A branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.
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29 views
Reconstructing 3D Rotation from 8 byte - Assistence required
I am currently trying to load 3D models and animations into a program. The file format has no public description, so I am decoding them piece by piece. (I'm studying computer science and it's for ...
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1answer
43 views
Overlap color between objects
I'm currently trying to build a game with Ogre3D that is basically a moving vehicle that leaves a green trail (2D manual mesh) in it's path, what i'm trying to achieve is exactly what this image shows:...
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2answers
89 views
Determine the z coordinate of a deformed plane based on uv (xy) coordinates
I am using a formula to turn the following texture
into what looks like two 3 dimensional planes
The formula I am using for the texture deformation is
float2 texUV = float2(uv.x / abs(uv.y), (1.0 / ...
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1answer
38 views
Push cube outside triangle face
I'm creating a 3D game, and I need to know how to push a player (axis aligned box/cube) outside a triangle.
How can I get get the push direction?
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1answer
54 views
Move object forward according to rotation
How do I make an object (like a bullet) go forward according to its rotation in vanilla nodejs (my game server language)? For example, if an object's rotation is 0 degrees, then it goes straight up.
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0answers
17 views
FInding out if a shape is enclosed by other shapes
I'm trying to programmatically work out if a 'core' shape is surrounded with other shapes and thus no space exists around it. Here's an illustration of what I mean (ignore white gaps, they are just to ...
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1answer
58 views
Finding if 2 polygons intersect using clipper library
After realising my code was pretty inefficient at checking for polygon overlaps, I've turned to a mentioned library Clipper but finding it difficult to know hot to use it for this operation.
I am ...
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vote
1answer
40 views
Finding when shapes overlap and lines intersect but exclude points/edges
I've been looking for a c# algorithm to help determine if shapes and lines intersect but want to exclude boundary overlaps. Here's an example:
My true problem is finding if polygons intersect but ...
8
votes
1answer
132 views
Snapping shapes together in game
I'm trying to work out how to snap shapes together the player may move around on a canvas.
As the square approaches the other object, I want to pull that shape in (given a certain proximity) and have ...
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1answer
51 views
Points inside a Polygon, failing for shapes with 0,0
I've been using an algorithm (http://wiki.unity3d.com/index.php/PolyContainsPoint) to tell me if a point is inside a polygon... in fact a few variants (here and here) but they all come back the same. ...
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vote
1answer
79 views
Checking if shapes will tessellate
I'm trying to figure out where to start with getting code together to check if a shape tessellates.
An example:
Consider that the shapes cannot be rotated, just as-is. A 'compound' shape (as seen in ...
2
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2answers
62 views
Given a grid system where some coordinates are marked as impassable, how to find natural-looking car driving path between two locations?
I can compute an A* path, but I get only cardinal directions from that. A 45˚ path would look like "up 1 left 1 up 1 left 1 up 1 left 1..."
My specific question is, given a grid with a pathing ...
8
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1answer
289 views
Algorithm for “healing” multiple rectangles into a smaller number of rectangles?
Say I have a grid of rectangles of different shapes and colors and I want to reduce (reasonably close to optimal is fine, optimal is not necessary) the number of rectangles to represent the same ...
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1answer
17 views
Lengthen Line (bidirectional) - crossing zero line
I'm trying to lengthen a line, by a certain amount.
I want to apply the modification to both points on the line, expanding it in both directions. without moving it from it's current position (center ...
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0answers
23 views
Calculating the inverse mesh of a 2D mesh inside a bounding box
If I have a mesh (drawn in red below)
How can I calculate the inverse of the mesh (drawn in red below), given that the mesh is always constrained by the same four vertices of the encompassing ...
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0answers
33 views
What shapes interlock solidly like cubes?
What basic geometric shapes, besides cubes, interlock "minecraft" style like cubes?
A small edit to make question more suited to Game Dev:
I am experimenting with game dynamics to create geometric ...
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vote
1answer
104 views
How to draw an arc between two angles?
I'd like to draw an arc between two specific angles. For example, "draw an angle between 0 and 90 degrees" and it will draw only that part of the circle and ignore the rest.
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2answers
50 views
Best way to test if some point on a line if in front of another point on the same line in 3D
I have a line in 3D defined by point P0 and direction vector D.
For given input point P on a line defined as above, I want to test if P is in front of point P0. The code will be used in GLSL fragment ...
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2answers
94 views
Calculate length of isometric line
In my isometric game the user can draw a line of arbitrary length, and I need to calculate the "unprojected length" of the same line. Users can only draw lines in 6 directions (4 isometric directions ...
3
votes
1answer
62 views
Point plotting with a line graph
Please see attached screenshot.
Here's how it works.
A is a slider that goes up and down, and the red line uses the centre point of the A slider to draw its start point.
B is another slider, but ...
2
votes
1answer
34 views
Check if a 3D mesh is a rectangular prism
I have a mesh post-processor in Unity that automatically a convex mesh collider to objects that need one (mostly all).
Sometimes however there are objects that only need a box collider instead.
...
2
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0answers
27 views
What is the formula for the collision of two “stretched spheres”?
In Smash Bros Melee, hitboxes aren't perfect spheres or boxes. They are, instead, a shape that looks like a continuous line of consecutive spheres:
I.e., the geometry can represented as:
Hitbox : (...
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2answers
36 views
rough texturing on edges of mechanical parts
How do major studios fake the effect of "wear & tear" on the edges of guns and other things? I've always wondered this, but today it got to the point where I figured, why not just ask you guys. I"...
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0answers
24 views
Rotating a UI arrow according to the change in camera's rotation
I have been trying different alternatives to do what is a very basic thing but I couldn't have any success.
What I want to do is this. I have a 2D UI sprite at the screen, formed by 2 triangles, with ...
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0answers
29 views
Finding minimum horizontal offset to disjoin two objects in 3D
This is an extension of sorts of the question asked here: Allowing a player to walk up and down slopes without resistance
I am using the Separating Axis Theorem to determine the minimum translation ...
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1answer
65 views
Applying texture inside of an Icosphere?
I have implemented a code to generate an Icosphere procedurally in Unity 5.3.4f, which works pretty well. However, what I need to do know it tweak the code to make the sphere to receive texture only ...
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0answers
38 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 ...
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1answer
50 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 above.
...
3
votes
1answer
203 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 ...
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votes
1answer
72 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;
...
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vote
3answers
120 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 ...
8
votes
2answers
917 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 ...
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1answer
23 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 ...
3
votes
1answer
73 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 ...
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0answers
32 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 ...
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1answer
84 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 ...
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1answer
80 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 ...
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2answers
138 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 ...
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2answers
67 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 ...
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0answers
35 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
85 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 ...
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1answer
119 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 ...
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votes
2answers
90 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 ...
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1answer
172 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 ...
1
vote
1answer
51 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 ...
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1answer
73 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 ...
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1answer
39 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?
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1answer
135 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? ...
3
votes
1answer
137 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,
...
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0answers
111 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 ...
