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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35 views

How can I generate passive 3D using a consumer level graphics card?

I would like to how to generate packed frames and sent them by HDMI to a 3DTV for passive stereo visualization, using any consumer-grade graphics card. I am working on Linux, and programming in C++. ...
3
votes
2answers
1k views

What does changing GL_TEXTURE_WRAP)_(S/T) do?

I am working through some beginner OpenGL tutorials, and the current one teaches how to apply a texture to a simple rectangle. The tutorial states tells me to set the texture parameters ...
3
votes
4answers
250 views
+50

OpenGL lighting appears to be clamping

I'm experiencing an odd problem where everything placed in front of my light appears black in my scene. This happens on multiple axes. I've searched the depths of the internet to find a solution, but ...
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0answers
14 views

LibGdx Exception

Here is the exception: Exception in thread "LWJGL Application" java.lang.NullPointerException at com.mygdx.test.excav.game.WorldRender.renderTest(WorldRender.java:34) at ...
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1answer
76 views

For Vertex Buffer Steaming, Multiple glBufferSubData VS Orphaning?

I was learning OpenGL recently. In games, we need to update the position of game objects frequently, and they will come in & out of screen constantly. So it means in rendering we need to update ...
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vote
2answers
146 views

Application of classes with critical non-static fields in LWJGL

I'm going to be as specific about this question as I can. Ultimately, how is it that I apply a class that uses non-static fields in LWJGL? More specifically, I know that OpenGL is quite nearly more a ...
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votes
1answer
39 views

Can diffuse and specular component of Phong model shine thru object?

I have been implementing simple 3D engine in OpenGL, mostly based on tutorials by Tom Dalling. I have implemented the Phong lightening model as described in his tutorial, but I see light artifacts on ...
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votes
1answer
41 views

OpenGL Depth Test Errors

I've been working on this problem for a while now. GL11.glDisable(GL11.GL_DEPTH_TEST); GL11.glEnable(GL11.GL_BLEND); GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA); ...
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votes
2answers
39 views

Overload how an object instance of a class is treated when used

So I've made this struct that encapsulates a glm::vec4. This is because vec3s are treated as 16-byte in GLSL, but I don't want to assign a vec4 if I only really need 3 components. Anyway, my question ...
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0answers
40 views

Generating Mesh From Voxel Data [on hold]

I need help converting a 3D array of voxels (The array indexes are the voxel positions) to an actual voxel terrain mesh (float array for vertices, And a int array for indices) So i can render a chunk ...
0
votes
1answer
51 views

Player being covered by glClearColor?

Here is a video of the problem: https://www.youtube.com/watch?v=6vnDOB1Vk4o (this is the game I've been making for fun/practice). You notice, in the beginning of the video, I walk off the map and ...
1
vote
1answer
24 views

Opengl Quad Tessellation Control Shader

I have the generic tessellation evaluation shader for triangles but I need to make it work for quads. Is there any chance someone could explain what is happening here and point me in the right ...
2
votes
1answer
200 views

How do I use unpackHalf2x16?

I'm trying to use (un)packHalf2x16, without success so far. I'm drawing with: glVertexAttribIPointer(0, 2, GL_UNSIGNED_INT, 0, 0); glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vbo); ...
0
votes
1answer
60 views

Uniform Block solve padding/alignment for vec3 in CPU struct

I have a struct on the CPU which I'm sending to a uniform block in my shader. After a bit frustration I finally got it to work. The problem I had was that vec3s are actually treated as 16-bytes, or in ...
0
votes
0answers
36 views

Artifacts rendering high-poly procedural meshes with OpenGL

I am having some issues when rendering some procedural generated meshes. There are some really wierd artifacts when rendering high-poly count meshes (not that much actualy). I have been able to ...
1
vote
1answer
33 views

How to improve Batch Rendering to work with 3D skeletal animation data

I've implemented a batch rendering technique that is described in detail here: http://www.gamedev.net/page/resources/_/technical/opengl/opengl-batch-rendering-r3900 I'd like to extend it now to ...
6
votes
1answer
204 views

Why does accessing a uniform float make my shader more than twice as slow?

My fragment shader was significantly slowed down by a recent change, and I've been trying to understand why. I isolated the main slow-down to accessing a single particular uniform float. If I include ...
1
vote
1answer
72 views

Problems with texture orientation in space

I am currently drawing texture in 3D space and have some problems with it's orientation. I'd like me textures always to be oriented with front face to user. My desirable result looks like ...
-1
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0answers
33 views

C# OpenTK - How to get a Bitmap from a loaded Texture [closed]

After some searching around, I put this code together: public static Bitmap BMPfromTextureID(int id) { int w, h; GL.BindTexture(TextureTarget.ProxyTexture2D, id); ...
0
votes
0answers
41 views

Black screen using frame buffer

I'm trying to use frame buffer to add post effects on my game and I've got a problem: My screen is black every time I'm trying to drawn something in. My scene is simple: A static red box on a black ...
3
votes
1answer
284 views

I want to render some surfaces in GLSL with normal maps, and some without

I have normal mapping working in my game, but I want to only use normal mapping for some surfaces, and not others. Right now, as far as I can tell, my shader is applying an incorrect normal of (0, 0, ...
1
vote
0answers
44 views

Interpolating colors to greenify or blueify a screen fade

I am attempting to duplicate something from a game where the screen basically fades to a color by 'green-ifying' or 'blue-ifiying' the screen. My guess is that it does a linear color interpolation ...
1
vote
1answer
76 views

How can I implement a camera like the one in RotMG?

RotMG, an MMO top-down shooter, takes on a unique 2d-3d style, and has an intriguing camera; The game is obviously 3d, not simply isometric, and if you play the game and turn on camera rotation you ...
1
vote
1answer
51 views

Triangles go missing as Z changes

I'm rendering a height map using shader-based OpenGL (3.3 to be precise). The height map data is from a grayscale bitmap (2D array of bytes). The dimension of the bitmap is 256 x 256. With this data, ...
3
votes
2answers
486 views

How do I crop a camera's viewport?

I'm making an Android game using LibGDX. I would like to render a cropped version of the camera's viewport. Here's an original camera view (in 3ds max): I can get the same view in LibGDX without ...
2
votes
2answers
516 views

Build-time GLSL syntax validation

Is there a way to validate GLSL syntax build-time instead of run-time? My application takes a long time to start and I want to know at the earliest possible stage that my shaders are ok. I'm using ...
0
votes
0answers
25 views

Dynamic VBO update possibly corrupting data?

I want to draw a line between two vertices. On a mouseclick the vertex data will change and I want to update the line to use the new values. I am using a VBO for this and it looks like the update ...
0
votes
1answer
35 views

Is there a builtin way to convert rect to spherical coordinates

This seems like a fairly basic and common problem. Is there a builtin way to achieve it or do i have to write the algorithm on my own?
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votes
0answers
24 views

glBlendFunc() makes primitively drawn quads disappear

i have experienced some issues with glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);. Having this invocation in OpenGL init code makes stuff drawn with the following methods ...
1
vote
1answer
39 views

Alpha blending, transparence and z-ordering

I'm making some tests with alpha blending in a projet and I don't understand something. In my tests I've done something like that and everything look good: Draw blue box first (depth test: true, ...
1
vote
1answer
104 views

Correct multiplication order for a 2D Matrix

I'm currently trying to create a camera and entity/model matrix for my 2D game similar to that of Unity3D. I've already tried to find answers to this question on stackoverflow/gamedev but i couldn't ...
0
votes
0answers
19 views

How to properly transform vertices for a model loaded using Assimp?

When I try to load a DAE model then vertices are not placed correctly. Here's the code snippet I use to load 3D models using Assimp : aiNode* CGameObject::findNode(aiNode* rootNode, const char ...
0
votes
0answers
30 views

When camera moves the textures move and rotate

I recently followed the tutorial at PaulsProjects on shadow mapping. After finishing the tutorial all of my textures seemed to have vanished, then I moved my camera and the texture reappeared. But the ...
1
vote
1answer
254 views

Calculating shadowmap coordinates for cubemap in shading pass?

I'm trying to implement shadow mapping with cube maps. I believe I've done the first stage by filling the cube map, but for the final shading pass I am unsure how to exactly calculate the cubemap ...
0
votes
2answers
38 views

How can I change the value of a matrix uniform in an OpenGL vertex shader?

I'm new at OpenGL. I have a uniform transform matrix in a vertex shader file. I want to modify the matrix by individually assigning each values in the matrix. How can I do that in C++? I learned that ...
0
votes
2answers
95 views

Combine flat and smooth shading with a single model geometry

I need to be able to switch between smooth and flat shading interactively. Is there a way to do this efficiently with a single geometry? For example, smooth shading does not require duplicate ...
2
votes
1answer
173 views

Use different values for Depth Test and Depth Write in OpenGL

Is there a way to use something similar to PolygonOffset to make a depth test more permissive (move fragment depth towards eye) but still write the original depth value to the depth buffer? The only ...
0
votes
1answer
66 views

GLSL: Vertex attribute to int

I'm trying to write a shader which renders a multitextured geometry wihout rerendering the geometry with each texture. In my test I'm not using textures, I just convert the texture index to a color ...
3
votes
1answer
159 views

Do shader program compilers optimise divide-by-PoT-constants to bitshift operations?

So just to restate that, let's say we have this: float f = g / 2; Given the divisor is a constant, will the shader compiler auto-optimise this to a bitshift operation, as some language compilers are ...
2
votes
1answer
300 views

Mesa library vs Hardware accelerated OpenGL for my executable - it's just a linking problem? [closed]

Supposing that i have my program that is targeting a specific OpenGL version, let's say the 3.0, now i want to produce an executable that will support the software rendering with Mesa and another ...
0
votes
0answers
47 views

Tessellation shader pass-through : Nothing displayed

I am trying to set a pass-through tessellation shader and then build on top of that while learning. From what I found/read I need to do in the TE shader everything that was done in the vertex shader ...
0
votes
1answer
195 views

translate-scroll repeated 2d texture using opengl shader

I managed to implement an infinite 2d texture scrolling using the following shader. btw I'm using cocos2d-x 2.2.1. The vertex shader: attribute vec4 a_position; attribute vec2 a_texCoord; #ifdef ...
1
vote
1answer
138 views

glOrtho setting view

I am duplicating this thread from stackoverflow, please remove it if that is not allowed. I'm completely new in OpenGL. I have this problem: I have quite a complicated scene, and I am looking at it ...
0
votes
0answers
20 views

Sprite framework binding multiple textures

In an attempt to batch render as many quads (sprites) as possible, I'm instance rendering a single unit-sized quad and passing in a buffer of per-instance data that includes width/height, texture ...
0
votes
1answer
48 views

Backface culling without light leaking through

I want to be able to see through walls, so to do this I used planes for the walls, and enabled backface culling. However with shadow mapping I have a lot of light leaking through: I read that using ...
1
vote
1answer
64 views

Selection with region (when rendering with shaders and VAO)

I am currently render my geometry using "Modern OpenGL" approach (with shaders and buffers). I have already implemented picking of single primitives using glReadPixels. Now I am faced with problem how ...
0
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0answers
12 views

Jmonkey Translucent Render Bucket fails to model object last

So I have a weapon model that moves wherever the camera moves and the rotation of the weapon is the same as the rotation of the camera. Additionally I added the weapon to the Translucency Queue Bucket ...
0
votes
1answer
72 views

OpenGL not rendering full scene, it is a mystery [closed]

I am trying to draw a scene in the sort of style of mock vector graphics. I've helped on a 2D game before with GLSL, but I tried to keep a simple approach to this project since I'm working by myself, ...
1
vote
0answers
58 views

Shadow map shimmering, indexing outside the shadow map

I have tried to reduce shadow shimmering/flickering using technique described here: http://msdn.microsoft.com/en-us/library/windows/desktop/ee416324%28v=vs.85%29.aspx I works as I want and shimmering ...
1
vote
2answers
262 views

How are red dot/reflex/holographic sights implemented?

In first-person-shooters like Call of Duty, the hologram only appears when it is behind the glass portion of the sight. In OpenGL, would it be implemented by rendering the glass to the stencil buffer ...