A branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.

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6
votes
2answers
683 views

Perspective in early pseudo-3d games

Please take a look at the screenshot below, from the old classic Space Harrier. My question regards the curved perspective on the chequerboard 'ground'. It's got a strangely curved geometry (I ...
4
votes
1answer
542 views

rotating an object from sourceAngle to destAngle, both 0-359, clockwise or counter clockwise?

I've got a game object i need to rotate. It's current angle is player.rotation, the destination is targetAngle, both in degress, 0 to 359. I've got a function named rotateDirection(float sourceAngle, ...
8
votes
1answer
214 views

What are some ways to implement variable body shapes?

Games like Ryzom and the Sims allow players to have human bodies with different shapes: wide or thin, tall or short, big noses or small, etc. It seems to me that it'd be impractical to pre-generate ...
1
vote
2answers
496 views

Rotating coordinate system

Lets say that you want to rotate simple cube around fixed point in center. Is it possible to use such coordinate system, that you need to use only sine and cosine in order to rotate? I have done ...
5
votes
2answers
1k views

Generating geometry when using VBO

Currently I am working on a project in which I generate geometry based on the players movement. A glorified very long trail, composed of quads. I am doing this by storing a STD::Vector, and removing ...
0
votes
3answers
310 views

exact point on a rotating sphere

I have a sphere that represents the Earth textured with real pictures. It's rotating around the x axis, and when user click down it has to show me the exact place he clicked on. For example if he ...
6
votes
4answers
2k views

How do I restrict the movement of a point to within a radius of another?

I have a situation where a sprite's center point needs to be constrained within a certain boundary in 2D space. The boundary is circular, so the sprite is constrained within a radius. This radius is ...
16
votes
2answers
16k views

How can I convert a mouse click to a ray?

I have a perspective projection. When the user clicks on the screen, I want to compute the ray between the near and far planes that projects from the mouse point, so I can do some ray intersection ...
1
vote
2answers
2k views

Voronoi regions of a (convex) polygon

I'm looking to add circle-polygon collisions to my Separating Axis Theorem collision detection. The metanet software tutorial (http://www.metanetsoftware.com/technique/tutorialA.html#section3) on ...
17
votes
2answers
5k views

How do I test if a circle and concave polygon intersect?

I have a polygon (sometimes convex, but often concave), and a bunch of circles with different radii. How can I find out if a circle is intersecting/overlapping with the polygon? I could split my ...
1
vote
0answers
294 views

How can I draw a model perpendicular to a sloped surface? [duplicate]

Possible Duplicate: How do I find rotation in 3D based on a vector/normal? My models are axis-aligned. I know the normal of the surface I want to draw them on. How do I compute the ...
1
vote
1answer
304 views

Frenet frame and application

I have just been reviewing Frenet Frame math. It is an interesting geometrical issue. I know that common applications are: camera movement along a curve tube and ribbons surface Can someone ...
4
votes
3answers
2k views

Point line collision reaction

I am trying to program point line segment collision detection and reaction. I am doing this for fun and to learn. The point moves (it has a velocity, and can be controlled by the user), whilst the ...
5
votes
1answer
2k views

Morph a sphere to a cube and a cube to a sphere with GLSL

I'm getting started with GLSL with quartz composer. I have a patch with a particle system in which each particle is mapped into a sphere with a blend value. With blend=0 particles are in random ...
5
votes
1answer
4k views

How do I find rotation in 3D based on a vector/normal?

I've been playing with Blender and Python, doing basic things like accessing vertices/normals,etc. I can get the normal of each face of a mesh. I was wondering, how can I get the rotation of a face ...
7
votes
4answers
2k views

Implementing 2D CSG (for collision shapes)?

Are there any simple (or well documented) algorithms for basic CSG operations on 2D polygons? I'm looking for a way to 'add' a number of overlapping 2D collision shapes. These may be convex or ...