3d Definition and 1000 Threads

Let ## E=\left\{ (x,y,z) \in R^3 : 1 \leq x^2+y^2+z^2 \leq 4, 3x^2+3y^2-z^2\leq 0, z\geq0 \right\} ## - Represent the region E in 3-dimensions -represent the section of e in (x,z) plane -compute ## \int \frac {y^2} {x^2+y^2} \,dx \,dy \,dz## the domain is a sphere of radius 2 with an inner...

##z^2\leq x^2+y^2, z\geq x^2+y^2## I know the shapes of those inequalities, but the question is: How do i find if the point are external the shape or internal?

Hi I have noticed that while I have the grasp of the theoretical underpinnings of linear algebra, I need work on applying it to geometric problems (think computer vision and rigid body motion). So, I am looking for a book that allows me to practice 3D geometry problems. Is there any obvious...

I am uncertain if this belongs in the differential geometry thread because I don't know what area of mathematics my question belongs into begin with, but of the math threads on physics forums, this one seems like the most likely to be relevant. I recently watched a video by PBS infinite series...

How did you find PF?: Google Hi, I'm looking for advice on how to simulate a golf ball rolling on a green. The green will have been scanned using a 3d scanner by an Engineering Surveyor. I'm trying to model putting a golf ball from any position on the green, looking for a path line to the...

This seems like a trivial question at first, but I am struggling how to get it right. If I have 2 GPS (lat, lon, height) observations P1 and P2 taken at some height from the Earth's surface, how do I calculate the straight line distance between them? I am using the picture below to illustrate...

Hello, When creating a curved object in Tinkercad, something like a sphere, the spheres' surface does not look very smooth but rather meshy under close inspection. Will the 3D printed version of that sphere designed in Tinkercad have a smoother surface than the meshy surface it has in the...

Hello ! I want to solve the 3D Poisson equation using spherical coordinates and spherical harmonics. First I must solve this : ##d^2\phi/dr^2 + 1/rd\phi/dr - l*(l+1)/r^2 = \rho (r)## with ##\phi (\infty ) = 0## (here ##\phi## is the gravitationnal potential and ##\rho## is the mass density)...

This took roughly two months to complete from start to finish. Link to imgur album so that the full-size photos can be viewed. Rendered in 4K.

Here is an interactive 360 degree panoramic photo of a 3D computer model I made of the RBMK-1000 nuclear reactor central hall. The refueling crane is a work-in-progress. https://www.artstation.com/artwork/A9BAJm

Since the spherical wave equation is linear, the general solution is a summation of all normal modes. To find the particular solution for a given value of i, we can try using the method of separation of variables. $$ ψ(r,t)=R(r)T(t)ψ(r,t)=R(r)T(t) $$ Plug this separable solution into the...

Hello, I am dealing with bed Leveling and calibration (I guess they are the same process) of my new 3D printer and I realized I am shaky on a few basic concepts: Leveling: bed leveling does not mean that the building platform is leveled with respect to the ground, which is what a bubble level...

Hello, The first step in 3D printing is the generation of a 3D model using a CAD software. But to be able to print the object, the CAD software is not enough, even if the file is saved in .stl or .obj format, correct? Another software, called the slicer, must then receive the 3D modeling file...

Good day! I need your advice in computer graphics :smile: I have been studying and working in Autodesk 3ds Max for years, mainly for my pleasure. Now I want/need to study some new 3D program in CG, however not for just fun but for science. Particularly I need such program that enables showing...

Here is a 3D model (blender 2.8) I created of the Chesapeake And Ohio Allegheny 1601 steam locomotive, which remains today the largest locomotive ever built.

Homework Statement: heating air in a chamber Homework Equations: heating equations Hi to everyone, I want build a chamber for my 3d printer, the structure is a cube of 0.5m per side. Inside there will be the 3d printer that has a plate of 220mm x 220mm and 3mm thick that stays at a constant...

My school recently got an industrial robot arm with a precision turntable. I was thinking how to use this with some cameras/lasers to make a 3d scanner. Where would you folks recommend I start looking?

I can do question a but not b nor c. Any help would be greatly appreciated

:warning: Sigh. Yet another hazard to worry about. You can just order a 3D printer online, plug it in, and start using it. But you shouldn't do that until you provide adequate ventilation.https://www.zdnet.com/article/volatile-compounds-3d-printing-has-a-serious-safety-problem/

I've got the solution to the question but I just need more detail. I can't work out the first step of the solution to the second step. That should read, I don't know what they multiplied ih-bar by to make it (i/h-bar)^2?

Here is a 3D model I made of a nuclear reactor and reactor core.

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...

https://www.inverse.com/article/58175-study-shows-the-milky-way-is-warped

How to calculate the eletrostatic potential on a 3d object, for example a ring, if it is charger with some "Q" charge what is the potential on the surface of the ring?And how do i calculate it based on the charge of the ring?

Hi, I am looking for the solution of the following heat conduction problem (see figure below): the geometry is the semi-infinite domain such that (x,y)∈R2 and z∈[0,∞[ ; the thermal diffusivity is constant; the domain is initially at a temperature of 0; At t>0, a small square of the surface...

https://www.youtube.com/channel/UCJ0yBou72Lz9fqeMXh9mkog

Hi, so earlier this week I was given a physics research project for over the summer- I naturally thought to do 3D printing as I have a printer at home. Basically, I’ve got the general idea nailed and I’ve done a fair amount of writing for this, but I need specific physics concepts/ideas or at...

This took me almost a month to make. It's a CGI model (blender 2.79) of the Colorado lounge, which is part of the Stanley hotel in Estes Park, Colorado. The room was featured in the 1980 Stanley Kubrick horror film "the shining". I was plumb out of ideas for what to make next in 3D, but I saw...

Hi guys, I am new to this phorum and Ansys Maxwell as well. I am trying to pass as an input a time dependent current, but I really do not know how to do it. Does anyone know how to fix this issue? Cheers, Alessio

My textbook states that all the 14 bravais lattices have one of the 7 types of parallelepiped (7 crystal systems) that can be used as an unit cell. However in case of 3D HCP textbooks don't talk about this parallelepiped, rather they consider a hexagonal prism as the unit cell. Why is it so...

Summary: The new HBO miniseries inspired me to use blender 3D to re-create the Chernobyl control room. The HBO miniseries about Chernobyl inspired me use a 3D modeling program called Blender to re-create the RBMK-1000 reactor control room of the Chernobyl nuclear power plant. It's about 95%...

Hello Got a following problem. 300N Box on a frictionless inclined plane. The plane itself is in the Z-direction. Box is held by a rope AB and a force in the direction Z. Determine the tension in the rope and the force F. The answers to this problem are 104N and 215NMy question is where do i...

Hi, everyone! I read an online article, some time ago, on the Holographic Universe, and how it might operate. According to the author, quantum bits, or"qubits"of information exist on the surface of a cosmological horizon. Complex interactions between these qubits result in them becoming...

Hi PF! I have a 3D surface that changes with time. I am trying to make a movie. The following is what I do, but the output is extremely low quality. Does anyone know how I can get the same quality that Mathematica uses for its images? mov[t_] := Show[ParametricPlot3D[{(2 + Cos[v]) Cos[U]...

I'll preface this by saying I've done these sorts of problems before (though it was only in 2d) in my statics and dynamics class. I have no idea where my book went and the major problem I'm dealing with is vocabulary, so if I say something that doesn't make sense, please let me know, I've almost...

I have computed the total length of a 3D triangle and its area. The code is shown below. I want to use file output instead of cout. The file name, cw2task1output, was just given as part of the task, in this case should I make an empty text file named cw2task1output then attach it to the resource...

HI guys, I am in the middle of a project where i have 3d printed ABS & PLA spur gears, I am looking to do gear teeth strength calculations however I am not sure how to apply the formulas. This is because of the layered structure and the infill % of the prints. Ill appreciate all help. Thank you

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...

I have four arrays of data xvalues[], yvalues[], zvalues[] and wvalues[] and I want to create, from this data, an interpolated function w = f(x,y,z). Is it easy to do this in python using first a meshgrid and then calling scipy's interpolation? e.g toy set up is something like, where wvalues...

I'm learning about imaging techniques and projection/deprojection for images of galaxies at university. The big issue there is the fact that an image is a 2D representation of a 3D object (for example a galaxy), and to learn some properties of the object you need the 3D structure. What happens...

I am trying to understand the picture below which is of a contractible and uncontractible loop in what I would call (proper name?) "rotation space", where "rotation space" is a solid ball of radius π with opposite points on the surface of the ball identified, each point of the ball representing...

Hello everyone, I am new here, and wondering if anyone would have some knowledge on a current problem I have been working on. I am trying to create time- and frequency domain 3D models of an object hanging using a spring from a fixed point within a shell. I am trying to figure out how the...

Being scratching my head for 2 days and not getting anywhere with this one. I am trying to figure out how to perform a 3D rotation described via a mix of intrinsic and extrinsic angles. Here is the problem: I have a platform in the shape of a box with sides of length lx, ly and lz. The platform...

I am having trouble following a step in a book. So we are given that $$\varphi (x) = \int \frac {d^3k}{(2\pi)^3 2\omega} [a(\textbf{k})e^{ikx} + a^*(\textbf{k})e^{-ikx}] $$ where the k in the measure is the spatial (vector) part of the four-momentum k=(##\omega##,##\textbf{k}##) and the k in the...

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.

I'm trying to wrap my head around the concept. we use 3 rotations to transfer our regular cartesian coordinates (3 x,y,z unit vectors) to other 3 unit vectors. each rotation is associated with an angle. so far I'm good. but now I saw in Landau's and Lifshitz's "mechanics" book this thing...

Hi, there's no particular question I need help on - just a few things I need clarifying. To determine the max shear stress, I know max shear stress = (max normal stress - min normal stress)/2, but are these equations true for a 3D stress state? (please look at attached image) Thank you

Homework Statement I noticed that for a line parallel to z axis the equation is (x-a)/0 = (y-b)/0 = (z-c)/k = t. Homework Equations Any 3d geometry equations The Attempt at a Solution I can't quite grasp how to visualize this, also I can't see any constant like a 2d line parallel to x-axis...

Hello, it has been quite some time since my statics class, and I am having a problem determining the reaction forces and moments in a rigid body. I have included a sketch of my problem, and I am hoping someone can help guide me to a solution. I apologize if the sketch is a bit crude.I have a...

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?