Questions tagged [opengl-es2]

OpenGL ES 2.0 emphasizes a programmable 3D graphics pipeline (comparing to fixed-function pipeline of OpenGL ES 1.1).

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20
votes
5answers
13k 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 ...
17
votes
2answers
1k views

OpenGL: Where shoud I place shaders?

I'm trying to learn OpenGL ES 2.0 and I'm wondering what is the most common practice to "manage" shaders. I'm asking this question because in the examples I've found (like the one included in the API ...
16
votes
2answers
33k views

GLSL Shader - Change Hue/Saturation/Brightness

I'm trying to change the hue of an image using a GLSL fragment shader. I want to achieve something similar to Photoshop's Hue/Saturation Adjustment layer. In the following image you can see what I've ...
13
votes
4answers
11k 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 ...
12
votes
1answer
14k views

Should unbind buffers?

I'm making some tests with OpenGL ES 2 and got some questions, my current program is like that: ...
11
votes
4answers
6k views

2D collision detection

Let's assume I'm using this character. (source: iconbug.com) How would you implement collision detection for it? Using a bounding box doesn't seem to be a good approximation, because the bird's shape ...
11
votes
3answers
11k 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, ...
11
votes
1answer
2k views

How can I reliably implement GPU skinning in Android?

I'm trying to get character skinning working on Android. The idea is quite vanilla: I have my skinning matrices, and along with each vertex, I send up to four matrix indices and four corresponding ...
10
votes
1answer
4k views

Sprite sheet textures picking up edges of adjacent texture

I have a custom sprite routine (openGL 2.0) which uses a simple sprite sheet (my textures are arranged horizontally next to each other). So, for example, here is a test sprite sheet with 2 simple ...
10
votes
2answers
16k views

Taking advantage of multithreading between game loop and openGL

Talking in context of a game based on openGL renderer : Let's assume there are two threads : Updates the game logic and physics etc. for the in game objects Makes openGL draw calls for each game ...
10
votes
3answers
18k views

Confusion over GLViewport

I'm hoping someone can help me understand the GLViewport and what happens when we resize it This will illustrate my confusion.... So, here I have a quad stuck in the middle of the screen. If I have ...
10
votes
1answer
5k views

OpenGL ES create stencil effect using texture

Environment This is the environment I am working in: OpenGL ES 2.0 iPhone Simulator & iPhone 4 iMac 27" using NVIDIA GeForce GTX 680MX 2048 MB Hope that helps. The Problem Been searching ...
9
votes
4answers
6k views

Impact of variable-length loops on GPU shaders

Its popular to render procedural content inside the GPU e.g. in the demoscene (drawing a single quad to fill the screen and letting the GPU compute the pixels). Ray marching is popular: This means ...
9
votes
3answers
8k views

How do I send multiple matrices to a vertex shader?

I'm practising animations using bones/skinning. I am trying to send the shader one matrix per vertex. I can think of these two approaches. Method 1 I have one uniform handle for each bone matrix like ...
9
votes
1answer
5k views

Optimizing performance of a heavy fragment shader

I need help optimizing the following set of shaders: Vertex: ...
8
votes
2answers
1k views

What's the best way to draw lots of trees

I'm writing an app which renders a random island planted with trees. The trees are currently two quads, criss-crossed and drawn with textures. I plan to have more complex meshes that form different ...
8
votes
3answers
3k views

What is Khronos EGL?

I see that modern OpenGL related code uses EGL, i can't get good resources for this so i ask here: what exactly is EGL ? if a platform supports OpenGL ES 2.0+ or OpenGL 3.0+ i can presume that will ...
8
votes
2answers
983 views

How to avoid subpixel values in a resolution independent 2D game with orthographic projection?

I'm trying to do resolution independent rendering of moving sprites in a 2D game. My plan is work in a fixed coordinate system in my world (for example 960x540) and use orthographic projection to ...
8
votes
1answer
2k views

GL ES: Fragment shader optimization

Summary: I get FPS slowdown as soon as I try to tint the sprites (i.e: multiply texture with color in the fragment shader) Details: Hardware: iPod touch 4 I am drawing 700 sprites on the screen ...
8
votes
2answers
3k 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 ...
7
votes
3answers
1k views

What's the best practice for a progress bar in OpenGL ES 2.0?

My attempt: I make a texture (could be a single colour or otherwise), and then stretch that texture from a minimum 0 up to a maximum ...
7
votes
2answers
765 views

Draws fine in full OpenGL; not drawing anything in Chrome NaCL

I'm appealing to people's psychic debugging skills: I have an OpenGL app that uses shaders and attributes in uploaded VBOs exclusively. It runs fine on the desktop (Linux with integrated Intel card). ...
7
votes
1answer
387 views

Optimal batching for 2D objects with transparency

I have a collection of 2d objects with transparency. Each object has a depth value to determine draw order and a material. I'm trying to batch them in an optimal way to minimize draw calls. Assume ...
7
votes
2answers
2k 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 ...
6
votes
2answers
11k views

How can I use an unsigned int as a GLSL attribute for OpenGL ES 2

I'm having trouble finding conclusive information on this, but it seems like I can't pass integer attributes to GLSL for OpenGL ES or that if I do they'll be converted to float. I need a value between ...
6
votes
2answers
3k views

OpenGL 3.0+ framebuffer to texture/images

I need a way to capture what is rendered on screen, i have read about glReadPixels but it looks really slow. Can you suggest a more efficient or just an alternative way for just copying what is ...
6
votes
1answer
574 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 ...
6
votes
1answer
1k views

Sprite with alpha Blending in 3D world

I'm working on a game in a 3D world with elements 2D only (Like Don't starve game) for Android and IOS. Currently, I've managed "Sprite" without alpha blending, I've just put a condition in the pixel ...
6
votes
1answer
4k views

Optional samplers in shaders

I have a scene. Sometimes I draw untextured, coloured, semi-transparent triangles, sometimes I texture them, and I draw a lot of both in a fairly interleaved manner. In a fixed function pipeline the ...
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 ...
6
votes
1answer
13k views

OpenGL ES 2 on Android: native window

According to OGLES specification, we have the following definition: ...
6
votes
1answer
1k views

Android game loop's effect on cpu/battery usage - unexpected results

I will try to keep this question as concise and as readable as I can. I recently came across an odd problem with my Android game that I'm developing. It's an openGL ES 2.0 game and initially I was ...
6
votes
1answer
2k views

How can I organize render and transformation data in a scalable fashion?

I am writing for OpenGL 2.0 and in the future porting to OpenGL ES 2.0. I only use VBOs and shaders (no immediate mode, no vertex arrays). I already have working solutions, they just... feel wrong. ...
6
votes
1answer
383 views

How to prevent clipping when moving through a tunnel?

I'm developing for Android using OpenGL ES 2.0. It's going to be a game where you have to fly through a tunnel without hitting the walls. However, the tunnel wall gets clipped as the player ...
6
votes
1answer
840 views

FBO rendering different result between Galaxy S2 and S3

I'm working on a pong game and have recently set up FBO rendering so that I can apply some post-processing shaders. This proceeds as so: Bind texture A to framebuffer Draw balls Bind texture B to ...
6
votes
1answer
2k views

exporting bind and keyframe bone poses from blender to use in OpenGL

EDIT: I decided to reformulate the question in much simpler terms to see if someone can give me a hand with this. Basically, I'm exporting meshes, skeletons and actions from blender into an engine ...
6
votes
1answer
177 views

OpenGL self-test in a mobile game

I've made an Android game that uses no/custom game engine. It renders using OpenGL ES 2.0 and optionally uses some extensions for optimization or extra effects. Over the time I have dealt with various ...
6
votes
2answers
788 views

Implementing realistic sun reflection on a sea

I'm drawing a 3d rendered island which has a day / night cycle and a sun that rises and sets over water. The sea is rendered with a fragment shader derived from this Blinn-Phong tutorial. http://...
5
votes
3answers
6k views

How can I make a shader effect that looks like a lightly shaded pencil drawing?

I want to make a shader effect using OpenGL ES 2.0 that looks like this image: I'm not sure if this image was painted or is the result of some filter, but I want to create a shader that produces ...
5
votes
5answers
5k views

Should we always prefer OpenGL ES version 2 over version 1.x

OpengGL ES version 2 goes a long way into changing the development paradigm that was established with OpenGL ES 1.x. You have shaders which you can chain together to apply varios effects/transforms to ...
5
votes
1answer
747 views

Calculated normals for mesh not working

I am trying to implement a 3D mesh viewer with C++ and OpenGL ES 2. I am currently struggling with the calculation of the normals for the vertices, or at least I think that is where the problem lies......
5
votes
4answers
2k views

How to visually “connect” skybox edges with terrain model

I'm working on a simple airplane game where I use skybox cube rendered using disabled depth test. Very close to the bottom side of the skybox is my terrain model. What bothers me is that the terrain ...
5
votes
2answers
2k views

OpenGL sprites and point size limitation

I'm developing a simple particle system that should be able to perform on mobile devices (iOS, Andorid). My plan was to use GL_POINT_SPRITE/GL_PROGRAM_POINT_SIZE method because of it's efficiency (...
5
votes
2answers
2k views

OpenGL ES 2.0: 2D game rendering, no performance gain with glDraw call batching

I just did a small benchmark. To my surprise batching sprites into a single draw call doesn't give any significant performance boost. Following are my results: Hardware: iPod touch 4 Extra info: ...
5
votes
1answer
1k views

OpenGL ES 2.0 obscured texture is visible

Hi, I am using LibGDX and OpenGL 2.0 to create a game. So far I have created two meshes. The front mesh is the one with the brown circle texture and another mesh on the top with a green to white ...
5
votes
1answer
2k views

OpenGL ES 2.0 texture distortion on large geometry

OpenGL ES 2.0 has serious precision issues with texture sampling - I've seen topics with a similar problem, but I haven't seen a real solution to this "distorted OpenGL ES 2.0 texture" problem yet. ...
5
votes
1answer
4k views

OpenGL ES 2.0. Sprite Sheet Animation

I've found a bunch of tutorials on how to make this work on Open GL 1 & 1.1 but I can't find it for 2.0. I would work it out by loading the texture and use a matrix on the vertex shader to move ...
5
votes
1answer
353 views

GetData() error creating framebuffer [closed]

I'm currently porting a game written in C# with XNA library to Android with Monogame. I have a Texture2D and i'm trying to get an array of ...
4
votes
4answers
930 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 ...
4
votes
1answer
3k views

Fragment shader seems to floor() imprecisely

I'm trying to interpolate coordinates in my fragment shader. Unfortunately if close to the upper edge the interpolated value of fVertexInteger seems to be rounded ...

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