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
1k views

Creating a 3D text mesh from a 2D glyph

I have thought of three steps for doing this: Acquire the vertex coordinates which will represent the glyph's form Extrude them Render Can you suggest a better method? Can you give me an insight ...
1
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1answer
659 views

How do I build Assimp with MinGW?

How can I build Assimp with cMake and MinGW? I tried, but I don't get a functioning library... Details of my attempt: I am trying to build the Open Asset Import Library (Assimp) but I have been ...
7
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6answers
2k views

Correct level of abstraction for a 3d rendering component?

I've seen lots of questions around this area but not this exact question so apologies if this is a duplicate. I'm making a small 3d game. Well to be honest, it's just a little hobby project and ...
1
vote
1answer
649 views

Geometry shader and triangle adjacency

I'm currently trying to change my project to use GL_TRIANGLE_ADJACENCY instead of GL_TRIANGLES. Following this question, I have managed to construct my index buffer fine, but when it comes to the ...
2
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1answer
29 views

Underwater Shader Animation Help

I found an underwater (distort) effect and I got it to work but somehow I cannot make it animate given the offset here: Fragment Shader code: uniform sampler2D fbo_texture; uniform float offset; ...
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1answer
312 views

How to compute matrix transform local/world on OpenGL

I'm developing an OpenGL program where each object / entity contains m_WorldPosition, m_WorldOrientation, m_WorldScale and m_WorldTransform (Vector3, Quaternion, Vector3 and Matrix4f). The problem is ...
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1answer
16 views

Passing data into a vertex shader for perspective divide

In OpenGL and GLSL, I am just learning about perspective projection and the vertex shader. However, I am a little confused about what data actually needs to be passed to the vertex shader, and what ...
4
votes
1answer
160 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 ...
5
votes
1answer
396 views

Multithreaded Game Loop

I'm trying to implement a multithreaded game loop. I already did that but had to use a few locks for that, which ruined the performance. After researching a bit I came up with this idea: Instead of ...
0
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1answer
101 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 ...
1
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2answers
263 views

Tiled Rendering - Projection matrix

I'm trying to figure out how to perform tiled rendering of my 3d scene (OpenGL). The motivation is to cut the scene up into several textures, combining them into a single image for saving at a very ...
0
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2answers
35 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
48 views

Octree Frustrum Culling

times came when i had to implement some culling into my engine. I started by reading some stuff and so far so good. I managed to create an octree which can effectivly divide my geometry's vertices ...
0
votes
1answer
205 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(); ...
0
votes
1answer
101 views

Small text is very light / faint with FreeType and OpenGL

I'm able to render large text with FreeType just fine: But when I want to render small text (and the only parameter that changes is the font size), the quality is much poorer: As you can see, ...
0
votes
1answer
479 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 ...
0
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1answer
95 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 ...
1
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0answers
18 views

Vbo 3d triangle opengl w/ LWJGL

So i am using lwjgl, took me about 4 hours of hard work to achieve triangle rendering and vbos, now i want to render a triangle in 3d space. I know you have to use projection matrices. But when i have ...
5
votes
4answers
4k views

Can't understand these UV texture coordinates (range is NOT 0.0 to 1.0)

I am trying to draw a simple 3D object generated by Google SketchUp 8 Pro onto my WebGL app, the model is a simple cylinder. I opened the exported file and copied the vertices positions, indices, ...
0
votes
1answer
16 views

Using glm to rotate the modelview matrix based on the cursor position

I am rendering a 3D model of an object, and I want the user to be able to rotate around that object by dragging the mouse. To do this, I want to use the cursor position to continually update the ...
0
votes
1answer
114 views

How to Load a Level for use with the Bullet Physics Library

I am trying to use a level in .obj format loaded with Assimp to generate a btBvhTriangleMeshShape to use with the Bullet physics library. I can successfully load btConvexHullShapes as well ...
0
votes
1answer
99 views

How to clip or mask entity in adnroid/andengine?

I want to implement masking with sprite in Andengine. I want same functionality as in ios class called SKCropNode which works like an masking node! Is there any workaround like this in ...
0
votes
0answers
22 views

OpenGL Black rectangle in rendering texture

I create textures (for example, I just fill the texture color), and render their. But, for some reason, to the upper edge added black rectangle. Screenshot: var Textures: array of GLuint; ...
2
votes
0answers
37 views

equirectangular panorama rendering?

I want to render my scenes as equirectangular panorama frames. I can get the angular fisheye which is what I actually need by applying the rendered frame as a texture to a correctly UV mapped circle. ...
2
votes
0answers
27 views

OpenGL Depth Cubemap with Geometry Shader Not Rendering Correctly

I was having some trouble with cubemaps in OpenGL, and was hoping to get some help. I've been following a tutorial about point light shadow mapping using cubemaps, where a geometry shader is used to ...
0
votes
0answers
80 views

How do I extract the right information from my projection matrix for frustum culling?

I've tried several different tutorials for Frustum culling, however I cannot understand them. Here's my function that sets up my projection matrix (someone else helped me with this, but I don't know ...
23
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5answers
16k views

How to avoid texture bleeding in a texture atlas?

In my game there is a Minecraft-like terrain made out of cubes. I generate a vertex buffer from the voxel data and use a texture atlas for looks of different blocks: The problem is that the texture ...
0
votes
1answer
49 views

How to wrap textures inside shader GLSL

I'm trying out GLSL and one of the problems I'm facing is wrapping a random texture sampler in the shader. Searching for answers on the web first, this leads me to using these commands: ...
1
vote
1answer
52 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 ...
0
votes
0answers
18 views

Trouble texturing isometric tiles with tilesheet: OpenGL

I don't know if I am just... not seeing something here. I have been working on this for quite some time trying to get it functioning. I have used sprite sheets and texture coordinates before - so I am ...
1
vote
1answer
30 views

How to correctly specify the offset in a call to glVertexAttribPointer()?

I'm trying to draw a simple triangle using the following vertices: std::vector<VertexFormat> vertices; vertices.push_back(VertexFormat(glm::vec3(0.25, -0.25, 0.0), glm::vec4(1, 0, 0, 1))); ...
1
vote
1answer
52 views

Greedy Mesh generation for a voxel-based game

EDIT: I have already found my problem and fixed it (but I cant accept my own answer for another 2 days) I'm currently making a 3D voxel-based game and now that I have started optimising some aspects ...
0
votes
1answer
41 views

Beginning on animations

I am clueless with regards to animations. I have a simple rendering engine that renders models, sprites, skyboxes and whatnot; but everything is simply static with no animations whatsoever. With my ...
1
vote
1answer
205 views

SDL & OpenGL - Artifacts when multisampling

Im trying to render a model with anialiasing using OpenGL and SDL, but when I do I get strange artifacts. When I render with antialiasing disabled everything looks fine. When antialiasing is ...
1
vote
0answers
33 views

Set Render Target usage

I am using Unity and I have some difficulties about understanding the way Set Render Target works and how it can behave with the shaders. Is it possible to render a shader pass in multiple render ...
1
vote
1answer
874 views

How can I prevent the viewport from stretching/distorting?

Basically, I want to know how I can remove distortion or stretching of the rendered image when the viewport/window size changes. The following images exemplify the distortion/stretching I'm talking ...
3
votes
2answers
150 views

How do I pick tiles from an isometric map with slopes?

I'm looking for a way to convert mouse/screen coordinates to isometric map coordinates, with the addition that the world has slopes and cliffs, and I have to be able to tell which quadrant of the tile ...
0
votes
2answers
90 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 ...
0
votes
0answers
7 views

Using AWT with LWJGL on OS X

The VM argument -XstartOnFirstThread is required for LWJGL to work on OS X. Anything in the java.awt package freezes the JVM when used with the VM argument -XstartOnFirstThread. E.g. ...
3
votes
1answer
340 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 ...
1
vote
3answers
47 views

OpenGL, GLSL, Modify Background Fill via Fragment Shader

I have noticed that fragments rendered by the glClearColor() method do not pass through shaders. However, I'd like to modify these fragments using my fragment shader. Is there any way of forcing them ...
1
vote
0answers
11 views

OpenGL (lwjgl) Frame Buffer Object GL_COLOR_ATTACHMENT Not Being Written To

I am currently developing a deferred renderer for my game engine and I have to output multiple textures from my shader to my GBuffer. I have been struggling with getting multiple outputs from the ...
4
votes
5answers
298 views

How can I render “two-sided” clouds like in Minecraft?

The clouds in Minecraft are semi-transparent and are rendered on both sides. If you fly into the cloud you can see inside of the cloud. If I render clouds the inside faces would be visible on the ...
7
votes
2answers
694 views

How can I debug _why_ glDrawArrays is very slow?

I'm working on a game that uses CEGUI and Ogre. Recently, we've discovered that some of our customers with GeForce4 MX 4000's, performance is terrible. After a night spent debugging, I've tracked ...
0
votes
0answers
12 views

Using gl3w and Win32 api, without glut

I'm still a beginner, the example on skaslev's site require us to use glut as an interface to create a window. For some reason, I'm required to create a window purely with Win32 api, but I am not ...
0
votes
0answers
52 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: ...
1
vote
1answer
66 views

Android OpenGL EGL context lost

I'm developing simple Android game in OpenGL ES 2.0 and the development stage is getting closer to publishing game on play store, but I'm still unsure about EGL context behaviour on different devices. ...
0
votes
0answers
61 views

How to calculate spherical harmonic coefficients for indirect diffuse?

After reading the article "An Efficient Representation for Irradiance Environment Maps", I'm a bit confused as how to calculate the spherical harmonic coefficients. I'd like to generate these ...
0
votes
1answer
202 views

DirectX11 Equivalent of OpenGL code

I am currently porting parts of my engine over to D3D11 from OpenGL and was trying to figure out how I would accomplish the following blending functions in D3D11. glEnable(GL_BLEND); ...
0
votes
2answers
125 views

GL_SPOT_CUTOFF not working properly

I'm new to OpenGL. I'm studying OpenGL 2.1 and I'm trying to make a little program to test the GL_SPOT_CUTOFF property, but when I set a value between 0.0-90.0, the light doesn't work and everything ...