Programming related to the visual representation of information on computer screens.

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24
votes
3answers
10k views

How can I make this style of 2D “glowing” graphics?

I'm comfortable with the basics of building a 2d sprite based game in XNA, where all my objects are simply .png images that I move around. What things do I need to learn next to be able to develop a ...
-2
votes
2answers
61 views

What's the difference between the representation of a line and that of a line segment?

What is the difference between a line and a line segment from the implementation point of view? To me, line segment means: class LineSegment2d { Point2d start, end; public: ...... } This ...
1
vote
1answer
98 views

Apply an special effect to an scene area

I have a 2D game where I have a second camera on my scene, that renders an upside down image of the scene, and distorts it, giving the effect of water reflection. I render this camera first, and on ...
0
votes
0answers
36 views

Texture artifacts depending on texture size

I get some strange artifacting with textures depending on their size. I run OpenGL 3.3 with an GTX 580 so it should definitely support non power of two textures. I've narrowed down the problem ...
0
votes
0answers
17 views

OpenGL textureGather and DirectX gather

These functions sample multiple RGBA pixels but return only a single component. OpenGL: https://www.opengl.org/sdk/docs/man/html/textureGather.xhtml DirectX: ...
5
votes
1answer
131 views

What is a lobe, in reference to lighting and graphics

I sometimes see references to lobes when talking about lighting, especially with specular lighting, but also with spherical harmonics which doesn't do specular. Can anyone explain what exactly a lobe ...
3
votes
2answers
419 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 ...
0
votes
0answers
35 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
0answers
45 views

Animations in games

I wonder how skeletal animations in games work. I am Writing my own Graphics Engine for "fun", and I have come across several problems with animations. Here is how I do it right now: 1: Load the ...
0
votes
1answer
65 views

Rescale pixel art scenery before rendering in SDL2

I looked at this page that mentions the SDL2_gfx library for rescaling SDL_Surfaces without the image getting blurry: SDL zooming/upscaling without images becoming blurry? I wanted to know if it was ...
4
votes
3answers
665 views

What Shading/Rendering techniques are being used in this image?

My previous question wasn't clear enough. From a rendering point of view what kind of techniques are used in this image as I would like to apply a similar style (I'm using OpenGL if that matters): ...
5
votes
2answers
172 views

Low quality bilinear sampling in WebGL/OpenGL/DirectX

I'm seeing low quality bilinear texture sampling in WebGL, OpenGL and Directx, and was wondering if anyone knew how to make it higher quality? The picture below should help show what I mean. The ...
0
votes
0answers
9 views

Creating VR Headset Video

So I have a video stream of known resolution and I have a VR headset via HDMI at a known resolution. Is there an existing library to create the slight fisheye and side-by-side layout for these ...
7
votes
1answer
87 views

Is quadrilinear texture sampling hardware supported?

If you have a volume texture with mipmaps, GL_LINEAR_MIPMAP_LINEAR texture sampling will perform quadrilinear texture sampling. Is that implemented in hardware like bilinear texture sampling is? Or ...
3
votes
2answers
526 views

How do I use graphics APIs to select the proper display device among multiple attached to a PC?

I have an LCD monitor display and Oculus Rift attached to my PC. I have an Nvidia 820M dedicated GPU. How does the GPU know to which display device it has to render (or to send rendered information)? ...
1
vote
2answers
84 views

Is it possible to run GLFW eventhough my graphic card(Nvidia) supports Direct3d API? [closed]

I have Nvidia 820M GPU installed in my windows 7 machine. In nvidia control panel it is showing it supports Direct3d API version 11. Am I able to run OpenGL applications(using GLUT,GLFW) on my machine ...
1
vote
0answers
41 views

Can you trilinear sample a non volume texture?

Let's say that i have a regular 2d texture (not a volume texture). Is it possible to do trilinear texture sampling of that texture even though it isn't a volume texture in opengl or directx? ...
5
votes
2answers
711 views

How can I tell a fragment shader to not write a particular pixel?

In a WebGL I'd like to send a screen space quad through that gets processed by a fragment shader, but have the fragment shader only write out a pixel under certain conditions (say... that it was ...
0
votes
1answer
65 views

Depth Stencil Buffer

In OpenGL, what is the difference between GL_DEPTH_COMPONENT and GL_DEPTH_STENCIL? I have looked around and have been unable to find a clear explanation. Information on their usage with GLSL would ...
2
votes
3answers
290 views

In a 2D top-down game, how can I create projectiles that have a height?

A 2D game called Deer Hunter has projectiles like this: Are the projectiles 2D or 3D models? How could I implement something similar?
0
votes
0answers
39 views

Is it reasonable to generate mipmaps on the color attachment of my framebuffer in realtime?

I'm looking into hdr tonemapping and so far all the equations I've found result in really, dulled results. One i haven't tried uses an average luminance of the image. The pdf I've been reading ...
1
vote
1answer
63 views

Question regarding irradiance

I know that the formula for irradiance at surface point p with normal n given a point light source at position l is: H = I(cos x) / ||l - p||^2 Where: x = angle between n and l-p I() = Intensity ...
1
vote
1answer
73 views

How to orthogonalize the “up” vector in a camera based on “eye”, “look” and “up” vectors?

Given a camera position defined as (eye, look, up), where "up" not quite at right angles to eye->look, how would I re-orthogonalize "up"? I've had a hunt around, but did not find anything, yet if I ...
57
votes
5answers
19k views

Which image format is more memory-efficient: PNG, JPEG, or GIF?

Which image format is more efficient to save memory? PNG, JPEG, or GIF?
0
votes
1answer
79 views

How to load in meshes efficiently into DirectX11

I wanted to know if there was a standard and efficient method to load meshes from a file into DirectX11. Currently, I'm loading .obj's by parsing them in and storing their information into a vertex ...
0
votes
1answer
55 views

DirectX11 Shader issue

I am currently having issues with HLSL shaders. I am trying to implement point lights but I am getting unusual data when debugging the shader in Visual Studio. I have read on several sites that say ...
0
votes
1answer
58 views

Creating procedural mesh with orientation

I am working on creating a procedural cylinder mesh with Unity C#. I have everything working but there is one thing I would like to implement in my existing code is to define a vector3 halfAxis which ...
0
votes
2answers
115 views

What's the correct way to move 2d sprites in opengl 2.1?

I'm getting into Opengl 2.1 and wanted to know how can I move 2d sprites. I already created my vbo and ibo, and the vertex data is already there. But, how can I move a sprite once it's already drawn? ...
1
vote
2answers
178 views

How to calculate alpha for n channels, so the sum equals 1 (100% coverage)?

Having "n" number of overlaying channels (bitmaps in the same place, layers etc.) how to calculate required alpha for each of them, so they "hide" background completely? Each layer can have equal ...
1
vote
1answer
137 views

Problem with 2D matrix transform og shapes

I have set myself onto the task of creating a class BaseObject, which represents a graphics object with an associated shape as the member variable shape, which is a pointer an object Polygon. I'll ...
55
votes
9answers
8k views

2D graphics - why use spritesheets?

I have seen many examples of how to render sprites from a spritesheet but I havent grasped why it is the most common way of dealing with sprites in 2d games. I have started out with 2d sprite ...
1
vote
1answer
152 views

How does an energy-conservative Blinn-Phong-Fresnel model work?

What is a plausible, basic equation/pseudo-code for energy-conservative Blinn-Phong shading, including Fresnel with a coloured light-source? The net gives so many alternatives that it's hard to ...
2
votes
1answer
157 views

What are some ways of making a game engine centered around the idea of drawing vector lines and polygons only? [closed]

I've always loved the look of games that just use simple lines and polygons for graphics. Rez is one of my favorite games, visually. I'm a programmer and designer first and foremost, and I'm horrible ...
0
votes
1answer
76 views

How do I draw long tiled paths in 2D? (Eye of the Beholder style)

I'm using artwork from the following page: http://opengameart.org/content/first-person-dungeon-crawl-art-pack As you can see with the first artwork, the grass field is long. The floor also goes into ...
1
vote
0answers
54 views

How can I approximate an “opening fan”-transformation?

Is there a way to—with matrices—transform something as if opening the image on a Japanese folding fan? Image from Wikimedia Commons. I'm at a loss of what to call it, so pointers towards avenues of ...
3
votes
2answers
81 views

In XNA 4, how can I access SpriteBatch's transformMatrix in my shader?

I would like to use a custom effect with a regular XNA SpriteBatch. I have a 2D camera which computes a transform matrix, so I need my shader to take this into account. I have put a world matrix ...
1
vote
0answers
54 views

Why does XNA create two GraphicsDeviceManager services?

While working with XNA today, I looked at the debugger information for Game.Services to retrieve the GraphicsDeviceManager so that a component could utilize it. Instead, I found two different objects: ...
-1
votes
1answer
51 views

How would I go about merging two models together in-game to create a new model? [closed]

Let's say I have two models: model 1 is hilt and model 2 is blade. How would I merge these to models together to create a sword?
0
votes
0answers
8 views

Fill color in moving object without flickering [duplicate]

Here is my code in which moon is moving around earth but now i want to fill moon and earth with color and also want to remove flickering in the moon while moving. Please help me, i will be very ...
35
votes
2answers
7k views

Why are normal maps predominantly blue?

Why normal maps are predominantly blue instead of a random color? I guess normal vectors of a 3D object can point in every direction, like: (1.0, 0.1, 0.5), (0.1, -0.5, 0.3), (-0.51, 0.46, -1.0) ... ...
2
votes
0answers
59 views

Tangents face the same direction on opposite sides of mesh

I have noticed that the tangent vectors that I am calculating are not always facing the correct direction. The tangents on the left and right of the mesh both face the same direction. Here is a ...
-1
votes
1answer
144 views

How to move object along circumference of another object? [closed]

I have following piece of code, now i want to move the "moon" object in the orbit around "earth". please help!! #include <stdio.h> #include <conio.h> #include <graphics.h> #include ...
3
votes
1answer
451 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, ...
3
votes
1answer
412 views

Mixing Perspective and Orthographic Projections?

I'm going to start with some background, so jump to my question at the bottom for the TLDR version. Problem: In a Japanese 4gamer article (english translation via Chev on Polycount) explaining some ...
0
votes
0answers
105 views

How to get drawing offsets for an isometric camera

I do have some semi-working code, but I'm really stuck on getting everything to align to the screen properly. Here's my current, broken solution in Javascript: //ts = tile size (i.e. 64), th = ts/2, ...
1
vote
1answer
77 views

Quick sprite contouring solutions?

I want to be able to quickly outline sprites(mainly with black, but other colours too) without doing it manually, as pictured. What would be a good program/solution to do so? Edit: I don't want it ...
5
votes
1answer
199 views

Why bother with a separate normal matrix, if there is never non-uniform scaling on the view matrix?

I am updating one of my shaders to a version of OpenGL/GLSL that doesn't automatically provide gl_NormalMatrix (for educational purposes; I'm not ripping out working code for the sake of it). ...
1
vote
1answer
245 views

how much memory does Adreno 320 GPU provide? [closed]

I wanted to know how much memory does Adreno 320 GPU provide ? I am using Nexus 4. I Googled about it and not able to find any details about it. Can anyone provide the details?
9
votes
1answer
436 views

In OpenGL, what is “zero state” rendering?

Recently at a job interview, I mentioned that I taught myself modern OpenGL and rendering with vertex buffer objects because my university only taught the fixed function pipeline with immediate mode ...
22
votes
4answers
10k views

How can I draw outlines around 3D models?

How can I draw outlines around 3D models? I'm referring to something like the effects in a recent Pokemon game, which appear to have a single-pixel outline around them: