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. G

    Finding Equilibrium in a 3D System of Forces

    Homework Statement See attachment Homework Equations Let u be the angle between AC and AO and v the angle between BE and BD. Ta is the tension at point A and Tb is the tension at point B. The Attempt at a Solution Tried starting with the OAB body and got: -mg + Ta sin(u) + Tb...
  2. J

    How Does Real-d 3d and Mirrors Affect Viewing Experience?

    I saw Jurassic Park 3d today and started tinkering with the glasses after I got home. Here, I noticed that if I close one eye and look in a plane mirror that the 'lens' with the closed eye is always clear and the 'lens' with the open eye is always dark. I understand that Real-d 3d works by...
  3. R

    Understanding Circumstellar Disks: Exploring Surface Density in 3D

    Hi everyone, I'm trying to understand circumstellar disks. One term that keeps cropping up in this context is "surface density". The disks, though flattened, are still three-dimensional, so I'm confused about what "surface density" actually means. I can think of a couple of possibilities...
  4. D

    Finding volume/mass of 3D Solid

    Homework Statement The volume shown lies above a square in the (x, y) plane having corners (4, 1), (5, 1), (5, 2), and (4, 2). The remaining two surfaces are planes defined by z1 = 2x + 4y + 7 and z2 = 3x + 6y + 8. The density of this object is 880.y. Determine a) the volume of this object...
  5. J

    How to include a capacitor to an Ansoft Maxwell 3D eddy current design

    Hi experts, I wonder anyone of you have an idea on whether we can include a discrete component (specifically a capacitor) into an "Ansoft Maxwell 3D" eddy current design. Little more description: I do have a specific eddy current design with a coils. I need to add a series capacitor and...
  6. C

    Energy levels for a 3D cubical box

    Homework Statement Find the energies of the second, third, fourth, and fifth levels for the three-dimensional cubical box. Which are degenerate? Homework Equations E = h^2/8mL^2 (n^2 sub x + n^2 sub y + n^2 sub z) The Attempt at a Solution The levels would be degenerate if one of...
  7. C

    Energy levels for a 3D cubical box

    I'm trying to find the energies for n levels of a 3D cubical box. Is there a general equation for this?
  8. M

    2D becomes 3D when looked at by one eye

    When I was about 25 I noticed that a 2D photo appeared 3D when looked at through a magnifying glass. First I thought it depended on the lens, but then realized it was because I looked at the picture by just one eye - exactly as the camera lens had seen it in reality. I.e. there is much 3D...
  9. M

    Finding limits in 3D. How do you know on what line to approach?

    So say I have an arbitrary function and I want to know it's limit as x,y approaches 0. I could test what happens when the x-axis approaches 0, y-axis as it approaches 0 but there are some functions where I'm told that I also need to test what happens when y=mx approaches 0, and then y=x^2 and...
  10. Roodles01

    Calculating Emission Frequency for F-centre in a 3D Well | λ = 6.74x10^49 Hz

    Is this anywhere near correct, I have too many marks for this & it seems too easy for what I've put. What have I missed? Have I? Homework Statement An F-centre can be thought of as e- trapped in an infinite 3D well. Calculate λ of emitted e.m. radiation when transitioning from E3 to lowest...
  11. L

    Discover the Best 3D Online Calculator for Accurate Calculations

    Does anyone know of a good online 3d calculator that will actually work. Thanks.
  12. S

    What figure do these 3D vectors make?

    Homework Statement The vertices of a figure are given by A(-8, 4, -2), B(-6, 3, 5), and C(-10, 5, -9). What type of figure is ABC? Why?Homework Equations pythagorean theorem: |AB|=√(x^2+y^2+z^2)The Attempt at a Solution I first found the vector AB, BC, and CA by subtracting the components of...
  13. S

    Mathematica Mathematica: Make a 3D List from two 1D lists and a tables

    I am dealing with a set of data where I have values C(x,t) for a discrete set of x and t values. Say: x={1,5} t={1,3,7} C={{C(1,1),C(1,3),C(1,7)},{C(5,1),C(5,3),C(5,7)}}. How do I combine this to a list that looks like...
  14. G

    Drag equation using wind to create 3d graph (Again)

    Hey guys, I am back again with a drag related question, earlier I posted a thread asking how I could incorporate wind into a drag equation of sorts to create a 3d graph that shows the trajectory of a projectile. The help I received helped me add head winds and tail winds, however I am now...
  15. G

    Drag equation using wind to create 3d graph

    Hey guys, I'm new to these forums so I am unsure if this is the right place to be posting this, but here it goes. I have been working on a drag spread sheet using OpenOffice Calc to predict where a potato will land when fired from a potato gun. I have gotten pretty far along, using...
  16. B

    Finding The Limit Of A 3D Function

    Homework Statement Find the limit as X, and Y both approach 0 of (X2Y)/(X2 + Y4) Homework Equations The equation from above. The Attempt at a Solution I have been doing the technique of approaching from different lines such as y = x, or x = y, x = 0, and y = 0. All of them give...
  17. baby_1

    Some questions about 3D environment

    Hello I have some question that i confused to know them 1-what is difference between Vector and Line in 3D and 2D? 2-how can find the vertical vector on a surface or line? 3-how can find the angle between two vector or line only with their size?( i do it with Inner Product equation but...
  18. S

    Cartesian 3D Vector Plotting Points?

    Homework Statement Plot the following point: B(-2,3,5) The Attempt at a Solution If I were to plot (-2,3,5), when I make my first movement of -2, it does not move anywhere on the y-axis correct and when I am moving on my Y axis, There is no movement in the z axis?
  19. marellasunny

    Can 3D Phase Space Surfaces Arise from Differential Equations?

    Is it possible for a surface to be obtained as the solution for a system of differential equations in a 3d phase space? Almost all 3d phase plots I have observed are curves,example the Lorenz system. Is there a general formula that says that a system of n differential equations would...
  20. 1

    Homework Help 3D vectors problem solving

    Homework Help! 3D vectors problem solving! Homework Statement the vector v=(1,√2,c) makes an angle of 60° with the positive z-axis. Determine the angles that v makes with the positive x-axis and the positive y-axis. Explain how many answers there are. Homework Equations dot product...
  21. S

    Photoelectrodeposition for 3D Printing

    3D printers are receiving a lot of attention in the news these days, because they are seen to be a potential disruptive technology. However, most devices of this type are very limited in the materials they can work with, mainly fabricating models in plastics like PLA or ABS. Advanced high-end...
  22. J

    Moment around a point in 3D: Understanding Vector Calculations

    Homework Statement The threading die is screwed onto the end of the fixed pipe, which is bent through an angle of 20º. Replace the two forces by an equivalent force at O and a couple M. Find M and calculate the magnitude M' of the moment which tends to screw the pipe into the fixed block about...
  23. F

    Exploring 3D Angles: A New Way to Represent Intersecting Planes?

    i would like to know if the 'angle' between let's say the walls of a room (ie. the intersection of 3 planes all perpendicular to each other) can be represented in mathematical terms, but as a kind of 3D angle- that is to say not as a combination of 2D angles but as an altogether new form of...
  24. J

    Partial derivatives of 3D rotation vectors

    I am utilitizing rotation vectors (or SORA rotations if you care to call them that) as a means of splitting 3D rotations into three scalar orthogonal variables which are impervious to gimbal lock. (see SO(3)) These variables are exposed to a least-squares optimization algorithm which...
  25. Sneakatone

    Questions on 3d displacement vectors

    A room measures 4 m in the x direction, 5 m in the y direction , and 3 m in the z direction. A lizard crawls along the walls from one corner of the room to the diametrically opposite corner. If the starting point is the origin of coordinates, what is the displacement vector in terms of unit...
  26. S

    3D tension problem (static equilibrium)

    Homework Statement A block of weight 50N is hung by 3 cables from the ceiling. Each rope ZA, ZB, ZC converges at Z so that they form a tetrahedron. (ZA=ZB=ZC=AB=BC=CA). Find the magnitude of the tension of each cable. a=0 tetrahedron symmetryHomework Equations F=mgThe Attempt at a Solution I...
  27. O

    Half-edge data structure in 3D?

    Hello Everyone I'm currently working on a unstructured quadrilateral mesh for a discontinuous galerkin free surface flow model. I use the half-edge data structure in the two dimensional code. Does something like a half-edge or "half-face" three dimensional data structure exist. Otherwise...
  28. K

    MATLAB How to Create a 3D Plot in Matlab for Matrix Visualization?

    Hi everyone, I'm working on a project where I need to produce a 3D plot for matrix using Matlab. The plot must comprise of both alpha and beta in 3D. Alpha, A is a 320 x 333 x 4 matrix, where each individual layer (i.e. A(320,333,i) for i = 1:4) represents one image's angles. The beta matrix...
  29. F

    Projected Separation and 3D Distance Problem (Code Included)

    Hi all, I've written code that takes J2000 equatorial coordinates for 2 objects and calculates (1) the projected separation of between object 1 and object 2 at the distance of object 1, and the Euclidean (3D) distance between objects 1 and 2. The projected separations should be <= the Euclidean...
  30. O

    Calculating Magnetic Flux in 3D

    Hi everybody, first time poster here. I am working on calculating the force of magnets in a 3 dimensional space. I have found a formula for the magnetic flux density at a distance z from the magnet face at this link http://www.magneticsolutions.com.au/magnet-formula.html, under Flux density at...
  31. W

    Projectile Motion in 3D space (Writing an Aimbot)

    Alright, so, I am writing an aimbot for a popular game, and I need a bit of help with calculating the correct pitch angle for the player. The weapon is a bow, so the arrows are affected by gravity. I am trying to find the pitch angle that accounts for gravity and distance from the Entity you are...
  32. L

    Finding the reactions at the supports, 3D model

    Homework Statement Hi. See attached, I need to determine the forces in all members. Homework Equations Sum of forces in X, Y & Z all equal 0. Sum of moments in X, Y & Z all equal 0. The Attempt at a Solution I've drawn the reactions at each support, A, B and C in my 2nd attached...
  33. J

    Ansoft Maxwell 3d Closely coupled inductor

    Hello! I am having an issue with getting any graphs on inductance or induced voltage. In the attached circuit: What I have is a 28Vac source w/ 400hz and 2 coils (R=18.6ohm each) that are connected with a common. In the model: I have a core in the center that will be able to move up...
  34. C

    Application of gradient vector in 3D

    Homework Statement The temperature ##T## in a region of Cartesian ##(x,y,z)-## space is given by $$T(x,y,z) = (4 + 3x^2 + 2y^2 + z^2)^{10},$$ and a fly is intially at the point ##(-5,6,7)##. Find a vector parametric representation for the curve which the fly should move in order to ensure...
  35. L

    Find orthogonal vector to current vector in 3D

    Hi, In 2D I know a simple answer: vector (a,b) is orthogonal to vector (-b,a) Is there anyway similar to that to find an orthogonal vector in 3D?
  36. D

    N spin 1/2 particles in 3D harmonic oscillator potential

    Homework Statement The 3-dimensional harmonic oscillator potential holds N identical non-reacting spin 1/2 particles a)How many particles are needed to fill the low lying states through E=(3+3/2)\bar{h}ω b)What is the total energy of the system c)what is the fermi energyHomework Equations...
  37. N

    Calc III: Shortest Distance in 3D Problem

    Calculus III, find shortest distance, 3 dimension problem? check my answer please?? What is the shortest distance from the point P = (0, 1, 2) to the line given by l(t) = (1+t, 2-2t, 3+3t)? use distance formula d = sqrt ((x-0)^(2) + (y-1)^(2) + (z-2)^(2)) d^(2) = ((x)^(2) + (y-1)^(2) +...
  38. S

    How to use a 4x4 Matrix to translate a point in 3D space

    Hello, apologies in advance if my questions seem rather ignorant. I'm trying my best (and struggling) to understand the topic, but my background in math is weak, and i need the math for artistic purposes. I want to iteratively move and rotate a point in 3D space (move, rotate, move, rotate...)...
  39. S

    Understanding 3D Planes & Hyperplanes: Intuition & Practical Explanation

    In the following two problems I am trying to get a deeper intuition of, the plane has 3 variables and is 3 dimensional and the hyperplane has four variables and is 3 dimensional as well. Can someone please show me why, practically, in the context of these problems? Question with hyperplane...
  40. X

    3d dynamics rotation/inertial formula question

    Homework Statement I just saw the equation R'=RΩ (where ' is dot, or the derivative) in my notes (unorganized obviously), and can't remember what it stands for (rotation matrices?). Can somebody please tell me what this equations means thanks. I know R is some position vector and Ω is the...
  41. X

    Understanding 3D Rigid Body Dynamics Equations: R=R'Ω Explained

    Homework Statement I just saw the equation R=R'Ω (where ' is dot, or the derivative) in my notes (unorganized obviously), and can't remember what it stands for (rotation matrices?). Can somebody please tell me what this equations means thanks. I know R is some position vector and Ω is the...
  42. U

    Solar System's orbit around galaxy, a concise 3D description?

    Hello, this is my first topic/question, thanks for reading thus far... It is very easy to find explanations about the general path that the solar system takes when it orbits the center of our galaxy, when viewed in 2D from above, a circle around the center some distance away from that center...
  43. S

    Does rotation of a 3d volume about a 2d plane create gravity?

    Hello, If a rotation of a 2-d disk about a 1-d line can produce centrifugal gravity, is it right to infer that rotation of a 3-d volume about a 2-d plane would create gravity, observable in the 3-d volume? It is confusing to think about the direction of this gravity, if it exists...
  44. E

    3D Transport and Adsorption model on Comsol

    Hi everyone, I'm trying to design a simple model by using Comsol Multiphysics. I set an inlet concentration of a species "cp" that will be adsorbed to a circular surface located at the center of the microfluidic cell (I named the concentration of adsorbed protein "cpl" ). I used laminar flow...
  45. D

    Model the relationship between 3d points given two reference points

    Homework Statement Trying to figure out how to model the relationship between two 3D points, A and B. Both points have visibility to 2 common reference points, C and D. Bearing and angle readings are available from both A and B to the reference points C and D. The reference points C and D are...
  46. C

    Create 3d function with a set of points

    I'm creating a computer program and I need to see what's most efficient. I need another program [lol] that I can input 3d points in and have it create the function. the points are this v e t 100 500 3...
  47. D

    Find coordonates of a point relative to a second plane in 3D

    In a 3D plane, there is a point with it's X,Y and Z coordonates known and a second 3D plane within the first plane with it's origins X,Y and Z coordonates relative to the parent plane origin. How do I find the X,Y and Z coordonates of that point relative to the origin of the second 3D plane...
  48. J

    Variational Principle of 3D symmetric harmonic oscillator

    Homework Statement Use the following trial function: \Psi=e^{-(\alpha)r} to estimate the ground state energy of the central potential: V(r)=(\frac{1}{2})m(\omega^{2})r^{2} The Attempt at a Solution Normalizing the trial wave function (separating the radial and spherical part)...
  49. C

    Circulation of a 3d vector field

    Homework Statement consider the vector field v(x,y,z)=(-h(z)y,h(z)x,g(z)) wherer h:R->R and g:R—>R are differentiable .Let C be a closed curve in the horizontal plane z=z0.show that the circulation of v around C depends only on the area of the reion enclosed by C in the given plane and h(Z0)...
  50. L

    Balancing a 3d weight vs lift system

    Hi I'm trying to balance any 3d system with various fixed weights by selecting the correct lift forces for points of lift an example system would be the following shape ( view from above , think a plane missing the right wing) where X is a point of weight and L is a lift point (also has weight)...
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