphics projection and viewport

I want to make some simple 2D game on iOS to familiarize myself with OpenGL ES. I started with Ray Wenderlich tutorial (How To Create A Simple 2D iPhone Game with OpenGL ES 2.0 and GLKit). That ...
3
votes
2answers
527 views

OpenGL ES 2.0: Enabling hi-res on iOS

I created an empty iOS project and then added a custom GLView class which is then added to AppDelegate. I have following questions: 1) How do I enable hi-res retina mode on iPhone 4? Currently I am ...
0
votes
1answer
546 views

iOS OpenGL ES 2.0 How to Billboard on Sphere and Rotate with Sphere

I have a sphere (earth) in OpenGL ES 2.0 for iOS. I also have markers that I want to place at lat/lons on the earth - but I want the markers to always face the user ( billboards ) but also move with ...
1
vote
1answer
99 views

in an ios open gl es 2 game - is it better to use a few large texture atlas or many small textures

I'm working on new game, this time moving to more 3d objects and open gl es 2. Previous (successful) game was open gl es 1 and mostly 2d. For es 2 I'm developing my own 3d engine. My 3d artist ...
-1
votes
1answer
108 views

GLES2 rendering performance for different iPad generations

I'm using C++/GLES2 for iPad only (no iPhone). The only device I own is an iPad2 and I do not plan to support iPad 1. Can anyone help me understand realistic goals/limits on iPad 2/3/4 in terms of ...
3
votes
4answers
562 views

Benefits of upgrading from OpenGL ES 1.1 to 2.0 on iOS

I have an animated 3D iPhone game that I first wrote using OpenGL ES 1.1 in late 2009. After many updates to the rest of the game, the OpenGL ES 1.1 code still runs fine under iOS 6, but I'm ...
2
votes
1answer
175 views

What causes the iOS OpenGLES driver to allocate extra memory?

I'm trying to optimize the memory usage of our iOS game and I'm puzzled about when/why the iOS GLES driver allocates extra memory at runtime... When I run our game through Instruments with the OpenGL ...
0
votes
1answer
350 views

OpenGL ES 2. How do I Create a Basic Fading Streak Effect?

For the iPad app I am writing using OpenGL ES 2 I have a single quad - shaded using GLSL - that is dragged around the screen. Very basic. This works fine. But is rather boring. I want to increase ...
0
votes
1answer
493 views

OpenGLES how to make a 3D object iOS

I am a newbie in OpenGLES, so pardon me if I cannot state the question properly. Is it possible to create a 3D box with the following imports only: OpenGLES, QuartzCore, GLKit I have created a 2D ...
1
vote
1answer
611 views

OpenGL ES 2 - glSwapBuffers?

this is what i do to blit FBO onto screen in ViewController: [m_Context presentRenderbuffer:GL_RENDERBUFFER]; but i need something like glSwapBuffers, so that i can call it somewhere from the ...
0
votes
1answer
347 views

Straightforward guidelines for converting OpenGL to OpenGL ES?

Is there a straightforward list of finite steps that I need to follow to convert an OpenGL program into an OpenGL ES that's used on the iPhone and iPad? I'd be using GLKit. I've seen some similar API ...
2
votes
2answers
1k views

Can I use PBOs for textures in iOS?

As far as I can see, there is no GL_PIXEL_UNPACK_BUFFER. Also, the OpenGL ES 2.0 specification (and as far as I know, no iOS device currently supports OpenGL ES > 2.0) states that glMapBufferOES() can ...
3
votes
1answer
558 views

Can glTexImage2D() use an already existing memory block?

Can I use glTexImage2D() and / or glTexSubImage2D() (or maybe there's some other method I don't know about) with an already existing block of memory, instead of always uploading the changed pixels? I ...
1
vote
3answers
985 views

iOS - pass UIImage to shader as texture

I am trying to pass UIImage to GLSL shader. The fragment shader is: varying highp vec2 textureCoordinate; uniform sampler2D inputImageTexture; uniform sampler2D inputImageTexture2; void main() { ...
2
votes
2answers
3k views

What is the proper use of CADisplayLink, and where do I put game logic?

I have an iOS OpenGL ES 2.0 game and currently have a CADisplayLink with a :render method. In this render method I do all the game's logic updates and drawing. Is this correct? Or should my game ...
2
votes
1answer
2k views

in iOS, does CADisplayLink automatically control the app's 'timestep'?

I'm writing an iOS game that uses OpenGL ES 2.0. I have my 'OpenGLView' which contains a - (void)setupDisplayLink { CADisplayLink* displayLink = [CADisplayLink displayLinkWithTarget:self ...
6
votes
2answers
1k views

Getting the number of fragments which passed the depth test

In "modern" environments, the "NV Occlusion Query" extension provides a method to get the number of fragments which passed the depth test. However, on the iPad / iPhone using OpenGL ES, the extension ...
15
votes
3answers
6k views

Is deferred rendering/shading possible with OpenGL ES 2.0 ?

I asked this on StackOverflow, but it might make more sense here: Has anyone implemented deferred rendering/shading under OpenGL ES 2.0? It doesn't support MRTs, so with only one color buffer, it's ...