Tagged Questions
1
vote
1answer
67 views
Coordinate Transformation on Local coordinate system
I am having a point $P(x,y,z)$ in $3D$ with respect to global coordinate system. I want to create an another Local Coordinate System by picking three points $N1, N2, N3$ in 3D. Now I want to know the ...
3
votes
0answers
52 views
How to solve a distance problem inside of a picture?
sorry for my bad english. I have the following problem:
In the picture you can see 4 different positions. Every position is known to me (longitude, latitude with screen-x and screen-y).
Now i want ...
3
votes
3answers
276 views
Tetrahedron problem (proving)
Prove that if $P$ is the intersection of the altitudes of a tetrahedron $ABCD$ and $r$ is the circumradius then $PA^2+PB^2+PC^2+PD^2=4\cdot r^2$.
1
vote
0answers
174 views
Rotating co-ordinates in 3D
Suppose I have 3 axes, $x$, $y$, and $z$ such that $x$ is horizontal, $y$ is vertical, and $z$ goes in/out of the computer screen where $+$ve values stick out and $-$ve values are sunken in.
Suppose ...
4
votes
3answers
127 views
move a point up and down along a sphere
I have a problem where i have a sphere and 1 point that can be anywhere on that sphere's surface. The Sphere is at the center point (0,0,0).
I now need to get 2 new points, 1 just a little below the ...
4
votes
2answers
220 views
How to calculate x,y position of 3D points?
I have points in 3D system like this
$$p1=(2,3,4)$$
$$p2=(3,5,5)$$
Here I would like draw point $p1$ and $p2$ in $2D$ view.
Project type = orthographic.
Coordinate system = Cartesian
X- axis, ...
0
votes
2answers
150 views
Gram-Schmidt Orthogonalization - does it distort?
I am writing a 3D solar panel positioning programme and have a section of code where I use the Gram-Schmidt Orthogonalization process to go from 3D to 2D for easier calculations.
(For reference, here ...
0
votes
1answer
98 views
how to get rotation component of quaternion form using 3d coordinates
I have a series of 3d coordinates distributed in a 3d space according to a root point. I can determine the x, y , z component using reducing the vectors. but I am not clear how to get rotation ...
0
votes
1answer
72 views
Z-index of an arbitrary point on a flattened 3-dimensional triangle
I have a triangle in a 3-dimensional coordinate system that I want to draw to a screen. I'm able to flatten the triangle to 2 dimensions and determine whether an arbitrary point on the screen falls ...
0
votes
1answer
690 views
Finding an equation of a sphere for a specific plane
I am not sure how to proceed with this question from Stewart's SV Calculus text:
Find equations of the sphere's with center $(2, -3, 6)$ that touch (a) the $xy$-plane, (b) the $yz$-plane, (c) ...
2
votes
0answers
247 views
How are 3D coordinates transformed to 2D coordinates that can be displayed on the screen? What is the formula for this?
The title asks it all, and could someone please also explain the formula as well? Thanks.
0
votes
2answers
726 views
How do I map a 3D triangle into 2D?
The problem I'm having is mapping a 3D triangle into 2 dimensions. I have three points in x,y,z form, and want to map them onto the plane described by the normal of the triangle, such that I end up ...
