2
votes
1answer
181 views

Day and Night Cycles and Skybox Blending

I've been working on adding day/night cycles and random weather to my project using the Neoaxis engine. The day/night cycles itself is pretty simple, just rotating the "sun" light around the Y axis. ...
6
votes
1answer
137 views

Reducing Spherical Harmonic Ringing

I've generated some 2nd order SH light-probes from cube-maps in my scene and I was surprised how strong artifacts are around the back of the dominant lights. I switched to a Lambert source plus ...
5
votes
1answer
204 views

Are there multiple valid definitions for what translate, rotate and scale do?

Are there multiple valid definitions for what translate, rotate and scale do to the 4x4 matrix? I bring up this question, because I have a simple webgl program that draws a square and does a few ...
3
votes
1answer
159 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
0answers
29 views

Is there a transformation or set of transformations that can approximate a “radial scale”?

Is there a way to, with matrices, scale something as if someone were opening a Japanese fan? I'm at a loss of what to call it, so pointers towards avenues of research would be greatly appreciated. If ...
4
votes
1answer
433 views

GGX specular BRDF is way over 1!

Now, the classic Torrance derivation for roughened surfaces which Cook took into vectorized form yields the familiar parametrization of a specular BRDF where we have the NDF which decides how much ...
3
votes
1answer
88 views

Symmetry preserving path simplification

I'm using the Douglas peucker (DP) algorithm to simplify some (2d) closed paths forming a shape. This works pretty good, but not so much for closed paths that have some symmetry. Take for example a ...
2
votes
0answers
134 views

Quaternion to direction vector - flipping

I've kinda solved this myself by adapting the Camera::setDirection code from OGRE to work for my need: Now I have the following code: Vector3 boneDir = getBoneWorldOrientation(mEntity, mHips) * ...
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 * ...
1
vote
1answer
111 views

Movement constrained to the faces of a cube

The basic setup I'm working with is a cube rendered in-Engine (Panda3d, although I only am looking for a generalized solution) as well as a 2d square on one face of the cube. The eventual outcome I'm ...
-2
votes
1answer
193 views

Move projectile in direction the gun is facing [duplicate]

Possible Duplicate: Move sprite in the direction it is facing? I am attempting to have a projectile follow the direction a gun is facing. When using the following code I am unable to make ...
2
votes
1answer
1k views

global transform to local transform?

If an object is attached to another one and you need to set its position, rotation and scale in global space, what do you do to get the local versions of these values, knowing the same values for the ...
2
votes
1answer
359 views

Detect mouse click on a bezier curve's neighborhood

I'm developing a game in HTML5 and JavaScript using Canvas API for drawing graphics. I want to detect if the user has clicked on a bezier curve which has the line width of 20 pixels (something like ...
3
votes
0answers
188 views

Web sites with famous game information? [closed]

Is there any website containing informations related with some famous game? For information I mean how to calculate damage in a rpg for example, or how they've set camera and other tips like this! ...
0
votes
2answers
401 views

3D Vector “End Point” Calculation for procedural Vector Graphics

Alright, So I need some help with some Vector Math. I've developing some game Engines that have Procedural Fractal Generation for Some Graphics, such as using Lindenmayer Systems for generating Trees ...
1
vote
3answers
766 views

How do you blend multiple colors in HSV (polar) color-space?

In RGB color space, you can do a weighted multiple-color blend by just doing: Start with R = G = B = 0. Then we perform a blend at index i using a set of colors C, and a set of normalized weights w ...
1
vote
1answer
497 views

Problems with 3D rotation when creating a 3D skeleton

I am writing a simple BVH parser in C# using the XNA framework. At the moment I have managed to parse in all the data and my goal is to find out the global coordinates of all the joints in the ...
14
votes
5answers
3k views

Quick 2D sight area calculation algorithm?

I have a matrix of tiles, on some of that tiles there are objects. I want to calculate which tiles are visible to player, and which are not, and I need to do it quite efficiently (so it would compute ...
2
votes
2answers
810 views

How can I transform a point from world space to object space?

If I have an object space described by transformation matrix that should be applied to object to transform it to world space, what I have to do to transform point (world space) to that object space. ...
14
votes
3answers
1k views

What does the graphics card do with the fourth element of a vector as the final position?

From this question it appears you would want a four-element position vector, as it is simpler to modify its position with matrix multiplication. On its own this would imply the fourth element should ...
2
votes
3answers
511 views

Find new position of rotated by 10 degrees line

I have a line that goes to x (x1) of 300, and then I rotate the line by -10 degrees. How can I get the new x (x0) of the rotated line? Here's a picture to show what I mean: Are there any books ...
1
vote
1answer
464 views

How to form a concave shape out of convex shapes? [closed]

I'm trying to get around the rule of only being able to form convex shapes in the SFML C++ library. To do this I'm planning on testing given vertices, and if concave, splitting the vertices ...
0
votes
2answers
1k views

my SFML sprite Move() function: FeedBack?

Hey so i'm making a pong game with SFML and in the process made a function that takes a Time, Speed, Angle of movement, buffer for the movement on the X axis, and buffer for the movement on the Y ...
6
votes
3answers
1k views

top down game - checking, drawing enemy's line of sight area with obstacles

Examples of what i'm going to need: I'm using cocos2d to draw a CCTMXTiledMap, on those tiles i'll have to draw the LOS cone. How would i test if the player is within that cone, taking obstacles ...
3
votes
2answers
7k views

Rotate vector by matrix?

If I have a Vector, say (1,1), how can I rotate it around the origin (0,0)? I'm working in XNA if that helps.
14
votes
2answers
2k views

Bezier curve arc length

How can I find the distance traveled by a Bezier curve? For example, the distance traveled by a Linear Bezier Curve is: distance = sqrt(pow(x[1] - x[0], 2) + pow(y[1] - y[0], 2)); But what about ...
1
vote
2answers
331 views

Anyone have experiences using Geometric Algebra

I'm working through Geometric Algebra for Computer Science, and the subject does give a clearer of picture of things like quaternions and complex numbers. I can definitely see how GA could be ...