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

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5answers
3k views

2D collision detection

Let's assume I'm using this character. 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 is nowhere near a ...
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2answers
1k 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 ...
0
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1answer
4k views

OpenGL ES 2.0 gluUnProject

I've spent more time than I should trying to get my ray picking program working. I'm pretty convinced my math is solid with respect to line plane intersection, but I believe the problem lies with the ...
15
votes
2answers
605 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 ...
8
votes
1answer
232 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 ...
3
votes
2answers
3k views

Android: Loading bitmaps without premultiplied alpha (OpenGL ES 2.0)

Is this possible? To load textures in non-premultiplied format (Straight alpha?)? My game has 1 or 2 images which have semi-transparent pixels and I need to be able to fade them in and out but this ...
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 ...
5
votes
1answer
834 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 ...
5
votes
4answers
2k 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 ...
3
votes
3answers
2k 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 ...
3
votes
1answer
818 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 ...
2
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1answer
904 views

Separate renderng thread in Android (OpenGL ES 2.0)

I'm used to mainly working with the Canvas SurfaceView API on Android and have recently been learning openGL ES 2.0 With canvas I know that surfaceView gives you the ability to start a new thread to ...
1
vote
1answer
206 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 ...
1
vote
2answers
165 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
205 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 ...
1
vote
1answer
391 views

Centering GLViewport position within physical screen

I'm developing my app on one device and want it to display at the same ratio on all other devices. Currently what I have is 'image 1' in my image below - the game fits perfectly onto my development ...
1
vote
0answers
372 views

Converting motionevent.getx and motionevent.gety to pixel or Object coordinates in the view

I am trying to draw buttons using OpenGL I have added a Gesture Listener for the GLSurface View now i have motionevent when ever the user touches. My question is how can i convert motionevent.getx and ...
0
votes
1answer
139 views

Problem rendering simple OBJ model using assimp in android app

I am trying to load an OBJ model (http://pastebin.com/usGFkf4e) into an Android app using Assimp 3.1.1 Assimp model loaded like this : bool CGameObject::LoadModelFromFile(AAssetManager *amgr, ...
0
votes
1answer
533 views

Get back or delete an existing OpenGL object, then change it and draw at new. How?

With OpenGL i'm drawing for example a circle. Can i take this drawn circle back out of the window and change something and then draw it back on the window? Or can i /have to delete it and then draw ...
0
votes
3answers
227 views

Understanding how to go from a scene to what's actually rendered to screen in OpenGL?

I want something that explains step by step how, after setting up a simple scene I can go from that 'world' space, to what's finally rendered on my screen (ie, actually implement something). I need ...