# 3d

1. ### Making STRONG shelves with Topology Optimization

A project, that's fun, educational, cool-looking and actually useful! What more could you want? We're making topology-optimized floating shelf brackets today...
2. ### I In what direction does a light wave vibrate?

I've wondered this for a while but not known how to ask the question, If light is a transverse wave, then what is it transverse to? To elaborate, light travels in three-dimensions, radially. To me, this seems analogous to the sound wave, with pulses of pressure moving longitudinally to the...
3. ### New metal gear 3D model in Blender

Hi, it's been a long time since I've been on these forums, but here is a new 3D blender model that I spent four weeks of daily work to finish. I'm glad it's done, it wasn't easy. This is metal gear RAY, a 70-foot tall robot from the popular video game franchise metal gear solid.
4. ### I The allowed energies of a 3D harmonic oscillator

Hi! I'm trying to calculate the allowed energies of each state for 3D harmonic oscillator. En = (Nx+1/2)hwx + (Ny+1/2)hwy+ (Nz+1/2)hwz, Nx,Ny,Nz = 0,1,2,... Unfortunately I didn't find this topic in my textbook. Can somebody help me?
5. ### B How do you create a + and π sign using multivariable (x,y,z)

I am taking a high school multivariable calculus class and we have an end-of-semester project where we trace out some letters etc., except that they all have to be connected, continuous and differentiable everywhere. My group's chosen to do Euler's formula, but so far we are having problems...
6. ### 3D file manipulation resources

Hi I am trying to learn how to manipulate 3D files like obj or stl using programming (I primarily use Python, but also know Javascript). Which resources can I use to learn this?
7. ### Which function drawer is this one?

Have anybody seen a 3D function drawer like this one?(4:12) Since I don’t know what these 3D drawers are really called,I can’t find any.
8. ### I Rotation of a point in R3 about the y-axis

Hello, I'm having a visualisation problem. I have a point in R3 that I want to rotate about the $y$-axis anticlockwise (assuming a right-handed cartesian coordinate system.) I know that the change to the point's $x$ and $z$ coordinates can be described as follows: z =...
9. ### Computer Graphics & More

Hello, I am having trouble comprehending how grids are made and defined in computers. What is the unit that they use and how is it defined ? I know that softwares use standardized units of measure (measurement) such as centimetre. Basically, how is a 3-Dimensional Space created in computers...
10. ### Plot 3D graph of electric potential of a charged particle

1. Homework Statement Plot the electric potential $V(r)$ due to a positively charged particle located at the origin of an XY plane. 2. Homework Equations $V=\frac 1 {4πε_0} \frac q r$ 3. The Attempt at a Solution I'm unfamiliar with 3D coordinates at this time, but I like to know how...
11. ### Find the equation of the plane given point and line (3D)

∴1. Homework Statement Find an equation for the plane that contains the point (1,-1,2) and the line x=t, y=t+1, z=-3+2t? 2. Homework Equations 3. The Attempt at a Solution I dont know what Im doing wrong but everytime I try to do these plane questions my amswer is always the opposite sign...
12. ### Various Properties of Space Curve...*Really need help*

1. Homework Statement Let γ : I → R3 be an arclength parametrized curve whose image lies in the 2-sphere S2 , i.e. ||γ(t)||2 = 1 for all t ∈ I. Consider the “moving basis” {T, γ × T, γ} where T = γ'. (i) Writing the moving basis as a 3 × 3 matrix F := (T, γ × T, γ) (where we think of T and...
13. ### Finding the curvature of a space curve

1. Homework Statement Find the curvature of the car's path, K(t) Car's Path: r(t) = \Big< 40cos( \frac {2 \pi}{16}t ) , 40sin( \frac {2 \pi}{16}t ), \frac{20}{16}t \Big> 2. Homework Equations K(t) = \frac { |r'(t)\:X \:r''(t)|}{|r'(t)|^3 } 3. The Attempt at a Solution This is part of a...
14. ### What variables are needed to find a moment?

1. Homework Statement You wish to find the moment at the origin produced by a force, ̅F= {Fi}̂, that is applied at r= {̂ai+bj +ck ̂}. Which variables (F,a ,b,c , ) do we need to know to find a numerical answer? Explain using math and figures. 2. Homework Equations Mo = r x F 3. The Attempt at...
15. ### I Spherical coordinates via a rotation matrix

First, I'd like to say I apologize if my formatting is off! I am trying to figure out how to do all of this on here, so please bear with me! So I was watching this video on spherical coordinates via a rotation matrix: and in the end, he gets: x = \rho * sin(\theta) * sin(\phi) y = \rho*...
16. ### 3D Fourier Transforms?

Hi, I have a FORTRAN code with an array called Chi that I want to run an inverse FT on. I have defined two spaces X and K which each consist of 3 vectors running across my physical verse and inverse space. My code (If it works??) is extremely slow and inefficient (see below). What is the best...
17. ### B 3D models of waves

I am looking for 3D (or 4D, etc.) images of waves (such as light or sound), but seem to be having difficulty locating such models. Can someone please direct me to this kind of display, or is it not something being currently done?
18. ### MATLAB Plotting a 3d function

I had a function of 3 variables f'(kx,ky,kz) and did an ifft f = ifft(f') and now i have a function where inside a small polygon the function f = 1, and outside f=0, within a cube space of length L. how do i plot a scatter graph for this function where there is a point when f =1, and no...
19. ### I How to word a 3D function?

I have, say, an ellipse in the x-y plane: (x^2/a^2) + (y^2/b^2) = 1 I want a 3d (e.g. z) function where inside the ellipse z=+1, outside z=0; the function is not continuous. so in effect what I'm left with is a large plane where z= 0, and a small ellipse cut out raised to z=1. How do I write...
20. ### I Normalizing Constant 3D Infinite Well

For time independent Schrodinger's equation in 3-D Where Enx,ny,nz=(nx/Lx2+ny/Ly2+nz/Lz2)(π2ħ2/2m and Ψnx,ny,nz=Asin(nxπx/Lx)sin(nyπy/Ly)sin(nzπz/Lz) How do I normalize A to get (2/L)^3/2? I don't think I understand how to normalize constants.
21. ### 3D Relativity Question

1. Homework Statement LOOKING AT PART (c) The ball is traveling at velocity c/√2. The car is traveling at velocity c/√2. Ball is thrown up through the sun roof or something I don't know. 2. Homework Equations 3. The Attempt at a Solution I don't know how to think about this in 3D. I've...