Tagged Questions
3
votes
2answers
121 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
0answers
43 views
Default material properties and assimp
I am using assimp to import 3d models and I have a question on the default properties on materials, more specifically on the diffuse, ambient and specular material colors.
In assimp, if the model ...
-4
votes
1answer
92 views
What's the complexity, given current technology, of writing a decent scene renderer in OpenGL? [closed]
What's the complexity, given current technology, of writing a scene renderer that produces reasonably high-quality output in OpenGL?
I'm definitely not asking about writing a full games engine - ...
0
votes
1answer
123 views
Ogre3d or OpenGl or other [closed]
I want to learn Graphics for games or use a game engine. I don't know whether to use ogre3d, I know its a rendering engine however android isn't really supported, Boost is used for multithreaded when ...
0
votes
1answer
78 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
93 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
107 views
graphic effects of Android game “Achtung” [closed]
I would be very gratefull if someone can give me a hint how the graphic effects of this android game ( http://www.isignz.nl/achtung ) works. Let us let this "pixie dust"-stuff aside for the moment; I ...
0
votes
0answers
255 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
206 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
81 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
210 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):
...
22
votes
10answers
2k 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
231 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
0answers
80 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 ...
15
votes
2answers
801 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?
5
votes
3answers
601 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
276 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 ...
1
vote
1answer
697 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 ...
8
votes
2answers
2k 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
112 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
386 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
228 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
297 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
296 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
252 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
479 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 ...
4
votes
1answer
856 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
252 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
122 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
1k 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
393 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
762 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 ...
2
votes
1answer
592 views
OpenGL ES drop shadows for 2D sprites
I've got a an OpenGL scene rendered with a bunch of sprites, and I'd like to automagically add drop shadows to all of them. Here's a picture showing what I mean:
The scene uses orthographic ...
-1
votes
1answer
1k views
C#: What graphics library would be best to use? [closed]
I am making my first game with 3D graphics, and I wanted to decide on a graphics library before I do any graphics work. I am using C# VS Express 2010. I have seen suggestions for XNA, Tao, and just ...
4
votes
3answers
3k views
Should I use Game Engines to learn to make 3D games?
HI i am a software engineering student in his second-last year.
I am proficient with C,C++,C# and java programming languages, and being a student of engineering I have studied calculus, vectors etc ...
1
vote
1answer
415 views
A comparison of graphics libraries and their respective programming languages [closed]
A comparison of graphics libraries and their respective programming languages. A.K.A. "Which do I pick? With a twist."
I'm a long time professional programmer who never gave up on programming as a ...
4
votes
1answer
757 views
How do engines like Unreal relate to OpenGL or D3D?
Well I'm completely completely new to computer graphics and even more to game development. I am searching info and all that stuff to have the basics quickly. But there's a big question mark in my ...
5
votes
3answers
946 views
What features does D3D have that OpenGL does not (and vice versa)?
Are there any feature comparisons on Direct3D 11 and the newest OpenGL versions?
Well, simply put, Direct3D 11 introduced three main features (taken from Wikipedia):
Tessellation
Multithreaded ...
5
votes
2answers
746 views
Getting the number of fragments which passed the depth test
In "modern" environments, the "NV Occlusion Query" extension provides a method to get the number of fragments which passed the depth test. However, on the iPad / iPhone using OpenGL ES, the extension ...
9
votes
3answers
2k views
Animation in OpenGL using 3D Models
I have created a model in Blender. Now i want to read that 3D model in my c++ program. I figured that a model can be exported to various file formats e.g. .obj, .3ds or COLLADA and then can be read in ...
2
votes
1answer
305 views
Why am I having these weird framerate issues with OpenGL on Windows?
I'm using OpenGL on windows (have been for a while now), and I've come across a strange issue.
Once every so often, the rate at which frames are presented on the screen drops to roughly 10 fps. ...
7
votes
3answers
447 views
I would like to know how an OpenGL driver will be implemented to learn opengl internals?
I'm learning OpenGL and really like to know how the interaction with the Graphics card will be.
I feel understanding how it was implemented in the Graphics driver, will let me know complete internals ...
5
votes
3answers
1k views
Draw contour around object in Opengl
I need to draw contour around 2d objects in 3d space. I tried drawing lines around object(+points to fill the gap), but due to line width, some part of it(~50%) was covering object. I tried to use ...
1
vote
2answers
256 views
Different types of memories which a graphics card has
I've been googling this around and yet nothing showed up but some articles from middle ages which were talking about Gforce mx and ... . My question is just this: what are the different memories in a ...
3
votes
1answer
485 views
Meaning of knots when drawing a NURBS curve?
I'm using gluNurbsCurve to draw some curves with some control points. I've got the basic setup as described in the red book working correctly and I'm trying to expand on it.
This sample looks like ...
1
vote
1answer
2k views
OpenGL 3D Camera
And here I am again, looking for help with my OpenGL camera once again. This is starting to get embarrassing. Anyway, here's the deal: I think my OpenGL First Person free roaming camera is starting ...
3
votes
0answers
267 views
How to depict a ramp for a top down 2D perspective? [closed]
I'm writing an android app and am looking for some ideas on how to render a ramp (or possibly speed bump) that will launch an object into the air. Probably something with gradients. This is for a top ...
3
votes
7answers
2k views
openGL book recommendation
I wanna start learning OpenGL especially for android game programming but I would eventually want to be able to use this knowledge for windows\linux as well.
I'm having difficulty choosing between ...
2
votes
2answers
215 views
Is it ok to use NPOT textures with OpenGL in this situation?
I drew some icons to use on orthographic projection and instead of loading each icon file individually as a texture I thought of putting them all together in one single file. Now I have a file 72x36 ...
3
votes
1answer
244 views
Looking for literature about graphics pipeline optimization
I am looking for some books, articles or tutorials about graphics architecture and graphics pipeline optimizations. It shouldn't be too old (2008 or newer) - the newer, the better.
I have found ...
