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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3
votes
2answers
1k views

Does Monogame on Windows Desktop use OpenGL or DirectX by default?

if i use monogame 3.0 beta on windows desktop, does it use the directx renderer (sharpdx) or the opengl renderer by default? if it uses directx is there away to make sharpdx call directly? thanks!
-1
votes
1answer
163 views

OpenGL glMatrixMode rotation

I'm stuck on trying to figure out how to rotate the viewport(or camera). So far I've figured out I need to use the function glRotatef and glMatrixMode(GL_MODELVIEW). But I have no idea how to apply ...
9
votes
1answer
424 views

Mesh manipulation on GPU vs CPU

Just a bit curious - where do you perform mesh manipulations, on the CPU or in the shader? I've been doing everything on the CPU and a friend suggested moving things on to the GPU side. If you're ...
1
vote
1answer
206 views

Multisampled Texture

i have some doubts with multisampled textures. In fragment shader, how to pass multiple samples? We use glTexImage2DMultisample instead of glTeximage2D. so, how to upload texture data? I want to ...
1
vote
0answers
119 views

Using GL_INT_2_10_10_10_REV in glVertexAttribPointer()

Can anybody tell me how exactly do we use GL_INT_2_10_10_10_REV as type parameter in glVertexAttribPointer() ? I am trying to pass color values using this type. Also what is the significance of "REV" ...
1
vote
1answer
356 views

OpenGL Depth Buffer/Coordinate issue with SFML

For some reason, my coordinate system in OpenGL is getting all messed up with depth. When I put something more than 1 unit away from zero (in terms of the Z coordinate), I can't see the object. ...
1
vote
3answers
463 views

Event Based Render / Update Loop

I'm working on a few game dev tools which use OpenGL or DirectX to render 3D models (viewing). Consider your favorite 3D modeling software package (Softimage, Maya, 3DS Max, modo, etc.). Note that ...
2
votes
1answer
233 views

Procedurally generating terrain in dead time before buffer swap

I'm using OpenGL/C++ in Windows, and my main loop looks like this: GLboolean done = GL_FALSE; auto_ptr l_world(new World); l_world->Init(); while (!done) { if ...
5
votes
2answers
2k views

OpenGL: Is it possible to use VAO's without specifying a VBO

On all the tutorials I can find about VAO's (Vertex Array Objects), they show on how to use them by configuring vertex attributes and binding a VBO (Vertex Buffer Object). But I want to create a VAO ...
1
vote
1answer
409 views

OpenGL ModelView matrix

Hello I am trying to understand matrix operations behind OpenGL and I have some questions. 1- When we first create a simple window using glut and opengl, we use such a command below to draw a simple ...
1
vote
0answers
190 views

How to make an oscillation move on opengl qt

I'm trying to make a character make an oscillation move. That is, the character will start by rotating to a certain angle, say 60 degrees, and then slowly come back to an upright position then rotate ...
2
votes
1answer
65 views

Precomputing SSAO causes driver timeout

I was trying to do a pre-calculations of an SSAO effect by rendering normals and depth on a cubemap and doing a second ssao pass on each of these faces. The problem is I'm getting a timeout: "the ...
1
vote
1answer
283 views

Collision Detection Tips

I need collision detection for my 3D racing game but it isn't going well right now. I think I understand the concept of testing boxes and generating a response, however implementation part is a ...
1
vote
0answers
111 views

iPhone collada object

Hi I am new to game development. I see many examples and tried myself like displaying triangle, cube etc. Now I am looking to render a Collada object. So I created a Collada object using Google Sketch ...
5
votes
1answer
162 views

Blend multiple regions from same texture atlas

I'm representing terrain in my game as a grid with at each node a composition, for example 100% rock, or 50% grass, 50% soil. I'd like to use this composition vector to blend textures together. I'm ...
1
vote
1answer
342 views

Apply portion of texture atlas

I'm trying to write a shader that only maps a portion of a large texture to my sprite and I'm getting a strange behaviour with my current code. This is what I have right now: Texture atlas ...
0
votes
1answer
171 views

My VBO is always empty [closed]

I'm trying to render an obj file with a VBO but I have some problems. I have a Renderer object that has a method "setPositions()" that simply stores some data from a QVector to a VBO. The render part ...
2
votes
3answers
400 views

Should I use OpenGL while working with C++? [closed]

I am completely new to programming and game development for that matter. I am using the C++ software to create my Game Engine with the help of a beginners guide. I noticed it has a OpenGL option when ...
3
votes
1answer
131 views

Queries regarding Geometry Shaders

I am dealing with geometry shaders using GL_ARB_geometry_shader4 extension. My code goes like : GLfloat vertices[] = { 0.5,0.25,1.0, 0.5,0.75,1.0, -0.5,0.75,1.0, ...
11
votes
1answer
741 views

OpenGL - white edges on cubes

In a minecraft-like game I'm making, I get white edges on my cubes: It is much more noticeable in darker textures. The textures are being setup like this: glTexParameteri(GL_TEXTURE_2D, ...
1
vote
0answers
326 views

Access Violation when trying to bind Vertex Object Array [closed]

I've just started digging into OpenGL and I've run into a problem trying to set a VOA. It's giving me a run-time error of : An unhandled exception of type 'System.AccessViolationException' At ...
4
votes
1answer
445 views

Vertex data split into separate buffers or one one structure?

Is it better to have all vertex data in one structure like this: class MyVertex { int x,y,z; int u,v; int normalx, normaly, normalz; } Or to have each component ...
2
votes
1answer
238 views

VBO and shaders confusion, what's their connection?

Considering OpenGL 2.1 VBOs and 1.20 GLSL shaders: When creating an entity like "Zombie", is it good to initialize just the VBO buffer with the data once and do N glDrawArrays() calls per each N ...
0
votes
1answer
290 views

Picking a suitable resolution for a modern low-res game?

I'm working on a 2D game project right now (using SFML+OpenGL and C++) and I'm trying to figure out how to go about choosing a resolution. I want my game to have a pixel resolution that is around that ...
3
votes
1answer
336 views

how to organize rendering

I use a deferred rendering. During g-buffer stage my rendering loop for a sponza model (obj format) looks like this: int i = 0; int sum = 0; map<string, mtlItem *>::const_iterator itrEnd = ...
2
votes
1answer
306 views

Tutorial on OpenGL texture formats

Looking at the documentation glGetTexImage(), one can see that there are plenty of available texture formats. GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_1D_ARRAY, GL_TEXTURE_2D_ARRAY, ...
-2
votes
1answer
120 views

Should I glTranslatef to the object then glTranslatef back to the origin or is there another way?

For example: glTranslatef(x,y,z); //x, y and z are the position of this cube glBegin(GL_QUADS); glColor3f( 1.0, 1.0, 1.0 ); glVertex3f( 0.5, -0.5, 0.5 ); glVertex3f( 0.5, 0.5, 0.5 ); ...
2
votes
1answer
169 views

Shadow cubemapping?

I am working on a game with C++ and OpenGL 3.2. I have successfully implemented directional shadow maps and now I'd like to upgrade them to shadow cube maps (for point lights). I've done some Googling ...
0
votes
0answers
357 views

3D texture coordinates for a cube

I want to use glTexImage3D with cube. what will be the texture coordinates for it? i am using GL_TEXTURE_3D as target. I tried with u v coordinates same as 2d texture coordinates with z component ...
4
votes
1answer
106 views

What OpenCL video cards (or FPGAs) features are needed for high speed multiplication?

I'm benchmarking some cryptographic related software and am looking for video cards that are better at parallel multiplication vs parallel addition. Is there any prior work that would graph video ...
2
votes
1answer
59 views

How to transform a subset of a vertex in a vertex buffer?

float linePos[6]={0.0f,5.0f,0.0f,0.0f,30.0f,0.0f}; ... glGenBuffers(1, &buffer); glBindBuffer(GL_ARRAY_BUFFER, buffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*2, linePos, ...
1
vote
1answer
625 views

Image loaded from TGA texture isn't displayed correctly

I have a TGA texture containing this image: The texture is 256x256. So I'm trying to load it and map it to a cube: #import <OpenGL/OpenGL.h> #import <GLUT/GLUT.h> #import ...
3
votes
3answers
1k views

What method replaces GL_SELECT for box selection?

Last 2 weeks I started working on a box selection that selects shapes using GL_SELECT and I just got it working finally. When looking up resources online, there is a significant number of posts that ...
2
votes
2answers
1k views

Move Camera Freely Around Object While Looking at It

I've got a 3D model loaded (a planet) and I have a camera that I want to allow the user to move freely around it. I have no problem getting the camera to orbit the planet around either the x or y ...
3
votes
1answer
1k views

How are vertex shader outs sent as inputs to the fragment shader?

I'm learning some OpenGL 3.2 way of doing things and I think it's quite great, I'm actually understanding more of shaders and non-fixed pipeline in 1 week rather than those 2 years I tried to learn ...
15
votes
2answers
511 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 ...
1
vote
1answer
211 views

fragment shader with SNORM textures

I want to apply SNORM texture by using GL_TEXTURE_3D as a target, what will be the fragment shader for the same? Also, what should be the data type of texture data?
-1
votes
1answer
458 views

Problem rendering VBO [closed]

I'm developing a game engine using OpenTK. I'm trying to get to grips with the use of VBO's. I've run into some trouble because somehow it doesn't render correctly. Thus far I've used immediate mode ...
1
vote
1answer
517 views

Octrees and Vertex Buffer Objects

As many others I want to code a game with a voxel based terrain. The data is represented by voxels which are rendered using triangles. I head of two different approaches and want to combine them. ...
4
votes
2answers
811 views

How is the gimbal locked problem solved using accumulative matrix transformations

I am reading the online "Learning Modern 3D Graphics Programming" book by Jason L. McKesson As of now, I am up to the gimbal lock problem and how to solve it using quaternions. However right here, ...
1
vote
1answer
49 views

What files and libraries do I need for OpenGL and controls

I am starting a 3D game, however I find OpenGL file system very confusing. OpenGL package doesn't have one file, other package doesn't have another, so I need a summary of what files do I need to ...
1
vote
1answer
137 views

Animate multiple entities

I'm trying to animate multiple(3) entities using one model(IQM format). It's working but performance is really bad because I'm calling animate function for each entity in my game loop (I think ...
3
votes
1answer
198 views

openGL textures in bitmap mode

For reasons detailed here I need to texture a quad using a bitmap (as in, 1 bit per pixel, not an 8-bit pixmap). Right now I have a bitmap stored in an on-device buffer, and am mounting it like so: ...
2
votes
1answer
487 views

How can I pass an array of floats to the fragment shader using textures?

I want to map out a 2D array of depth elements for the fragment shader to use to check depth against to create shadows. I want to be able to copy a float array into the GPU, but using large uniform ...
4
votes
2answers
583 views

Square game map rendered as sphere

For a hobby project of mine I have created a finite voxel world (similar to Minecraft), but as I said, mine is finite. When you reach the edge of it, you are sent to the other side. That is all ...
6
votes
4answers
1k views

Generating triangles from a square grid

I have a 2D square grid of values representing terrain elevations, and I want to generate triangles from that grid to make a 3D view of the terrain. My first thought was to split each square ...
2
votes
0answers
74 views

Everything turning black when pitching down [closed]

Just a quick questions about something that's occurring in my world. Every time I pitch my camera downward, everything starts turning black, and if I pitch upward, everything sort of intensifies. ...
0
votes
1answer
185 views

Y Axis inverted on vertex output

I've got my project running and somehow it seems my vertex y components are inverted. 10 in the positive on Y goes down and 10 negative on the Y axis goes up. I can't find anything with the ...
1
vote
2answers
239 views

Deferred rendering order?

There are some effects for which I must do multi-pass rendering. I've got the basics set up (FBO rendering etc.), but I'm trying to get my head around the most suitable setup. Here's what I'm ...
4
votes
0answers
816 views

OpenGL problem with FBO integer texture and color attachment [closed]

In my simple renderer, I have 2 FBOs one that contains diffuse, normals, instance ID and depth in that order and one that I use store the ssao result. The textures I use for the first FBO are RGB8, ...