# What is 3d: Definition and 1000 Discussions

In 3D computer graphics, 3D modeling is the process of developing a mathematical coordinate-based representation of any surface of an object (inanimate or living) in three dimensions via specialized software.Three-dimensional (3D) models represent a physical body using a collection of points in 3D space, connected by various geometric entities such as triangles, lines, curved surfaces, etc. Being a collection of data (points and other information), 3D models can be created manually, algorithmically (procedural modeling), or by scanning. Their surfaces may be further defined with texture mapping.

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1. ### Which software to use to create this graph?

So I have a dataset with 3 variables -Time -Quantity 1 -Quantity 2 Currently I have all the data in an excel sheet. So for example, I can easily in excel create a line graph that shows me quantity 1 on the Y axis and time on the X axis... however I want to see all 3 at the same time. So my...
2. ### B What does 3-dimensional space deform into, in the presence of gravity?

I have no expertise in this area, other than rudimentary concepts. The following might apply if the visualization of space, as depicted below, represents actual reality, but I don't know for sure. Please help me understand better, you guys! 2-dimensional space The curvatures deform into the...
3. ### I How can I model squeezed states in 3D optical modelling software?

I would like to model squeezed light and its evolution (such as when passing through lenses after being generated) using optics software such as OptiFDTD or ZEMAX. However, I don’t see any way to make such states…my plan was to simulate an Optical Parametric Amplifier to generate these states...
4. ### Need a 3d scatter plot with connected lines

Need a the source file of a 3d scatter plot with connected lines like attached figure
5. ### 3d plot of interference from 2 wave sources with 2d grid surface

Desired output similar to image, but without the objects and with better wave interference: I tried plugging the following into wolfram (I specifically want the values to be adjustable): plot z= H*e^(-m*sqrt((x-a)^2+(y-b)^2))*sin(k*(x-a)+k*(y-b) -w*t) +...
6. ### Exploring Equation of a Straight Line in 3D Space

Can we say, (y + z ) x1 = (y1 + z1) x is also an equation of a straight line in 3 dimensional space, where (x1,y1,z1) and (x,y,z) are the coordinates of a given point and a variable point respectively on a 3D line that passes through the origin, have seen equation of a straight line in 3...
7. ### Geometry Books about 2D and 3D figures with explanations and problems?

I am looking for books that contain explanations (or to be able to answer) about something like this: 1) Exterior Angle Bisector Theorem The external angle bisector of a triangle divides the opposite side externally in the ratio of the sides containing the angle. This condition occurs usually...
8. ### A Metric of a Moving 3D Hypersurface along the 4th Dimension

Consider a hypothetical five dimensional flat spacetime ##\mathbb{R}^5## with coordinates ##x, y, z, w, t##. Now imagine that the hypersurface ##\Sigma =\mathbb{R}^3## of ##x, y, z## moves with constant rate ##r## along the coordinate ##w##, i.e. ##dw/dt=r##. Assuming that ##t \in (-\infty, +...
9. ### B Calc Excess Rad on Earth in Curved 3D Space | Feynman Lectures 6-2

I'm reading the Feynman lectures chapter on "Curved Space", section 6-2. Say we're trying to figure out a way to measure average curvature on Earth. We know that 3d space is curved if Euclidean geometry rules don't work - e.g. the ratio of circumference and radius of a circle isn't ##2\pi##, or...
10. ### I 3D Printed Piston | Lower mass = Power

This is a piston I had DMLS printed from AlSi10mg - the geometry is derived from generative design using some basic inputs and a starting shape. It's really just an experiment whether a consumer grade design and print can be bolted in and work for a time. After machining, it is predicted to...
11. ### A Understanding 3D Doppler Shift with Satellites

I am trying to understand a case of doppler shift if I have two satellite circling the earth with different velocities but the same direction and with different altitudes as well. How I will be able to figure out the doppler shift in three dimension between the two satellite if one of the...
12. ### Engineering [Intro Dynamics] How to obtain v(t) from v(r) in 3D?

We know that in 1D, we can perform the following steps to obtain velocity in terms of time if the velocity is a function of position: $$v=f(x)$$ $$dt=\frac{dx}{v}$$ $$t_2-t_1=\int_{x_1}^{x_2}\frac{dx}{v}$$ $$x(t)\rightarrow v(t)$$ But I wonder if it is possible to obtain ##\vec v(t)## from...

14. ### This is a 3D model I made of a nuclear power plant control room

I spent the past several weeks making this 3D model of a nuclear power plant control room.
15. ### I General solution of 1D vs 3D wave equations

For the 1 dimensional wave equation, $$\frac{\partial^2 u}{\partial x ^2} - \frac{1}{c^2}\frac{\partial ^2 u }{\partial t^2} = 0$$ ##u## is of the form ##u(x \pm ct)## For the 3 dimensional wave equation however, $$\nabla ^2 u - \frac{1}{c^2}\frac{\partial ^2 u }{\partial t^2} = 0$$It appears...
16. ### B The 3D Universe: A Speck in the 4D Universe

Assume a TV screen or a book page represents 2D information viewable within our 3D world. From our 3D world, we see the entirety of the 2d world...all of it. Now imagine if somehow we lived within the 2D TV or book page. From our 2D world, we would be incapable of viewing, interacting or...
17. ### I Investigating a 3D Color Hue Phenomenon with Blender and Just Color Picker

I have been doing some 3D computer graphics modelling and I have observed a phenomenon I cannot find anything about. I am using Blender (free 3D program). I am also using "Just Color Picker" which is a free Windows tool that let's you check the hue/saturation/value (HSV) for any color on your...
18. ### 3D electrical discharge creation (Zap Energy's Z-pinch)

This is less of a nuclear physics question and more of an EE one, but I think this is the right place for it. There is a startup called Zap Energy and their approach to fusion is to create a inertial confinement pinch with an electrical discharge. This is a bit similar to what the Sandia labs...
19. ### Creating a grid type 3D data array from data points

I have a 3 data column ##(X, Y, Z)## ranges from ##(min, max)##. For example, ##X = (0, 5)##, ##Y=(0, 3)##, ##Z=(0, 2)##. By using them I need to create a numpy array in the form of ##[(0, 0, 0), (0, 0, 1), (0, 0, 2), (0, 1, 0), (0, 1, 1), (0, 1, 2), (0, 2, 0)...]## So in total there will be...
20. ### Electronics Stationary 3d scanner using a standard camera

I know there are some stationary 3d scanners like this, but they are really expensive. When I saw, well an addition to handheld 3d scanner - a robotic hand, I came up with an Idea that same can be done with a simple camera, and photogrammetry. Found a nice article about photogrammetry on the...
21. ### 3D Printed Metal Custom Tool Request

Does anyone on here have a 3D printer for metal? I'm looking to get a custom made socket wrench fabricated for 10 mm bolts or nuts. I'm looking for one that is extremely low profile. I don't care about the drive style (1/4", 1/2", 3/4", 1", external hex etc). The smallest mass produced one I...
22. ### B Can an Object with N Dimensions Exist in N-1 Dimensions?

I am concerned that this question may instead be a philosophical one although if it it mathematical, any insights would be very appreciated. The question is this; could an object of N dimensions exist entirely in N-1 dimensions? In other words, could an infinitely flat object have 3 degrees of...
23. ### COMSOL simulation of a 3D Ferrite Bar Numerical Model For Magnetic Flux

Hi, I am willing to simulate a 3D ferrite bar transmitter and reciever where coupling coefficient k and Bt magnetic flux density on the each side uses the finite element method for solving partial differential equations. The Magnetic Fields module has equation (jωσ − ω2ε0εr)A + ∇ × H = Je...
24. ### I Understanding Landau Levels for 3D Fermionic Gas in Magnetic Field

I am a beginning graduate student and I've been assigned a paper which uses landau levels for 3d fermionic gas in uniform background magnetic field. I am having trouble finding a proper source which deals with solution of dirac equation in such a case. With the two papers that i have found which...
25. ### I Calculating distance (from magnet) to an arbitrary point in 3D space

So I'm looking for some advice on a problem that I am trying to solve for a project. I'm an engineer but my background in vector mathematics is very minimal so I'm looking for some assistance. Lets assume we have a permanent magnet. We know the characteristics of this magnet, such as it's...
26. ### When to consider body fixed reference frame

Hello I am studying mechanics and I have been reading about having the reference frame fixed at a certain point, body fixed and also the gyro equations. I an identify the gyro case easily as I am looking for an AAC body which rotates about an axis. I am confused about the other two cases in...
27. ### Find the shortest distance between the given vectors in 3D

This is a textbook problem...the only solution given is ##3.##...with no working shown or given. My working is below; i just researched for a method on google, i need to read more in this area...use of the directional vector may seem to be a more solid approach. Ok i let ##A=(6,-4,4)##...
28. ### I Understanding 3D circle parameterization

Hey I saw this post: https://www.physicsforums.com/threads/general-equation-of-a-circle-in-3d.123168/ trying to understand 3D circle parameterization. I saw the formula given by Hootenanny But I didn't understand it and would like some help. What are u and n and how can I find/calculate them...
29. ### Engineering What is the Definition of Aspect Angle in 3D Motion?

Hi all, a bit confused with regards to the whole term aspect angle. Most examples that I searched online involved either a 2D plane or a stationary object. In this case: Let's say the man is facing the ball. In this case, the ball is being thrown from the right to the left. Since the man is...
30. ### A Projection of 3D Plane from a certain perspective on the 2D Plane

Hello all! As seen in the summary, I'm not sure if anyone can understand, but I will try to make this as clear as possible. Working in the 3D Plane: Given that there is a trajectory motion in the 3D Plane, and I have the coordinates of the motion at every 1s interval. This means at t=1s, the...
31. ### Engineering Helmholtz pair, magnetic field in 3D

As far as I can tell, the shape looks like a cuboid with 8 arms pointing in all directions.
32. J

### A Why do the Navier-Stokes equations give us non-existent results for 3D flow?

Navier-Stokes equations for 3D flow gives us wrong/non existent results, results that don't exist in nature. Does that mean equations that describe flow of fluids in a wrong way or how we can explain this situation? Because math is allways 100% correct, 2+2 is always 4, math is apsolute TRUTH...
33. ### I Finding vertex of a 3D Triangle on a Plane

I came across the following problem and wondering how to solve it. There is a plane n1x + n2y + n3z + n4 = 0 where n1, n2, n3, n4 are known. The triangle is in this plane. We already know the two vertices P1(x1, y1, z1), P2(x2, y2, z2) of the triangle. Now we have to find the third vertex P(x...
34. ### [Structural Dynamics] How to model a 3D wing as a 2D Wind Tunnel Model

Greetings Good People, As the title suggests, I'm having some trouble getting to a 2D model. The process is to select an aircraft (or wing model), and model it as a 2D, 2DOF wing-tunnel model. The aircraft I selected was a Cessna 172. This had a tapered wing, which after some calculations and...
35. ### I Equation for circle points in 3D

Hello, I am trying to solve a problem and I would like to ask for help. I have 3 points (A, B, C) in 3D space that are assumed to be on a circle. EXAMPLE 1 EXAMPLE 2 My goal is to create an algebraic formula to calculate the coordinates for 10 points on a circle composed of ABC points at...
36. ### I Excellent 3D Graphics thing at math3d.org

May I recommend math3d.org as a website for making 3D-Graphics for fresh_42's page on List of Online Calculators for Math, Physics, Earth and Other Curiosities. I also might recommend cloudconvert.com to make .gifs. It is simpler than ezgif.com, mainly because it is not so feature rich. Here...
37. ### I Surfaces wrapped around a cylinder for 3d printing

Hi All, I am looking to determine how these Vases where modeled using maths on this webpage https://www.3dforprint.com/3dmodel/sine-wave-vase-generator/2116. It looks like the surface is parametrically defined and wrapped around a cylinder. Interestingly he mentions "Sine waves combine to...
38. ### A Coil excitation adjustment on 3D Ansys Maxwell transient analysis

Hi. I am making a 3D Ansys Maxwell project to design DC electromagnet. My model as in attached pictures. I have couple of questions. 1- How important the width value of sheet of coil terminal? Altough I did not change number of conductors and current of coil, changing the width of sheet of the...
39. ### I How Do Ashcroft and Mermin Derive the Conversion from Equation 22.6 to 22.9?

Hi all, I'm reading through Chapter 22 of Ashcroft and Mermin and am having difficulty deriving an equation. Could someone please show me (or outline the steps) how Ashcroft and Mermin convert the quadratic term in Eqn. (22.6) to Eqn. (22. 9)? (pictures attached). Thanks in advance :)
40. ### I Curvature of 3D Graph on Point w/ Directional Vector

I know curvature (k) of a 2 dimensional graph y(x) is equal to y''/(1+(y')^2)^(3/2), were y' is the first derivative of y with respect to x, and y'' is the second derivative of y with respect to x. Is there a formula for the curvature at a point on a 3 dimensional graph z(x,y)? The curvature...
41. ### I Vector and Plane Relationship in 3D

I have a quick question. If a Vector is contained inside a plane, would the normal of the plane be orthogonal to said vector? Thank you!
42. ### Maxwell 3D number of conductors question

Hi guys, I wonder when I have defined the strand number of litz wire in copper material properities in Maxwell 3D, should I keep number of conductors in coil terminal added in a winding the same as number of of litz strand? For example, 2 for strands litz wire and then 2 for number of...
43. ### 3D Laplace solution in Cylindrical Coordinates For a Hollow Cylindrical Tube

Here is the initial problem and my attempt at getting Laplace solution. I get lost near the end and after some research, ended up with the Bessel equation and function. I don't completely understand what this is or even if this i the direction I go in. This is a supplemental thing that I want to...
44. ### Here is a 3D model I made of a large industrial steam turbine

This is a 3D model I made of a large industrial steam turbine. It was modeled after one of the turbines at the Port Richmond generating station in Philadelphia Pennsylvania. I plan on modeling the entire turbine hall of that power plant, but that will take several months, at least. The program...
45. ### How to picture a radial field around a 3d object?

Hello! First off, for a), I am not too sure how to picture a radial field around a 3d object. I know that this spherical metal dome is basically a enlarged version of an atom, but since with problems on radial field around an atom, I don't have to consider its diameter, I'm not sure how the...
46. ### Smoothing 3d prints with acetone

I'm in the process of 3d printing some injection molds, and I was looking at some tutorials for surface smoothing with evaporated acetone. My concern is that some of my models have concave features that the acetone will not reach. Is there a dilution that will still be effective? Alternately...
47. ### Vector space and 3D flow field

Could someone explain the green highlight to me, please?
48. ### Here is a 3D model of 13th century French cathedral that I made

It's the Saint-Etienne cathedral in Auxerre France. Created using Blender 2.92, rendered in cycles render.
49. ### I Why is this 3D operator with degeneracies only giving me 2 eigenstates

The matrix representation of a certain operator in a certain basis is $$\begin{bmatrix} 1 & 0 & 0 \\0 & 0 & -i \\ 0 & i & 0 \end{bmatrix} .$$ The eigenvalue problem leads to this equation 0=det\begin{bmatrix} 1-\lambda & 0 & 0 \\0 & -\lambda & -i \\ 0 & i & -\lambda \end{bmatrix}...
50. ### Weakly interacting Bosons in a 3D harmonic oscillator

1. Since N is large, ignore the kinetic energy term. ##[-\mu + V(r) + U|\Psi (r)|^2]\Psi (r) = 0## 2. Solve for the density ##|\Psi (r)|^2## ##|\Psi (r)|^2 = \frac{\mu - V(r)}{U}## 3. Integrate density times volume to get number of bosons ##\int|\Psi (r)|^2 d\tau = \int \frac{\mu -...