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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1answer
137 views

Should all primitives be GL_TRIANGLES in order to create large, unified batches?

Optimizing modern OpenGL relies on aggressive batching, which is done by calls like glMultiDrawElementsIndirect. Although glMultiDrawElementsIndirect can render a large number of different meshes, it ...
0
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1answer
64 views

Can you specify which VBO/EBO to use with glDrawElements?

I'm creating a voxel-like game. I'm not sure if I am using VBO/EBO's correctly. I am creating a new VBO & EBO for every chunk. This is done once, but chunks call a render function in every block ...
1
vote
1answer
105 views

How to create a regular grid of triangles correctly?

I am trying to create an terrain using opentk/opengl. I have a problem with the VBO/IBO. I think a picture of the problem is the best way to show it: I dont understand why the last triangle of a ...
1
vote
2answers
89 views

Accessing uniform variables from a Cg shader in OpenGL

I am trying to implement a simple PC program with OpenGL, using mandatorily Cg shaders (no Unity whatsoever). I have found some tips on this page http://bobobobo.wordpress.com/2008/10/05/cg-1/ and ...
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3answers
398 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 ...
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0answers
19 views

Manual occlusion culling with glDrawElements [duplicate]

How should I go about doing occlusion culling with glDrawElements? I am dealing with voxel-like terrain. I want to avoid drawing the faces that are facing another block. I just don't know how to ...
1
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2answers
115 views

Keeping ratio the same across devices on fixed screen game

My game is an Android game using OpenGL ES 2.0 (But this question could apply to any platform). I have read many questions on here regarding ratio management, and also read many tutorials outside of ...
1
vote
1answer
83 views

Normal Mapping space confusion

I've been reading today about normal mapping. Up to now, the only normal mapping I encountered was with maps already in world space so I just extracted the info from the texture and transformed them ...
0
votes
2answers
89 views

Was there any equivalent of glVertex3f in Direct3D?

I know that OpenGL's Vertex3f is a bit old but I can't find any information about suitable equivalent for that function that was used in DirectX. Was there any equivalent in DX?
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0answers
94 views

How to export blender coordinate to be used in Android OpenGLES

I'd like to create my personal light-weight Android 3D engine to show 3D animation configured by Blender. I have successfully loaded the Blender-created 3D models by OpenGL ES on Android. Now, I'd ...
0
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0answers
94 views

FBX SDK Colors problem

I've imported control points, normals, and indices successfully and now i'm trying to import vertex colors, but something is not right. Here's the code: FbxLayerElementMaterial* ...
0
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1answer
69 views

Having trouble with projection matrix, need help [on hold]

I'm having trouble with what appears to be the projection matrix. Given a wide enough of a screen, when a cube is on the left and right most edge, the left or right wall will appear stretched to the ...
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0answers
18 views

How to switch a view off and on again while retaining key event input

I have a couple of views in my app - my main activity and a separate activity which is used for high scores. What I need to know is how I can 'get rid' of one of the views temporarily, and then bring ...
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votes
1answer
90 views

Combine Two Shader Program [closed]

For my android application, I want to apply brightness and contrast shader on same image. At present I am using gpuimage plugin. In that I found two separate program for brightness and contrast as ...
0
votes
1answer
48 views

Render on other render targets starting from one already rendered on

I have to perform a double pass convolution on a texture that is actually the color attachment of another render target, and store it in the color attachment of ANOTHER render target. This must be ...
10
votes
1answer
300 views

Rendering only a part of the screen in high detail

If graphics are rendered for a large viewing angle (e.g. a very large TV or a VR headset), the viewer can't actually focus on the entire image, just a part of it. (Actually, this is the case for ...
1
vote
2answers
163 views

OpenGL flickerinng near the edges

I am trying to simulate particles moving around the scene with OpenCL for computation and OpenGL for rendering with GLUT. There is no OpenCL-OpenGL interop yet, so the drawing is done in the older ...
2
votes
0answers
36 views

FBX Importer - Vertex Color

I imported vertex positions, indices and normals successfully in OpenGL using fbx sdk, but I just can't figure out how to import vertex colors. I tried to fetch the pointer to array of colors trough ...
1
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0answers
77 views

Creating a voxel chunk with a VBO - How to translate the coordinates of each block and add it to the VBO chunk?

I'm trying to make a voxel engine similar to minecraft as a little learning experience and a way to learn some opengl. I have created a chunk class and I want to put all of the vertices for the whole ...
2
votes
1answer
224 views

OpenGL - have object follow mouse

I want to have an object follow around my mouse on the screen in OpenGL. (I am also using GLEW, GLFW, and GLM). The best idea I've come up with is: Get the coordinates within the window with ...
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votes
0answers
97 views

OpenGL Drawing textured model (OBJ) black texture

I'm using OpenGL, Glew, GLFW and Glut to create a simple game. I've been following some tutorials and I have now a good model importer with textures (from ogldev.atspace.co.uk) but I'm having an ...
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votes
2answers
58 views

GLSL Normals not transforming propertly

I've been stuck on this problem for two days. I've read many articles about transforming normals, but I'm just totaly stuck. I understand choping off W component for "turning off" translation, and ...
0
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0answers
121 views

Libgdx - 2D Mesh rendering overlap glitch

I am trying to render a 2D circle segment mesh (quarter circle)using Libgdx/Opengl ES 2.0 but I seem to be getting an overlapping issue as seen in the picture attached. I cant seem to find the cause ...
0
votes
1answer
115 views

How to remove seams from a tile map in 3D?

I am using my OpenGL custom engine to render a tilemap made with Tiled, using a well spread tileset from the web. There is nothing fancy going on. I load the TMX file from Tiled and generate vertex ...
1
vote
1answer
112 views

Are there any reasons to use Legacy (2.X) OpenGL?

The benefits are well documented of the Modern OpenGL 3.X & 4.X API's, but I'm wondering if there are ANY benefits to keeping with the old OpenGL, Or if learning OpenGL 2.X is a complete waste of ...
1
vote
1answer
59 views

I don't understand why one of my vbo is overwritten by another

to create a vbo I use this function: public void loadVBO(){ vboID = GL15.glGenBuffers(); GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboID); ...
3
votes
1answer
153 views

Open GL perspective projection vs orthographic projection

I am trying to build an engine using OpenGL however I have a question about the kind of projection to use. For a 2D game should I use a perspective projection or an orthographic projection? If I ...
0
votes
1answer
110 views

What is wrong with my specular phong shading

I'm sorry if this should be placed on stackoverflow instead however seeing as this is graphics related I was hoping you guys could help me: I'm attempting to write a phong shader and currently working ...
1
vote
0answers
43 views

Normal map lighting bug in bottom right quadrant [closed]

I am currently working on getting normal maps working in my project, and have run into a problem with lighting. As you can see, the normals in the bottom right quadrant of the lighting isn't ...
1
vote
1answer
49 views

Depth Map resolution shifting

the problem is with shadow mapping as you can see, actually it works fine but in a certain condition that the Depth Map size must be equal to the size of rendering buffer, I use an infinite ...
1
vote
1answer
41 views

How should I handle a modelview stack with multiple shader programs involved?

I'm building a framework where each object has an associated program and each object has a 'draw' method. What is the best choice, to have a single modelview stack handled by a Renderer class or to ...
15
votes
2answers
1k views

Camera vs Viewport

I'm don't have a clear understanding of what precisely is the difference between the camera coordinates and the viewport coordinates. Can anyone please clarify?
0
votes
2answers
56 views

What is the correct way to reset and load new data into GL_ARRAY_BUFFER?

I am using an array buffer for colors data. If I want to load different colors for the current mesh in real time what is the correct way to do it. At the moment I am doing: glBindVertexArray(vao); ...
2
votes
1answer
181 views

draw fog of war using shaders

I am making a RTS game, and I'd like some advice on how to best render fog of wars, given what I'm already doing. You can imagine this game as being a classic RTS like Age of Empires 2, where the fog ...
1
vote
0answers
125 views

Which will be better for a beginner, SDL, SFML or OpenGL? [closed]

I want to make games.For now simple 2D games, but I don't know from where to start. I "know" C++, but i havent worked with classes.I want to begin with game development and I searched in the internet ...
2
votes
4answers
266 views

OpenGL setup on Windows

I have been trying to use OpenGL for two days now. First on Mac, then on Windows. The problem with Mac is that it doesn't support the newer versions of OpenGL. I ran a tutorial that actually did get ...
5
votes
2answers
188 views

How to use OpenGL functions from multiples thread?

I'm writing a small game using OpenGL. I'm implementing basic networking in this game and I'm facing a problem. I have a thread in my client socket class that check for available data, when there ...
0
votes
1answer
76 views

OpenGL ES 1 Pixel Error?

I am developing a game on android using OpenGL ES 1.0 for Android OS. It is a 2d game using a simple Orthographic projection and textures for the sprites. One of these textures has a small line (it ...
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votes
1answer
81 views

How do I put different textures on different walls? LWJGL

So far I have it so you are running around in a box, but all of the walls are the same texture! I've loaded up other textures for the walls (I want the walls a different texture than the floor) but it ...
1
vote
1answer
689 views

OpenGL - Calculating camera view matrix

Problem I am calculating the model, view and projection matrices independently to be used in my shader as follows: gl_Position = projection * view * model * vec4(in_Position, 1.0); When I try to ...
2
votes
1answer
305 views

OpenGL 4D textures with bilinear interpolation

I want to use and interpolated 4D texture in OpenGL, i.e. a texture that is accessed with a texture coordinate vector (s, t, p, q) and interpolated linearly in every texture coordinate. The extension ...
1
vote
0answers
89 views

Different way to pass uniforms to seperate draws in glMultiDrawElementsIndirect

Given OpenGL version 4.3 and GLSL 430, what would be the best way to pass a matrix to each model in a draw call to glMultiDrawElementsIndirect? I am thinking of going the way of a TBO and indexing it ...
1
vote
0answers
92 views

Android: Hardware Scaler

I was reading through this: using-hardware-scaler-for-performance and am a little confused by it. It says all you need to do to invoke the scaler is to set it like so: surfaceView = new ...
1
vote
1answer
182 views

Render 2 images that uses different shaders

Based on the giawa/nehe tutorials, how can I render 2 images with different shaders. I'm pretty new to OpenGl and shaders so I'm not completely sure whats happening in my code, but I think the shaders ...
0
votes
0answers
51 views

Issue with turntable rotation openGL

I am trying to implement turn table like rotation in my openGL app. In turn-table like rotation, z-axis is not supposed to roll. But in my app z-axis rolls like anything when I try to rotate the ...
0
votes
0answers
93 views

Help with instancing: seg fault with glVertexAttribDivisor

I'm trying to get the basics of instancing in OpenGL 3.3 and failing miserably. I'm starting with the Jason McKesson's Depth Buffering tutorial, then modifying it so that only the ...
1
vote
1answer
86 views

Why are my objects rotating with my camera?

I am working with this C# library that wraps OpenGL. I am trying to understand why my objects in the scene are rotating as I yaw my camera (view matrix). Here is an image where I have 4 separate ...
0
votes
1answer
210 views

Create 2D sprites with libGdx using a shape and a texture separately

I am creating a 2D game with LibGdx that will have creatures that are generated from dozens of characteristics with potentially millions of unique combinations. For each segment of each creature, I ...
0
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1answer
105 views

Making particles accelerate toward a mouse point

I'm currently working on a particle simulation program that makes pixels move towards a mouse point continually accelerating, but i'm running into some math issues. Currently my particle will ...
0
votes
2answers
75 views

Trouble getting shadow maps working

I am trying to implement shadow maps in my game following this tutorial. For some reason, the light is not being occluded. In the above screenshot, the big white sprite in the foreground is a ...