0
votes
2answers
137 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 ...
0
votes
2answers
52 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. ...
1
vote
1answer
53 views

DirectX Bullet Tracer Effect

I'm wondering if anyone knows some common and efficient ways to do a fast tracer for an instant bullet. I've seen people speak on forums of using primitive lines with DirectX, but I doubt this ...
3
votes
2answers
191 views

Is there any reason why there isn't a cross-platform implementation of DirectX?

Similar to how Mono can compile C# to various platforms, why isn't there an API that conforms to DirectX's specifications but can produce binaries for all platforms? I understand that there is OpenGL ...
0
votes
0answers
33 views

Calculate parameters for orthographic matrix for directional shadow mapping

I am struggling with how I can fit my scene in an orthographic projection, based on what is visible by the camera. All tutorials so far explain almost everything in perfect detail, and then for the ...
0
votes
0answers
44 views

Shadow Mapping: How to calculate Axis Aligned Bounding Box?

I am trying to implement Shadow Mapping, which is actually working with an AABB that always covers my entire scene, but (obviously) it gives very blocky graphics. So I figured I need to calculate a ...
0
votes
0answers
30 views

Rotating an object towards a point in OpenGL C++ [duplicate]

I calculate the matrix like this: modelMatrix = glm::translate<float>(position) * glm::rotate<float>(orientation.x, glm::vec3(1, 0, 0)) * glm::rotate<float>(orientation.y, ...
1
vote
1answer
120 views

How to enable geometry shader in OpenGL 4.2?

I'm porting my Direct3D-based engine to OpenGL and I'm using geometry shaders for rendering text characters (basically, textured billboards). D3D version works fine, but in OpenGL mode it gives only ...
1
vote
3answers
177 views

How do I efficiently use 16 bit texture coordinates?

While loading a model I get a big array of 32 bit floating point texture coordinates. I just upload that to a single vertex buffer (along with other data, such as vertices, normals, etc.) and use it ...
3
votes
1answer
204 views

Solving banding with additive blended particles

I needed to implement particles for my 2D game, written in C++ with OpenGL for graphics, so I went ahead and created a nice geometry container to batch particles together and then implemented the ...
0
votes
1answer
33 views

Versions of GL and its device that don't display or required powers of 2 for the sprites

From this question aside from identifying possibilities of displaying images that don't needed to require powers of 2, what are the versions of GL that can actually display images even if don't needed ...
3
votes
2answers
225 views

When is the Z coordinate normalized in GLSL?

I thought that whenever you transform an object to world space, then view space and finally screen space, the last matrix you apply(the projection matrix) normalizes the z values between 0 and 1. ...
2
votes
1answer
189 views

How does the fragment shader get data from the vertex shader?

How can any interactions between these two shaders work? I mean the vertex shader sends a vertex's color to the fragment shader, but that's only one fragment, what about all the other ones between the ...
1
vote
1answer
129 views

What is the difference between shader uniforms and attributes in OpenGL?

I don't fully understand the differences between uniforms and attributes. To be honest, I probably haven't even used attributes. Can uniforms change for each vertex? I mean to calculate the vertex's ...
2
votes
1answer
142 views

Are ambient, diffuse and specular light or material properties?

Are ambient, diffuse and specular properties of light or material? I am doing ray casting in OpenGL, I've managed to create lit sphere using formula I = L Ka + L Kd (n . l) + L Ks (r . v)^n but I ...
1
vote
1answer
105 views

What is w componet [duplicate]

What is the W component on graphics programming. I read a blog about opengl that says that w must be equal to either 0 or 1 here. But the book I am currently reading has put w component to more than 1 ...
3
votes
1answer
160 views

How to Construct a Perspective Projection With 4 Vanishing Points

Is it possible to construct a projection matrix which will create a perspective with four (or more) vanishing points? This question have an OpenGL tag, but general insights are welcomed as well.
0
votes
1answer
72 views

Displaying normals of a geometry

I have a rectangle which is created by 2 triangles and it is in x-z plane, and i have object on it. Now, the normals of two triangles (face normals) are y axis i.e. (0,1,0). I want to display normals ...
0
votes
1answer
512 views

rotating 3D object around the center

I have object moving from A to B on x-axis and there is no translation of object apart from it. Now, while moving, i want to rotate it around y-axis and the motion should change accordingly, i mean if ...
1
vote
1answer
99 views

How to render models using a personalized projection matrix?

I'm creating a game with a great sprite demand. Out team is considering automatizing the sprite generation using 3D models. The problem is we have a very particular ortographic projection: We have ...
1
vote
0answers
221 views

OpenGL: Attempt to allocate a texture too big for the current hardware

I'm getting the following error: java.io.IOException: Attempt to allocate a texture to big for the current hardware at ...
1
vote
1answer
104 views

How can I find the location of OpenGL object after rotation?

I have a rotating object, a cube, which I rotate in OpenGL as follows: gl.glPushMatrix(); gl.glTranslatef(400.0f, 300.0f, 1300.0f); gl.glRotatef(m_x, 4.0f, 0.0f, 0.0f); gl.glRotatef(m_y, 0.0f, 4.0f, ...
3
votes
2answers
284 views

Using a programmable pipeline in a game engine

As a learning experience, I'm developing my own 3D game engine using OpenGL. I'm a little confused as to how to implement my rendering engine such that it uses a programmable pipeline while still ...
0
votes
1answer
509 views

Reinhard tone mapping and color space [closed]

I found two ways of doing tone mapping (first, second): //Ld - this part of the code is the same for both versions float lum = dot(rgb, vec3(0.2126f, 0.7152f, 0.0722f)); float L = (scale / ...
2
votes
1answer
244 views

RGB to xyY color space conversion and luminance

The luminance calculated by following GLSL functions (fragment shaders - tonemap) has different value: float GetLuminance (vec3 rgb) { return (0.2126 * rgb.x) + (0.7152 * rgb.y) + (0.0722 * ...
0
votes
0answers
793 views

How to do collision detection in 3D using bounding boxes?

I am using c++ in visual studio 2010 with opengl. I am trying to make a programme that has 2 boxes that are able to be stacked on top of each other but I am having some trouble with the collision ...
-5
votes
3answers
297 views

in the shadow of a sphere [duplicate]

(Related, but somewhat different, to my previous question) How can I determine in a fragment shader if a fragment is in the shadow of a sphere? That is, if it is occluded by the sphere and is past ...
0
votes
1answer
180 views

Devices or Smartphones That Can Run and Displayed Images Properly While Power of 2 Code is Disabled

Before making game apps, I want to have any certain smartphone device brands that runs on OpenGL. I have to make a code for images that doesn't need to required power of 2 images so that I can resize ...
5
votes
1answer
368 views

What are the rest of the blending functions used for?

In general, I know of five ways to make use of blending functions (these are for OpenGL, but replace glBlendFunc() with SetRenderState(D3DRS_SRCBLEND) and SetRenderState(D3DRS_DESTBLEND) for DirectX): ...
29
votes
10answers
3k views

What makes a game look “good”?

I am working on a 3D space game using OpenGL and C++ and I am planning to focus on giving the game modern, eye-catching graphics, but the more I think of it the more I realise I don't really know what ...
5
votes
1answer
715 views

What is actually drawn when glDrawArrays and glDrawElements are called?

In my journey out of immediate mode I've come across a snag that I haven't been able to find a decent answer for in any tutorial or API, namely: Which data structures are actually invoked when I make ...
0
votes
1answer
166 views

Opengl binding shaders vs binding buffers performance

Quick question for an opengl guru, I'm in the process of building a render queue and can either reduce the number of shader binding or the number of vertex buffer binding. I just want to know which ...
17
votes
3answers
2k views

What's the difference between mesh and a model?

Which one is created first? For example if a team worked on a graphical asset of a car, what would be a model and what would be a mesh of the car?
6
votes
3answers
861 views

Understanding how to create/use textures for games when limited by power of two sizes

I have some questions about the creating graphics for a game. As an example. I want to create a motorbike. (1pixel = 1centimeter) So my motorbike will have 200 width and 150 height. (200x150) But the ...
5
votes
1answer
414 views

How to flip a BC6/BC7 texture?

I have some code to load DDS image files into OpenGL textures, and I'd like to extend it to support the BC6 and BC7 compressed formats introduced in D3D11. Since DirectX and OpenGL disagree about ...
3
votes
1answer
1k views

Correct use of VAO's in OpenGL ES2 for iOS?

I'm migrating to OpenGL ES2 for one of my iOS projects, and I'm having trouble to get any geometry to render successfully. Here's where I'm setting up the VAO rendering: void bindVAO(int ...
10
votes
2answers
4k views

OpenGL: VBO or glBegin() + glEnd()?

I recently was given this link to a tutorial site from someone who I gave the original OGL Redbook to. The third header down says distinctly to forget glBegin() & glEnd() as the typical render ...
0
votes
1answer
119 views

Split vector vs matrix notation for transformation

Some rendering engines like Ogre prefer to use a individual vector based notation for transformations like the following Split vector notation: Net Transformation is represented by Scale vector = sx, ...
3
votes
2answers
616 views

OpenGL behaviour depending on the graphics card?

This is something that never happened to me before. I have an OpenGL code that uses GLSL shaders to texture a 3D model. The code involves a lot of GPU texture processing, blending, etc... I wanted to ...
0
votes
0answers
309 views

Camera rotation flicker in OpenGL ES 2.0

I implemented an orbit camera in my own OpenGL ES 2.0 application. I was getting extensive amount of flicker while rotating the camera using the mouse. When I added the line eglSwapInterval( ..., ...
2
votes
2answers
552 views

Can frequent state changes decrease rendering performance?

Can frequent texture and shader binding decrease rendering performance? "Frequent" binding example: for object for material in object render part of object using that material "Low count" ...
0
votes
1answer
469 views

3DS Max exporting too many vertexes for model

I have a sample model of a cube and a buddha downloaded from internet in 3ds format which I can load correctly into my program and view them without problem, but wanted to try and create my own model. ...
2
votes
1answer
364 views

Fog with Blend in OpenGL

I want to add fog in my scene which contain transparent textures made by Blend , when i enable the fog the transparent textures appear white From a distance but when i disable it the textures ...
0
votes
1answer
635 views

OpenGL : Suggestion on handling collision detection and vertex data?

I was thinking how to do collision detection in my OpenGL application and came to conclusion that I should keep two copies of my geometry data. 1)First copy : Only for OpenGL rendering purposes.This ...
5
votes
1answer
2k views

GLSL default shaders

I've been arming my engine with error checking code. I'll try to describe this situation to my best abilities. Whenever i load a shader and there's an error (file doesn't exist, compilation error, ...
0
votes
2answers
665 views

GLSL shader compilation

When i'm compiling a shader does it have to be complete? Can i use glCompileShader on a shader without a main() function? The OpenGL reference documentation has a nice writeup on program linking ...
0
votes
1answer
151 views

handling buffers in OpenGL

I'm reading through the OpenGL docummentation for version 3.3 core. I'm having issues understanding proper buffer deletion. ATM i have an object that loads itself into OpenGL memory in the ...
7
votes
2answers
2k views

Fastest way to draw small particles in opengl?

Quick question : Which is the fastest method to render a large array of 4x4/8x8 particles in opengl ? Currently i spend 2triangles for each one but i think that its slow so i would really like to know ...
5
votes
1answer
613 views

Difference between the terms Material & Effect

I'm making an effect system right now (I think, because it may be a material system... or both!). The effects system follows the common (e.g. COLLADA, DirectX) effect framework abstraction of Effects ...
1
vote
2answers
1k views

Back-face culling in 2d openGL game

I have a 2d game I've made using openGL ES. The game contains a large quad that fills the entire screen (as a background image) and many smaller quads that make up a number of balls that bounce across ...