Subset of the OpenGL 3D graphics API designed for embedded devices such as mobile phones.

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1answer
178 views

Artifacts when draw particles with some alpha

I want to draw in my game some particles. But when I draw one particle above another particle, alpha channel from this above "clear" previous drawed particle. I set in OpenGL blend in this way: ...
0
votes
2answers
568 views

Help with Meshes, and Shading

In a game I'm making in LibGdx, I wish to incorporate a ripple effect. I'm confused as to how I get access to the individual pixels on the screen, or any way to influence them (apart from what I can ...
11
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6answers
12k views

OpenGL ES 2.0: Repository of Quality Shaders

Could I kindly ask, to suggest me a repository of high quality OpenGL (OpenGL ES 2.0) vertex and fragment shaders, please? I am looking for pixel based ligting shaders (such as phong) and simmilar. ...
1
vote
2answers
754 views

What is the best way to store meshes or 3d models in a class

I am wondering, how I should store my mesh into memory after loading it from whatever file. I have Questions floating in my head: Should a mesh could have sub meshes or does the 3d model just store ...
0
votes
1answer
153 views

Writing a basic shader for large input files

I started writing a shader for my iOS app and instead of starting from scratch i used this tutorial here: http://www.raywenderlich.com/3664/opengl-es-2-0-for-iphone-tutorial I wrote an import ...
13
votes
1answer
2k views

Should I distribute shaders in a compiled form or in plain text?

Having an application that uses shaders that have been wrote in GLSL, what is the best strategy for the distribution in the real world and for the desktop and mobile? I'm aiming to distribute this in ...
0
votes
3answers
6k views

2D Rendering with OpenGL ES 2.0 on Android (matrices not working)

So I'm trying to render two moving quads, each at different locations. My shaders are as simple as possible (vertices are only transformed by the modelview-projection matrix, there's only one color). ...
1
vote
1answer
174 views

if a desktop machine supports OpenGL 3.0+ I can assume that it supports OpenGL ES 2.0 too?

This isn't clear for me, if i use the drivers from the GPU manufacturer and they support OpenGL 3.0 and/or above, i can always make an OpenGL ES 2.0 application work?
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votes
1answer
1k views

Reducing Memory Use on OpenGL ES

I'm using an opengl es based framework to create my game.I have an out of memory problem on some devices.I have 15 textures with a size 1024x1024(totally 10 mb).On memory they covers a lot of ...
2
votes
3answers
1k views

glGetFloatv – should it be avoided? Can it be replaced?

Platform is OpenGL ES 1.x. I am using glGetFloatv() to get MODELVIEW matrix. This allows me to compute points, where I need to draw a shadow effect. This is very handy, as I can forget about ...
0
votes
1answer
130 views

android opengl-es spritesheet display number

Whats the best way to display numbers on android with opengl using a spritesheet? I like to display the number "294" using the spritesheet: http://i.stack.imgur.com/wv5Zh.png
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vote
2answers
822 views

Android OpenGL textures sometimes corrupted

Just trying to get some sprites (textured squares) to draw from a texture atlas and 50% of the time after the application is first launched/ reorientated/ brought from sleep these various graphical ...
0
votes
2answers
443 views

Can I dynamicaly modify 3D objects?

I am new to OpenGL, I am able to render a model object (a human model) that is using .obj and .mtl file in iOS. Now I want to make a modification to the loaded model. For example, I want to change ...
3
votes
1answer
3k views

Sea water shader using only fragment processor

I have a game that runs on mobile devices (OpenGL ES 2.0) and for which I would like to create some sea water using the shaders. Now, the plane on which the sea water texture will be has only 4 ...
1
vote
2answers
398 views

Lights system with shaders in OpenGL?

In more than just 1 occasion, i read about 2 ways of doing a light's system in OpenGL: normal way? i don't know how to call this one with the shaders ( GLSL ) The problem is i don't get the ...
2
votes
1answer
111 views

Touch point on the near plane

I have a matrix created with either orthoM or frustumM GL function, where the near plane is logically the surface of the tablet. I would like to translate touch locations to their location on the near ...
6
votes
1answer
2k views

OpenGL ES 2.0 Best Practices / Architecture Guide

I've recently started working with OpenGL (ES 2.0) on the Android. While there is lots of documentation about the basics, I can't seem to find much about the overall architecture of OpenGL. In ...
1
vote
1answer
1k views

Shader authoring/editing tools for GLSL ES

Since Render Monkey has been discontinued (perhaps due to the complexity of today's shading languages), there are few successors that can match its functionality. Is there any useful tool for material ...
4
votes
3answers
4k views

OpenGL ES and Screen Coordinates

Is there anyway I can make OpenGL ES 2.0 to accept coordinates (for Vextex for example) in int meaning the pixels instead of the default float system? Also how can I set the point (0,0) to be at the ...
1
vote
1answer
620 views

How to obtain contrail visual effect?

I have objects moving in OpenGL ES1 application. I want some of them to leave behind contrail – like if they would emit some radiation or something. EDIT: the kind of contrail is: light contrail – ...
4
votes
1answer
755 views

Creating a highlight halo around a selected object

I'm looking to create a halo highlight around the selected objects in my game screen. The main platform is android, but I am writing an iOS version as well, updating it whenever I successfully add the ...
1
vote
1answer
498 views

Why is my mesh generation algorithm not working properly?

I am trying to generate a grid in OpenGL ES, using known methods for triangle strips and stitching as shown in: this post and this post The code below, generates the vertices for a 4x4 grid with a ...
1
vote
1answer
2k views

2D Quads : Translation with OpenGL ES 2.0 on Android [closed]

I have a simple 2D engine that renders 2D textured quads, and right now I can scale the quad or rotate it, but when I try to translate it I have a strange distortion (the quad is squashed in the half ...
-1
votes
1answer
3k views

How to display bitmap using Texture api in android opengl

I want to display a bitmap image at screen using texture api in android opengl. Some code which I have used in our code as below. public void onSurfaceChanged(GL10 gl, int width, int height) { ...
1
vote
0answers
250 views

Getting contour without the background [closed]

I have a texture and vertex which are needed to create a set of closed polygons. For this purpose I use these functions: Code for create texture: CCSprite* spr = ...
1
vote
0answers
201 views

Remove “dots” noise (like from dot-matrix printer)

I have 2D array of floats. Using the floats, I generate image by doing proportional selection of color from between COLOR_MIN, COLOR_MAX – for maximal float value at given (x,y), I choose COLOR_MAX ...
4
votes
2answers
437 views

Geometry vs sprites

I'm developing an android game, where the enemies are geometrical shapes. Performance is a main goal for me so I was wondering if defining shapes directly in OpenGL would be more efficient than using ...
2
votes
3answers
3k views

How do I render .dae models?

I'm building a game for iOS. I'm quite new to OpenGL but what I want is to take a 3D model I have made in Google SketchUp and use it in my 3d game. The problem is I don't know how to proceed. I have ...
3
votes
2answers
5k views

Creating an OpenGL FPS camera: I have the position and orientation vectors, now what?

I have been struggling to create a first person camera in OpenGL ES 2.0 without using gluLookAt(). I grab the camera's orientation vectors (the way it's looking) from the current modelview matrix, and ...
7
votes
2answers
3k views

OpenGL ES 2.0: Mixing 2D with 3D

Is it possible to mix 2D and 3D graphics in a single OpenGL ES 2.0 game, please? I have plenty of 2D graphics in my game. The 2D graphics is represented by two triangular polygons (making up a ...
2
votes
2answers
3k views

How to use OpenGL's glUseProgram?

While in the rendering loop, is it OK to call glUseProgram? Does it have a big overhead? I'm planing to use a program for each different material in the scene. I'm a real beginner with OpenGL and I'm ...
5
votes
4answers
4k views

Geometry instancing in OpenGL ES 2.0

I am planning to do geometry instancing in OpenGL ES 2.0 Basically I plan to render the same geometry(a chair) maybe 1000 times in my scene. What is the best way to do this in OpenGL ES 2.0? I am ...
0
votes
0answers
347 views

Camera rotation flicker in OpenGL ES 2.0 [on hold]

I implemented an orbit camera in my own OpenGL ES 2.0 application. I was getting extensive amount of flicker while rotating the camera using the mouse. When I added the line eglSwapInterval( ..., ...
1
vote
1answer
153 views

Drawing texture does not work anymore with a small amount of triangles

When i draw lines, the vertices are well connected. But when i draw the texture inside the triangles, it only works with i<4 in the for loop, otherwise with i<5 for example, there is a ...
1
vote
1answer
322 views

Adjust sprite bounds of the visible part of texture

Is there any way to adjust the boundaries of the visible part of the sprite? To make it easier to understand: I have a texture, such as shown at figure 1. Then I break it into pieces and fill the ...
10
votes
3answers
4k views

How can I bend an object in OpenGL?

Is there a way one could bend an object, like a cylinder or a plane using OpenGL? I'm an OpenGL beginner (I'm using OpenGL ES 2.0, if that matters, although I suspect, math matters most in this case, ...
1
vote
1answer
2k views

Texture displays on Android emulator but not on device

I have written a simple UI which takes an image (256x256) and maps it to a rectangle. This works perfectly on the emulator however on the phone the texture does not show, I see only a white ...
1
vote
2answers
3k views

How to determine counter-clockwise vertex winding

I've been causing myself some confusion lately with regards to vertex winding in a mesh class that i'm writing. Currently, the mesh contains the appropriate structures for: vertices (vector3) ...
1
vote
1answer
723 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
381 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 ...
5
votes
3answers
14k views

glTranslate, how exactly does it work?

I have some trouble understanding how does glTranslate work. At first I thought it would just simply add values to axis to do the transformation. However then I have created two objects that would ...
1
vote
1answer
909 views

Where to start creating a 2d rain simulation with OpenGL ES 1.1?

I'm using opengl 1.1 and i'm creating a 2d side scrolling game.How can i render a 2d rain simulation?What is logic for that?
0
votes
2answers
1k views

Problem with drawing textures in OpenGL ES

I'm developing a 2D game for Android and i'm using the framework which has been told in the book which named Beginning Android Games by Mario Zechner.So my framework is well designed and using OpenGL ...
0
votes
1answer
383 views

Triangles in a C++ STL Vector as an Objective-C member sometimes draws incorrectly in OpenGL ES

The polygons draw correctly 80% of the time. When it fails, a vertex is dislocated. The polygon is consistently drawn with the wrong vertex. I checked that the vector is correct during initialization, ...
1
vote
1answer
367 views

From simple physics with a ball, to a more complicated shape

Hello fellow game devs and stack overflowers... I recently made a transition from OpenGL ES 1.1 to 2.0 (on Android via NDK) and things are going well so far. I'm working on doing a dice rolling ...
1
vote
1answer
1k views

Handling different screen densities in Android Devices?

Well, i know there are plenty of different-sized screens in devices that run Android. The SDK I code with deploys to all major desktop platforms and android. I am aware i must have special cares to ...
1
vote
3answers
5k views

Open GL ES 2.0 with Android

I was wondering if someone could recommended a book that covers both android game developement and OpenGL ES 2.0. I have found some books with OpenGL 1.0, but I have heard that the syntax for OpenGL ...
0
votes
1answer
939 views

Determining and culling non-visible vertices

Ahoy! After posting my previous question on tile maps, i've been tinkering with an implementation i'm rather pleased with so far but would like to gather some more information about submitting ...
3
votes
1answer
611 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 ...
0
votes
4answers
1k views

Should I use a VBO if the vertex data changes from time to time?

If I have a very large number of vertices, but they're static for about 70% - 80% of their life time, should I use a VBO for them? If so, what usage should I specify? This doesn't sound like a case ...