OpenGL is a graphics standard and API which targets the desktop and workstation markets. It is designed to be easy to accelerate with dedicated computer hardware, and hence most implementations give greatly improved performance over traditional software rendering. Currently, OpenGL is used for ...

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How to store sprite data in a VBO?

I'm planning on rendering many sprites in my games, but I am not sure which method of storing their data to use. I haven't tried all of them yet, but I want to see if I also have anything important ...
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23 views

How can I draw multiple lines connected via “nodes” in libgdx Scene2D?

I have two Vectors which indicate the ending points of each line. I am trying to draw similar lines to football formation lines like these. My main problem using ShapeRenderer is: ShapeRenderer ...
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1answer
119 views

Transparency sorting in 3D world with different render types

I am rendering a world, object, and models from an older game format. The world is presented in a BSP tree so I can quickly iterate through. The opaque surfaces are rendered front to back. Then ...
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1answer
2k views

Does multiple downsampling have a benefit?

So i came across this site and you can see these lines on the first and second paragraph: For a crude but easy effect, draw the bright portions of the scene (eg, light sources) into an FBO, then ...
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1answer
22 views

Translation matrix applyed to the view matrix not working (android opengl2)

I have managed to do an small app using opengl2 in android. It consists on a sphere moving over a rectangle, both with a texture. It's just a test in which I'm testing my first steps in opengl. Now ...
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29 views

How can I use ImGui to render simple text instead of using stb_truetype directly?

Since ImGui builds on top of stb_truetype for its font rendering, I thought it could be nicer to use its already built font-processing capabilities (ImGui::GetIO().Fonts), and render with those, ...
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20 views

How can I render text with modern OpenGL and stb_truetype, and why are the loaded textures black?

I've spent the past couple of days just desperately trying to get stb_truetype to render anything using the simple example provided ...
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1answer
34 views

Normals showing unexpected results

I am making a game in c++ with opengl and glm and was working on my terrain when this happend : as it appears it is renderering just the way i planned it, but my question was, how do i make it ...
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1answer
39 views

Failed to understand how to use glm::unProject (OpenGL 4.3)

Situation: I use OpenGL 4.3, FreeGLUT 3.0, and GLM library. Let say i have a simple 2D object (a ball) and it moves accordingly to the simple equations: x = x_0 + v_0 * t * cosf(alpha); y = y_0 + ...
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1answer
34 views

Shader only rendering 1/4th of the screen

I've asked the same question on SO here and they suggested I should ask here instead. I'm currently trying to create a gaussian blur shader, and while I've successfully created the blur effect my ...
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2answers
2k views

Identity matrix, What does it really do?

I understand that multiplying by the identity matrix is like multiplying by 1. Why would you multiply a matrix that will only contain the same result? Also, I'm experimenting with some OpenGL code ...
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29 views

Opentk hdr rendering with framebuffer white screen problem

I am trying to do hdr rendering with two shader programs: one simply draws a hdr texture on a fullscreen quad and the other one does tonemapping. I am trying either linear tonemapping colorOut = ...
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18 views

How could I add XBox 360 Controller handling support to my game?

The title says it all. I'm making a 3D Open World game with OpenGL and LWJGL in Java, and I really need to move in several angles to fully feel inside the game. The problem is that I couldn't find any ...
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26 views

virtual keyboard using opengl , glut, visual basic [on hold]

I have coded a simple virtual keyboard using open gl which just have functionality of basic operation of clicking on key(rectangle box) which displays text.. I want to add some functionality of SHIFT ...
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2answers
92 views

Build a vbo once every second

I have a VBO storing some data in my game. The thing is, the data can change at a rate of about a second. The data is not fixed size, meaning that some objects will sometimes be visible, sometimes ...
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2answers
51 views

Opentk Textured Full Screen Quad

I want to display a texture on a full screen quad. What I get is a completely green quad and after a week of debugging I cannot understand why. I am currently using OpenTK 1.1.2225 and ...
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1answer
57 views

Is there any way in open-gl to “bit crush” everything on the screen?

I am making an educational game and am looking for options for a visual effect to show when something is "incorrect". So, I am looking to see if there's an easy way in openGL to temporarily distort ...
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1answer
174 views

Cannot find bug in frustum culling code

I've written some code for frustum culling, but for some reason, it is not working, and i can't find the bug in it... Maybe a bug in the math, somewhere? So, i'm asking you if anyone could check these ...
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1answer
346 views

Pyglet: text.Label().draw to FBO?

I just started OpenGL (PyopenGl) & Pyglet 3 weeks ago, and decided to read the Red Book. So sorry if my question shows my lack of comprehension... My question is: Is it possible to display/write ...
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1answer
215 views

Collision between a sphere and a mesh(height-map)

I am trying to implement a method that detects the collision between a sphere and a mesh and reflects the vector of speed. I have a method, that detects a collision between a sphere and a triangle and ...
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1answer
56 views

Wrong texture position on camera move

When in my game i move my character, the camera follows it. I have no problem drawing this char when it is moving or moving another char when the camera is still. Now, when i move both of them, the ...
3
votes
1answer
447 views

Drawing fonts with LWJGL3 with OpenGL

I'm very sorry if this question has already been answered, but since I've been struggling with this for many days I thought I'd give it a shot here. My goal is to somehow render some text on the ...
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27 views

How should I go about creating a generic Scene object for managing VBO data?

To simplify managing multiple types of data with different shaders and textures, I thought about creating a generic Scene object (is there a name for this?) which would allow me to pre-configure how I ...
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1answer
116 views

What causes seemingly random triangle artifacts in OpenGL?

When switching version of OpenGL from 4.5 to 4.4, I suddenly started seeing these weird random triangles flickering over my scene They move around somewhat randomly and are always pointed towards ...
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1answer
73 views

Is glxinfo saying that the 980 GTX doesn't support a 32 bit depth buffer?

I've been using the glxinfo command (glxinfo -v) to explore the supported framebuffer configurations. There are two values relating to depth, "depth" and "depthsize." According the source, it appears ...
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1answer
201 views

Java OpenGL Perspective matrix not working

I'm trying to render a simple triangle with OpenGL in Java using LWJGL3. Everything is working great, but the projection matrix (perspective) is not working. In C++ I just used to apply the ...
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1answer
48 views

Parsing .OBJ to fit the gldrawelements() call. c++/opengl

I'm struggling trying to get this to work like it should. Ive been able to make an obj loader that fits the glDrawArrays() call, with uv and facenormals, but when trying to modify it to fit ...
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1answer
111 views

OpenGL strange lighting/model problem

I've made a .obj reader in c++ and I've tried rendering some models. I've got the whole concept from here: ...
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2answers
229 views

Render specific part of a texture in OpenGL (2D Sprite Sheet)

I've looked at this answer to find out how to render just a part of a texture: http://stackoverflow.com/questions/6884285/c-opengl-render-part-of-an-image I tried that, but the problem is, this is how ...
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0answers
31 views

Unable to translate the object such that it looks like it is moving

This is the code I'm using in the display function to translate the object. ` while(a<500.0) { glPushMatrix(); glTranslatef(a,0.0,0.0); glScalef(0.5,0.5,0.5); ...
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1answer
19 views

GLSL uniform array with size set by another uniform

Will the follwing GLSL code work? #version 330 uniform int size; uniform float[size]; void main() { //do something }
2
votes
1answer
61 views

Cannot connecting texture to heightmap using mapped uniform location

In my shader program, I have my attributes and uniforms added to a map for each. What I have displayed is a heightmap, but cant seem to connect the graphic texture to display. mUniformList ...
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1answer
584 views

OpenGL Tessellation makes point

A little problem with my tessellation shader. I try to implement a simple tessellation shader but it only makes points. Here's my vertex shader : out vec4 ecPosition; out vec3 ecNormal; void ...
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1answer
234 views

Minecraft Modding - How do I use OpenGL stencil functions alongside the game's GlStateManager?

Note: I am using Minecraft Coder Pack 9.10 for game version 1.8.0 (official release). I am trying to make a multiline text field similar to the game's original net.minecraft.client.gui.GuiTextField. ...
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1answer
63 views

Issue with detecting collisions in Pong

I've been working on making Pong in OpenGL and SDL and currently have both paddles and the game ball set up properly. I have an Object (or Entity) class which is used to instantiate each of the ...
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2answers
50 views

OpenGL [LWJGL3] - Matrix4x4 not rotating correctly

I tried today to make my own matrix4f class because of that LWJGL 3 does not include a class for it. So I arrived at rotation and it does not seem to work. I tried using the old util from LWJGL 2 and ...
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1answer
84 views

OpenGL Applications Bring computer to halt

Whenever I run any application that utilizes the OpenGL interface, my entire computer comes to a halt, but it doesn't do this when it utilizes the DirectX interface. I run both Linux (Ubuntu 15.10) ...
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votes
2answers
514 views

Signed Distance Fields: How are different colour channels used to improve output of sharp corners?

The naive approach to implementing signed distance field font rendering suffers quality issues where sharp corners get softened (either outward- or inward-facing corners, i.e. convex or concave ...
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1answer
285 views

Trying to implement Camera

I'm trying to implement a Camera class in order to walk and look on the world as follow: #ifndef _CAMERA_H_ #define _CAMERA_H_ #include <glm\glm.hpp> class Camera { public: Camera(); ...
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1answer
72 views

CPU and RAM usage in OpenGL too high in Swift

My game is set up so the the display controls the game loop, usual in Cocoa. The callback function calls run() which is this. The thing is, the thread running the callback is using 63% CPU and the RAM ...
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1answer
91 views

Should I always prefer a Uniform Buffer Object to a uniform variable for per-model uniforms in OpenGL?

I was looking for a way to update uniforms for all of my scene objects efficiently and I came across the following gamedev stackexchange question, where the top answer gives a bonus tip. It states: ...
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0answers
52 views

World texturing techniques in FPS game

Texturing for small objects (pickups and enimies) can easily be done UV-unwrapping the model, and use a texture of reasonable size to make the model look good. But how can texturing be done for the ...
4
votes
1answer
467 views

Using textureGrad for anisotropic integration approximation

I'm trying to develop a real time rendering method using real time acquired envmap (cubemap) for lightning. This implies that my envmap can change as often as every frame and I therefore cannot use ...
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2answers
61 views

What does a perspective projection matrix look like in OpenGL?

I've been trying to construct a perspective projection matrix myself and finding it extremely difficult. I realize that a perspective projection matrix is by default a frustum in OpenGL 3.3+ that is ...
1
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2answers
130 views

Cumulative transformation matrices for hierarchical object transformations

I'm having a small issue with my design for hierarchical 3D objects. I'll try to sum things up concisely. Every object has a vector3 for its position, scale, and rotation, as well as a std::vector of ...
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2answers
42 views

OpenGL perspective matrix far plane

The near plane clips at exactly the value I set just fine but instead of clipping at 1000 the far plane clips at 1. Here is the code for the projection matrix: public static Matrix4f ...
2
votes
1answer
170 views

Instanced rendering with ARB_vertex_attrib_binding

I'm trying to separate the vertex format specification from the vertex data. I was able to do that for the mesh vertices successfully. For instanced rendering I wanted to further separate the instance ...
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2answers
213 views

Fragment shader compiling in webGL but not in OpenGL

I am programming in Haxe (language compiling to multiple platforms) and I have written some shaders. My fragment shader runs fine in html5, but when I try to compile for native (OS X and/or Neko, a ...
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1answer
49 views

How do animation works with mesh?

I'm currently developing a game using OpenGL and my dev has run into a small problem. I'm having some problems understanding how "array of vectices works with animated object". For example, if we have ...
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2answers
31 views

glUniformMatrix4fv - INVALID OPERATION?

I'm attempting to manually setup a matrix in my vertex shader purely because I like to learn as much as possible about anything I do usually. So the problem is that I'm getting an ...