Mathematics Stack Exchange
Mathematics Stack Exchange

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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How to average 3D Scale Vector?

I'm working in a 3D application and I'm trying to average scale values together, but I'm missing a step. The x, y, z scale values in my problem will all be the same so even though my values will be used in the form vector$(1, 1, 1)$, for this…
terrachild
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Unreliable algorithm for determine if points lie along a line?

So lets say I have some points $A,B,C$. A method I have been shown for determining if the lie along a straight line is thus: $\mathrm{If}\space|AC|=|AB|+|BC| \space\mathrm{then\space A,B\space and\space C\space lie\space on\space a\space…
user1833028
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Determine if a point is within two planes

I have a point P and two planes defined by three vertex each. How can I determine if P is between the two planes?
user3424077
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Creating rectangle on 3D plane

I would like to create a rectangle from two given 3D points (they are placed on rectangle diagonal). Those points lies on the same plane with given normal. I was able to do it on axis aligned planes, but now I would like to do it on any plane. Any…
user1577566
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How do you get 3D gradient direction and magnitude?

I know that we can get the magnitude and direction from 2D gradient ? 1) mag(Gx,Gy) = sqrt ( Gx^2 + Gy^2 ) 2) angle(Gx, Gy) = tan^-1 (Gy/Gx) What about in 3D? 1) mag(Gx,Gy,Gz) = sqrt ( Gx^2 + Gy^2 + Gz^2 ) 2) angle(Gx,Gy,Gz) =…
Gary Tsui
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3d Transformation

I am trying to understand 3d-transformation in html5, but can't understand how we get new (x1, y1) coordinates. For example, we have a plane on our screen with a point at coordinates (287, 431). We rotate the plane around X-axes at 60 deg. So we…
user2664687
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Given a point (x,y,z) and an angle/bearing distance calculate the end point (x,y,z)

I'm not very mathematical but I'm working on a 3d program and for this part I simply want to draw a line. I know the starting vector (x,y,z), the length r of the line and the bearing/angle. I want to calculate the endpoint so I can draw the line. I…
user90960
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Uniformly selecting a subset of points (sampling?) in a bounded 3d space

I'm a master's student in Computer Science with a relatively weak background with mathematics, so please Forgive me for using a lot of the wrong terms here. This problem was related to a research topic I'm currently doing. Given a set of points in a…
Felis
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Grade 10 Level - Cube Split into 3 Equal volumes

first of all, sorry for the unspecific question, I couldn't think of a specific enough title, if there is any suggestion, I can edit the title. This question seems simple enough, but I can't seem to solve it? Two of the sections are clearly a right…
Aqila
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How to know if two lines are parallel in three-dimensional space?

How can we easily see that these two lines are not parallel? I normally compare the direction numbers to see if they are not a multiple of each other, but here I can not directly see the direction numbers of line F. $D:…
Ricardi
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Silhouette cast on a plane from a set of equal spheres

A spherical set of n spheres of equal radius r casts a shadow/silhouette on a plane. If they are far enough apart the area of the silhouette is equal to the sum of the silhouettes of the individual spheres. When they are so compressed (dense) they…
Axel W.
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What is the general name for shapes like sphere and cone?

What is the general name of the shapes you get by spinning a 2d shape around 360 degrees? e.g spinning right triangle around either short sides 360 degrees to get a cone, spinning a circle around the diameter to get sphere, etc
Overdrowsed
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How to calc 4×4 matrix that covert a set of point from one 3D coordinate to another 3D coordinate

Now $n$ points($p_1 ,\ldots, p_n$) are given in a cartesian $3D$ coordinate system: $L_1$. Actually, $L_1$ is a local coordinate system of a $3D$ model. And $n$ points($P_1,\ldots ,P_n$) are given in the other cartesian $3D$ coordinate system:…
ZhefengJin
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Calculating the coordinates of a cube at the quarter of space diagonal (body diagonal)

Can someone please help explain what the coordinates of a cube of length one at a quarter of it's body diagonal would be? I know that the coordinates of the center of a unit cube are (1/2, 1/2, 1/2) but what would be the coordinates at a quarter of…
harry
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Given two 3D points A(x1, y1, z1) and B(x2, y2, z2). Find the four vertices of a square plane which is perpendicular to line AB and centered at A

I have two 3D points: $A = (x_1, y_1, z_1)$ and $B = (x_2, y_2, z_2$). Consider A as the start point and B as the end point. There should be one and only one plane that is perpendicular to line AB and also contains Point A. I need to find the…
laopan2008
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