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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19 views

Bounding box center after transformation - want degree values for GUI

Similar to my previous question, I have a bounding box that I have transformed and scaled. Now, I want to get its center by doing this operation and store this value. bbCenter = glm::vec3(bbMin_x + ...
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0answers
37 views

Third Person Camera OpenGL

I am currently working on my first OpenGL project for school, some demo code was given to us and now we have to build upon it. It's a space game and here is part of the Player Class (ship.c, just a ...
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1answer
29 views

Providing texture coordinates and using indexed drawing at the same time

Please consider the following vertex structure struct vertex { vec3 posL, normalL; }; Using this vertex layout, we can provide the vertex data in an interleaved way, i.e. ...
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2answers
76 views

glGenVertexArrays causes crash

My code keeps crashing at runtime, I have done some creative debugging and determined that it was the glGenVertexArrays that was causing the crash, I've looked around and come across some answers that ...
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0answers
35 views

OpenGL camera Rotation Matrix & view Transformations [on hold]

Recently i implemented a simple Opengl program that composes of a scene of objects, i've applied most of the transformation & projection matrices, in such away that i am able to rotate transform ...
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0answers
31 views

World, View, Projection concept - history [on hold]

I've got some unusual question, actually I would like to know something about the history of the World-View-Projection concept. Where did it come from? When was it used first? Does it exist since DX ...
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1answer
52 views

Most efficient way of brighten and darken sprites with OpenGL > 2.0

So I have been shading (brighten/darken +adding color) my sprites by using glTexEnvf with GL_MODULATE and GL_ADD and a vertex color. I only had to rebind the batch every time I needed to change from ...
2
votes
1answer
33 views

How do I fit the camera frustum inside directional light space?

I'm trying to improve the coverage of a shadow map for a directional light. Currently, it works great if the camera is looking straight down. However, if the camera is close to the ground and looking ...
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0answers
31 views

Focus a turntable style camera on an object

I have a turntable style camera in the maya / blender / alembic / opensubdiv example. I want to be able to match the camera translation to any objects translation pivot point in the scene and then ...
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0answers
23 views

Keeping relative size with different resolution

I'm making a GUI system and want the components having a konstant relative size, even if I'm changing the resolution. Since I'm using the relative OpenGL coordinates to place them, there is no ...
0
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0answers
29 views

Loading Wavefront Data into VAO and Render It

I have successfully loaded a triangulated wavefront(.obj) into 6 vectors, the first 3 vectors contain the locations for vertices, uv coords, and normals. The last three have the indices stored for ...
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0answers
33 views

Why am I not getting an sRGB default framebuffer?

I'm trying to make my OpenGL Haskell program gamma correct by making appropriate use of sRGB framebuffers and textures, but I'm running into issues making the default framebuffer sRGB. Consider the ...
3
votes
1answer
63 views

Should my GLSL Shader object/wrapper encapsulate loading/setting a VertexArrayObject?

I am working on a 2D game in C++, with a simple rendering layer over OpenGL. I have a wrapper for GLSL shaders and shader programs, these wrappers encapsulate shader objects into C++ classes and ...
4
votes
1answer
178 views

OpenGL rendering looks squeezed

I am rendering bunch of cubes of unit size, but for some reason they look like they are squeezed a bit in the screen-space y axis. Why is this? My projection matrix: Projection = ...
3
votes
3answers
132 views

Make openGL program only update every 1/60 seconds

I'm learning C++ and openGL and have this program as a result from tutorials and playing around. The problem is that the main loop is running at "full speed", making the program unnecessarily cpu ...
-1
votes
0answers
21 views

LWJGL camera rotation is pivoting around original point instead of around where it has been translated (w/ glRotatef)

I've been playing about with LWJGL and I've encountered a problem. When I move the player's camera and then rotate it, it appears to pivot around where the player originally was. How do I make it so ...
1
vote
1answer
89 views

Performing manual clipping in OpenGL

I'm learning OpenGL and I understand that OpenGL performs clipping as part of the pipeline, but is it a good idea to also perform manual clipping? By manual clipping, I mean not asking the GPU to draw ...
0
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0answers
37 views

Mouse input that 'sucks in' particles [on hold]

I'm having trouble figuring out the equations behind the title, I did exactly this using OpenGL's fixed function pipeline, but while transferring this over to the programmable pipeline i'm running ...
0
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2answers
50 views

What dimensions should you use for a perspective projection frustum?

What dimensions should you use for a perspective projection frustum? Initially I created a perspective matrix based on the width and height of the screen, with a calculated zNear value based on a ...
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1answer
33 views

LWJGL Resize window and glTranslate breaking screen resolution

I'm trying to make a 2D Tile RPG game with LWJGL but I'm having a problem with the display resizing. I want the user to be able to re-size the window to whatever size they want just by expanding it ...
2
votes
4answers
239 views

Why would you use software rendering over hardware rendering, today?

As opposed to CPU or software rendering I assume? Wouldn't generally all current rendering be GPU based, seeing as you would be using OpenGL or Direct X? Could someone give me some info here, can't ...
0
votes
2answers
130 views

OpenGL - How can I make the edges of this textured circle smoother?

I'm building a game and I've applied a certain texture (RAW file) to a circle (GL_POLYGON) in OpenGL. It loads correctly, with the right size and all, but the edges seem a bit jagged and I would ...
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votes
1answer
84 views

C++ SDL2 OpenGL Rendering Problems [closed]

I just started with SDL2 and OpenGL in C++ and I am having some trouble rendering a triangle. The triangle I want to draw renders on the screen, but it is black. I tried added some shaders, but they ...
1
vote
1answer
209 views

How can I implement beam effects like these?

I am interested in the techniques I could use to create the following effects: Can I accomplish this with a particle system or a series of texture quads, or what? You can see this effects in ...
0
votes
1answer
96 views

Render scene twice in OpenGL, overlay second render with tranparency

Is it possible to render two scenes (same scene with different setups) without any alpha, and after that is done just overlay the result from the second render on top of the first layer with a static ...
0
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3answers
99 views

OpenGL: glRotatef cause performance drop while rotating -x and -y

I have made a rotating cube and I got some performance drops while using two glRotatef calls. So basically this code is giving me 80FPS: //code 1 GLrotate_x += 0.4f; GLrotate_y += 0.4f; ...
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0answers
33 views

Using multiple uniform blocks in OpenGL

I'm using OpenGL with JOGL and want to use two unfirorm blocks in my vertex and pixel shaders. The following GLSL-Code shows the definitions:- uniform perObject { Material uMaterial; mat4 ...
0
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2answers
141 views

Do Java and Actionscript use OpenGL?

As far as I know there are only 3 base graphics libraries on Windows, the GDI, OpenGL and DirectX, is that correct, so that means that Java, Actionscript and all language use one of these 3 libraries ...
3
votes
0answers
90 views

OpenGL Shadow Mapping from directional light [on hold]

I have read this tutorial: http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-16-shadow-mapping/ I wonder, is this the current best technique for generating shadows in an arbitrary 3D ...
0
votes
1answer
99 views

OpenGL: How to improve the performance of rendering context [on hold]

I have written a benchmark program that compares the performance of OpenGL and DirectX libraries. The problem is that OpenGL gets much lower performance than Direct3D. At the end the program generates ...
0
votes
0answers
28 views

Get closed ring around a mesh passing through given points

Suppose I've some points on a mesh (2+) that can be anywhere on the mesh, suppose for example these (ignore the small points, just consider the sphere): http://i.stack.imgur.com/nDzW3.png (sorry ...
2
votes
1answer
63 views

Possible to create transparency shader which doesn't stack alpha values

The image above best demonstrates what I'm trying to achieve. It's a transparent shader for objects, but wherever the objects with this shader intersect they don't add together but simply merge with ...
0
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0answers
79 views

Irrlicht - Camera rotation like FPS

I'm constructing a game in OpenGL and initially I started using GLUT for the general purposes. However, later on I bumped over the problem of 3D model import and, after so many time trying to import ...
0
votes
1answer
79 views

Why do I have to switch T(v) texture coordinates while importing OpenGL to Direct3D?

I am importing my code from OpenGL to Direct3D. My D3DTS_PROJECTION uses D3DXMatrixPerspectiveFovRH, and my D3DTS_VIEW uses D3DXMatrixLookAtRH to set a view equal to OpenGL's view. My question is why ...
0
votes
2answers
53 views

Clamping large content to smaller area

I'm using OpenGL (with LWJGL) in Java, but the question is language independent. I have some region (a rectangle for simplicity), and, let's say, a big tiled map which I want to show in this area. ...
2
votes
1answer
58 views

OpenGL: missing GL_SPECULAR light on the texture

I'am missing specular lighting on the texture. I have #include <GL/glext.h> in the project, so basically I used glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL_EXT, GL_SEPARATE_SPECULAR_COLOR_EXT); ...
2
votes
1answer
54 views

How to store an array into a texture and sampler the texture in vertex shader correctly?

I'm a new learner about OpenGL and GLSL. I'm coding a program in which i wanna store a group of datas in a texture and get the data by sampling the texture in vertex shader. Then i want to set the ...
1
vote
1answer
51 views

How to save am image of a screen using JOGL

Hope this is a better place to ask things like this. I have a 2D scene with some sprites drawn in Swing frame. I need them to be saved as an image. The problem is every tutorial I found seem to be ...
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0answers
4 views

Code::Blocks undefined reference to “*” [migrated]

Like the title says, I'm getting multiple build errors using C::B, all are saying undefined reference to '*'. I'm trying to build a program using OpenGL, GLFW, and GLEW. The top three things that it ...
1
vote
2answers
66 views

Loaded OBJ Model Will Not Display in OpenGL / C++ Project

I have been experimenting with new effects in game development. The programs I have written have been using generic shapes for the visuals. I wanted to test the effects on something a bit more ...
1
vote
1answer
65 views

OpenGL and atlas

I'm trying to draw element from a texture atlas with OpenGL ES 2. Currently, I'm drawing my elements using something like that in the shader: uniform mat4 uCamera; uniform mat4 uModel; attribute ...
1
vote
1answer
32 views

Correcting Lighting in Stencil Reflections

I'm just playing around with OpenGL seeing how different methods of making shadows and reflections work. I've been following this tutorial which describes using GLUT_STENCIL's and MASK's to create a ...
1
vote
1answer
29 views

Having trouble setting color in fragment shader

For some reason, the color isn't applying to the object. Here's my fragment shader code. There's probably something obvious wrong with it that i'm not seeing. #version 330 core out vec3 Color; ...
0
votes
0answers
75 views

Moving objects smoothly, bad perfomance

I just finished developing my mini-game on Android and I got some questions about perfomance and generally "how to": If I have 25+ objects on the creeen (just a polygon with 7-8 angles) its starts to ...
-1
votes
0answers
24 views

transparency in textures - color from background [duplicate]

I am making new thread as old one was closed. Transparency in opengl - texture with alpha, color from background As you see the problem wasn't solved as texture takes color from polygon that I am ...
0
votes
1answer
77 views

How does OpenGL determine different outputs with shaders?

Lets say I have this GLSL code: #version 330 out vec4 outputColor; void main() { float lerpValue = gl_FragCoord.y / 500.0f; outputColor = mix(vec4(1.0f, 1.0f, 1.0f, 1.0f), ...
0
votes
1answer
62 views

Transparency in opengl - texture with alpha, color from background [duplicate]

I have to draw texture with transparent areas on square. But I don't want this transparencies to take color from this polygon, but from the background. Do you have any good tutorial to achieve it? ...
0
votes
1answer
71 views

Getting the Ray position from View and Projection Matrix

I'm having some trouble calculating the direction and position of the ray from my matrices. I have tried some things such as: private Vec3 getPick(Mat4 projection, Mat4 view) { Mat4 ...
2
votes
1answer
88 views

How to make OpenGL rendering resolution independent from its window context resolution?

Can the rendering resolution of OpenGL and the window size (at least for the Windows OS) be separated? For example, I may only want to render at 400x300 resolution, but I want my window size to be ...
0
votes
1answer
71 views

Correct GL settings to mix 2D and 3D rendering

I'm programming a 3D game engine with 2D GUI. The GUI objects have partially transparent textures and the transparency works more or less. The sky color is rendered in transparent areas of the ...