Mathematics Stack Exchange
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Questions tagged [3d]

For things related to 3 dimensions. For geometry of 3-dimensional solids, please use instead (solid-geometry). For non-planar geometry, but otherwise agnostic of dimensions, perhaps (euclidean-geometry) or (analytic-geometry) should also be considered.

This tag is for things related to 3-dimensions. For geometry of 3-dimensional solids, please use instead . For non-planar geometry, but otherwise agnostic of dimensions, perhaps or should also be considered.

Learn more about 3-dimensional space here.

3724 questions
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Area of ABC on a plane

In the above question could anyone please explain me what they have done.
Koolman
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equation of projection of a line

In a book there is following equation . How they have witten the above projection equation
Koolman
  • 2,898
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3d grid cell calculation

i am not sure if i selected correct category for my question. Lets say i have a 2d grid. Every cell in the grid has an id which is calculated using formula: currentRow * totalColumns + currentColumn + 1. So if you have a grid with 5 rows and 4…
Ploo
  • 113
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equation of lines which intersect another line at given angle.

Find the equation of $2$ lines through the origin which intersect the line $\displaystyle \frac{x-3}{2} = \frac{y-3}{1} = \frac{z}{1}$ at an angle of $\displaystyle \frac{\pi}{3}$ $\bf{My\; Try::}$ Let equation of line be $\displaystyle…
juantheron
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Calculate height between 3 vertices

I have three points that lie on a plane $(p_{1x}, p_{1y}, h_1),\,(p_{2x},p_{2y},h_2),\,(p_{3x},p_{3y},h_3)$. I know the $x$ and $y$ coordinates of a fourth point $(p_{4x}, p_{4y})$, but need to find the corresponding $z$ value (I.e. $h_4$) so that…
Mostkaj
  • 119
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Tangent Plane to sphere using 3D

How to find the tangent plane to sphere say, $x^{2} + y^{2} + z^{2} +2ux+2vy+2wz+d=0$ from the point $P(x1,y1,z1)$ not necessarily on the sphere. If possible, solve using 3D not vectors.
user1611542
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Shortest distance between z axis and the line $x+y+2z=3, 2x+3y+4z+4=0$

z axis is : $x=0=y$ $x + B(y) = 0$ --> (1) $x+y+2z-3+ A (2x+3y+4z+4 ) = 0$ --> (2) These are two planes constructed through the two lines. We find the parallel planes so that it is easier to calculate the distance…
user1611542
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[SOLVED]vector perpendecular to normal vector

I am stuck vector related problem. I need to find a perpendicular vector(V) of fixed lentgh say 20 to other Normal vector(N) whose lentgh is unknown only direction. for N and V I know intersecting co-ordinates. all this is happening in 3D…
Shahabaz Bagwan
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Can two lines lying in different plane be parallel?

In two lines lie in different plane, can they be parallel to each other? I am thinking if two lines are parallel to each other, then their direction cosines must be same so two lines lying in different plane cannot be parallel. Am I missing…
Sid1234
  • 127
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Determine plane rotation in 3D when only knowing the length of it sides?

For an assignment in computer graphics, i need to be able to determine a plane's rotation by just holding it in front of my webcam. So basically I only got 2D coords of the plane's points. I searched the internet to find how to determine the plane's…
Diederik
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What would moving in the 4th dimension look like in 3d?

I've been reading "Shape of Space" and watching videos from the videogame Miegakure. Both talk about >3 dimensional space. I'm not sure if Miegakure's interpretation is accurate and it's limited to youtube only…
quantum
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calculate field of view from focal length

I am trying to calculate the field of view of a camera from a given focal length and film width. I am using the following equation to do this. FOV = math.degrees(2 * math.atan(filmWidth / (2 * focalLength))) From reading online, this seems to be…
ollie dunn
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how do you find the intersecting points of three $3d$ cones with origin and angle

I'm working on a project and I'm a developer. the math is a bit, well, way beyond me. I can visualize things enough to see that they should work, but that's as far as my brain can take me on this one. For this project, there are three points in a…
John Sly
  • 141
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3 answers

finding a third 3d point in a series

Given two three dimensional points. find the z coordinate of a third point that has two known coordinates. I'm not entirely sure how to solve this system. I'll be implementing this into an algorithm so any additional pointers in that direction…
hownowbrowncow
  • 113
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Efficiency in vector translation by matrix instead of vector

I try to understand math for 3D games. If I want to translate a point, I may do it in two ways: 1. Using vector summation. 2. Using matrix multiplication. For example: Initial vector $p =(1,2,3)$. has to be translated by $t=(4,5,-6)$. $p + a = p2 =>…
Dima
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