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

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0
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1answer
14 views

How to calculate the magnitude of the drag in Corona-sdk?

I'm making a game on Corona that launches a ball. The force is based on the magnitude of the drag: the larger is the drag -> the higher is the force. I'm having some trouble to do this, because I ...
4
votes
1answer
442 views

How can I mask this CanvasRenderer?

I'm creating a text box that allows for selectable text, based off of Unity's InputField. An issue I am now facing is that the selection highlight does not respond to masks (The parent has a mask, but ...
1
vote
0answers
13 views

HLSL topology mismatch question

I'm trying to write a fur shader with the shells & fins technique. Currently I receive this DirectX error D3D11 ERROR: ID3D11DeviceContext::DrawIndexed: The declared input primitive type in ...
0
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1answer
45 views

Draw a square given 2 corners

I am at the moment trying to come up with a simple method to extract some data points, given two corners. A*************** **************** ***************B I tried to illustrate my situation ...
11
votes
2answers
5k views

How can I project a 3D point onto a 3D line?

Let's say I have a line defined by two points, A and B, both in the form (x, y, z). These points represent a line in 3D space. I also have a point P, defined in the same format, that isn't on the ...
2
votes
1answer
126 views

Could triangles be used for swept-AABB checks between positions?

I'm trying to understand swept-AABB collision detection. When checking for collisions between two positions of an object, I commonly see one of 3 strategies used: Rays: trace rays from parts of the ...
0
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1answer
33 views

How to find a point on a plane?

I'm using unreal engine 4. Currently I ray trace to a surface in game and I'm trying to find the location of the point relative to the surface1 instead of the world. I have the world position of the ...
-3
votes
1answer
50 views

Why do I have to do minus-equals for the x-coordinate but plus-equals for the y-coordinate?

I found a simple script in C# in Unity5 to make the camera follow the mouse: xRotation -= Input.GetAxis ("Mouse Y") * lookSensitivity; yRotation += Input.GetAxis ("Mouse X") * lookSensitivity; ...
0
votes
3answers
71 views

LibGDX - Trying to make a radar-like display

i have an interesting question about geometry. I have two or more moving objects outside of my stage's viewport (blue and red circle in the image below), which i want to point at with two arrows on ...
1
vote
1answer
155 views

Most efficient way to calculate angle between two line-segments that do not necessarily touch each other

Although I found answers on calculating angles from vectors, I didn't find a specific way to calculate angles between line-segments that do not necessarily touch each other (I say "not necessarily ...
5
votes
2answers
6k views

How do I use the dot product to get an angle between two vectors?

I am learning to use normalized vectors in my games. I've learned that in order to know the angle between two vectors, I can use the dot product. This gives me a value between -1 and 1, where 1 ...
8
votes
2answers
871 views

Get water flow direction vector from water normal vector

Im stuck developing an important detail of my game water: Making it flow downwards! Considering a typical 3D world in wich water tends to go towards gravity g=(0,-1,0) , and having the normal of the ...
1
vote
2answers
79 views

How do I calculate the tangent to a point on a circle?

I have a line that is from the center of a circle to a point on it's edge that is changing constantly (radius is drawn to a point orbiting a circle) I want to make a line tangential to the circle ...
0
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0answers
26 views

How to convert Non-Axis Aligned Bounding Boxes to AABB

I'm trying to write a raytracer to render boxes (cubes) that are arbitrarily rotated, i.e. not necessarily axis aligned. While I'm reasonably comfortable ray-tracing an axis-aligned cube, I don't know ...
3
votes
1answer
64 views

Vertex normals in the geometry shader using directx

I'm in directx 11 with the geometry shader. Is is possible to calculate vertex normals? Just one like segment per vertex? In the geometry shader? I did vertex normals per face, this is what I got, ...
0
votes
1answer
68 views

What technique should I use to implement the following type of “diggable” terrain?

I'm trying to replicate a certain game mechanic from the game Diggles. This game takes place in a vertical cross-section of the earth and allows the player to dig tunnels and caves into the ...
9
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2answers
4k views

How do I determine if one polygon completely contains another?

I have 2 polygons. I know the vertex coordinates of both polygons. What's the best way to check if one is completely inside the other? For example, the algorithm should only recognize the black ...
0
votes
1answer
53 views

Normal to an edge of a polygon, from a point inside the polygon

Suppose that I have a closed boundary that is represented by n points. Using these n points I construct a polygon with n sides. I have a point P(x,y) that lays inside the polygon. I want to draw the ...
1
vote
1answer
77 views

Best way to find line segment intersection

I need to find the point of intersection between two line segments in 2D space. I receive them in terms of both coordinates of both lines. Because they are line segments I would also need to know if ...
3
votes
2answers
63 views

Calculate total area of a composition of images

I'm trying to calculate the total area of a game object composed of several images. For each image, I know: Width, Height X, Y Rotation ScaleX, ScaleY OriginX, OriginY Where OriginX/Y are floats ...
-1
votes
2answers
1k views

How does atan2 work when getting angle of a vector?

I know that atan2 gives me the absolute angle of any vector. But it doesn't give a value from 0 to 360 degrees. Instead, it gives a value (if I'm not mistaken), between 0 and 180, or between 0 and ...
0
votes
0answers
31 views

How to find visible planes in a world of boxes

I have a world where each object is a box: Each box has position x, y=0, z, dimensions width, height, depth. The boxes are never rotated. Each box is composed of 5 planes (left, right, front, back ...
3
votes
1answer
63 views

Super formula on shader

I'm using Shader-toy to experiment and try to learn a bit the shader science. As exercise I wan to replicate some of the wikipedia math plots. I've started with a Super Formula. What I want to ...
-1
votes
2answers
79 views

Help with drawing a polygon with N sides [closed]

I am at university on my games development, and I have been given work to fill in an empty pixel plotter program using the methods they have supplied for it to teach us the algorithms used in 2 ...
0
votes
1answer
116 views

How could we use trigonometry for moving around a 3D World?

Well I have a question about geometry and 3-Dimensional player movement in general. I'm using Java, OpenGL and LWJGL. This is basically what I got: currentFrontSpeed: Is a float that contains the ...
7
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3answers
3k views

Moving a particle around an Archimedean spiral at a constant speed

I want to move a particle in a spiral at a constant speed. Note that that is not a constant angular speed. This is proving rather difficult, and I'll go through my method so far below. The spiral in ...
0
votes
1answer
34 views

How to enforce touching within a ring shape?

I'd like to have the player moving the finger within the shaded ring: The game should be able to detect "out-of-boundary" events once the finger moves outside the ring. How can I accomplish this?
0
votes
1answer
73 views

What is the Z plane?

I am learning the basics of geometry shaders and I came across references to the "Z plane." It's pretty easy to visualize the X and Y planes, but where does the Z plane reside in Cartesian space? ...
1
vote
1answer
50 views

What is the best way to check for intersection of two bounding boxes, given a minimum and maximum Vector3 for each one

I have a BoundingBox object which holds two Vector3's (x, y, z), one for the minimum point and one for the maximum point. (-1.5 0 9 | 1.5 3 10) What is the best way to check for any intersection or ...
1
vote
1answer
51 views

How can I fade in 3D foliage smoothly?

Take a look at this picture: This is a picture of me diving down from a high height. As you can see, the world is a simple world with grass, snow, trees, etc. The problem here is the 3D foliage. If ...
1
vote
0answers
65 views

2d grid vision(eye sensor) for a neural network bot?

I have a 2d grid and neural network bots living above it. What is a good way to give them vision of tiles in front of them? Below I describe my idea that I don't know how to efficiently(or ...
4
votes
1answer
65 views

What is the fastest way of drawing simple, textured geomtries and keeping the depth test?

I'm looking for a fast way to draw simple 3D geometries - that will consist of up to 10 vertices. Each of them will have a texture (though varying between geometries). I also want to store the ...
0
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0answers
61 views

Project 2d click/touch onto 3d plane

I have a 3d scene that contains an infinite plane that is NOT parallel to the camera (so every screen coordinate corresponds to a point on this plane- in other words, there are no possible invalid ...
4
votes
2answers
158 views

Generate Geodesic Sphere from Hex and Pentagons

I have two polygonal meshes, a hexagon and a pentagon (They are tiles in a strategy game). I want to use them to construct a geodesic sphere ...
5
votes
2answers
107 views

List cells in a 2D grid that belong in a sector / portion of a circle

Are there any algorithms to find out which cells in a 2D grid lie inside/is part of a slice of a circle - a pie slice shaped region? Essentially, as per image below, I need to list out all the green ...
0
votes
0answers
38 views

How to generate tangent and binormal(bitangent) of a triangle polygon mesh

I am currently using FBX sdk to acquire mesh information from obj and fbx files. However, not all meshes contain tangent and binormal(bitangent) information so I have to use the method ...
1
vote
2answers
9k views

How do I add an image inside a rectangle or a circle in JavaFX?

Suppose we have a rectangle called r Rectangle r = new Rectangle(40, 20); and an image called image Image image = new Image("...src for image"); How do I fit the image inside the rectangle? ...
5
votes
4answers
227 views

Creating force shields: the most efficient way of deforming/reshaping a simpler convex mesh so it envelopes a complex mesh?

So, the best way I can think of how to explain what I need is the following (images used here are just random images found trough google image search). What I am trying to create during run-time is ...
7
votes
0answers
110 views

Dual Contouring - Finding the feature point, normals off

I am following this tutorial to implement Dual Contouring http://www.sandboxie.com/misc/isosurf/isosurfaces.html My data source is a grid 16x16x16; I traverse this grid bottom to top, left to right, ...
2
votes
1answer
44 views

Finding vector from a vertex to a plane

I am trying to implement Dual Contouring, following serveral sources, mainly http://www.sandboxie.com/misc/isosurf/isosurfaces.html but now I want to implement finding the feature point as explained ...
5
votes
2answers
101 views

How to find out the vertices of the polyhedron formed by the overlapping area of two rotated boxes?

What is the most efficient way for finding out the vertices of the polyhedron formed by the overlapping area of two rotated 3D boxes? If it is still confusing what I mean by "polyhedron formed ...
2
votes
2answers
120 views

Most efficient way to get the world position of the 8 vertexes of a Box Collider (C#)

What I am looking for is the most efficient way to get the world position of the 8 vertexes of the Box Collider of a freely rotated Gameobject. I cannot use collider.bounds since object is rotated, ...
5
votes
1answer
140 views

Finding new position after collision with multiple colliders

What is the most accurate way to find the correct position to where a moving character should be re-positioned as a collision-resolution, after it has collided with multiple colliders? The figure ...
8
votes
4answers
694 views

How do I efficiently check if a point is inside a rotated rectangle?

Part for the sake of optimization, part for learning purposes, I will dare to ask: How can I most efficiently check whether a 2D point P is inside a 2D rotated rectangle XYZW, using C# or C++? ...
13
votes
3answers
755 views

Are the first three values that describe a 3D plane actually a 3D vector?

A 3d plane is typically defined as a,b,c,d. Are a,b,c actually the x,y,z coordinates of a 3d vector, with d defining the rotation of the plane, something like axis-angle rotation data?
19
votes
5answers
1k views

How can I tell whether an object is moving CW or CCW around a connected path?

Lets say we have a jagged shape: And two creatures moving along it's outline. Then we smooth the shape completely by pulling the corners out. We get this: It is easy to see now that Orange is ...
1
vote
1answer
585 views

How do I calculate the distance between a point and a rotated rectangle?

This question is similar to another one about axis-aligned rectangles. However, I specifically want to calculate this for rotated rectangles. I have a rectangle with a (cx, cy) for the center ...
14
votes
6answers
6k views

How do I calculate distance between a point and an axis-aligned rectangle?

I have a 2D rectangle with x, y position, height and width, and a randomly positioned point nearby. Is there a way to check if this point might collide with the rectangle if it is closer than a ...
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 ...
2
votes
1answer
92 views

Realistic angular velocity for rolling sphere in Unity 5.1

I'm trying to make a small 2D game with a rolling ball/sphere using Unity 5.1, but if find the angular velocity of the ball weird. On this first image (http://imgur.com/8wBoGms), you can see the ...