fieldofview | 易学教程

Maximize zoom distance to fit 2 objects

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问题 Objective: Move the camera position ONLY on the Z axis so the frustrum fit 2 objects. Conditions: One of the objects will be allways aligned with the camera X position Camera is set on perspective mode , not ortographic. the 2 spheres have no parent The result seen in ortographic mode from top-view should look like this: What I've done so far: Using trigonometry this can be seen it as: Knowing that, the objective is to find the Adjacent side, which will be the distance between the camera and

How to calculate FOV?

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问题 Initial Context I am developping an augmented reality application location based and I need to get the field of view [FOV] (I just update the value when the orientation change, so I am looking for a method which can get this value when I call it) The goal is to make a "degree ruler" relevant to reality like the following: I am already using AVCaptureSession to display camera stream ; and a path coupled with a CAShapeLayer to draw the ruler. This is working pretty good, but now I have to use

How to plot the field of view of an Earth-Observation satellite when close to the poles using basemap?

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问题 I am trying to draw the maximum (theoretical) field of view of a satellite along its orbit. I am using Basemap, on which I want to plot different positions along the orbit (with scatter), and I would like to add the whole field of view using the tissot method (or equivalent). The code below works fine until the latitude reaches about 75 degrees North, on a 300km altitude orbit. Beyond which the code outputs a ValueError: "ValueError: undefined inverse geodesic (may be an antipodal point)"

Relation between horizontal, vertical and diagonal Field-of-View

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问题 Is there a mathematical relation between those values? If I know hFOV and vFOV can I calculate the diagonal FOV without involving other values like focal lengths etc? My first thought was to use Pythagorean theorem but maybe it's wrong. 回答1: The physical quantities of interest are the sensor size and the focal length. The latter, in the pinhole camera model, is the the distance between the camera center and the image plane. Therefore, if you denote with f the focal length (in mm), W and H

iPhone SDK - get/calculate camera field of view (FOV) (Augmented Reality)

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问题 Is there a way to find out or calculate the field of view (FOV) an iPhone camera has through calls to the APIs? Or is it something you have to physically and manually find out for yourself? If it cannot be fetched or calculated with the APIs, but instead has to be hard-coded into an app, then what's the best way to find out what kind of device an app is running on? Different devices have different FOV (iPhone 4 has larger FOV than previous versions.) Also, how big are the FOVs of each device,

three.js - check if object is still in view of the camera

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问题 When working with a 2d canvas, if you want to check if something is no longer "on screen" you simply do something like this: if( pos.x > window.innerWidth || pos.x < 0 || pos.y > window.innerHeight || pos.y < 0 ) { // has left the screen } How would I check to see if something is still "on screen" ( in view of the camera ) in a three.js scene? 回答1: Instead of check 2d canvas, you can check a 3d point is in frustum or not. camera.updateMatrix(); camera.updateMatrixWorld(); var frustum = new

How to calculate FOV?

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Initial Context I am developping an augmented reality application location based and I need to get the field of view [FOV] (I just update the value when the orientation change, so I am looking for a method which can get this value when I call it) The goal is to make a "degree ruler" relevant to reality like the following: I am already using AVCaptureSession to display camera stream ; and a path coupled with a CAShapeLayer to draw the ruler. This is working pretty good, but now I have to use Field of view value to place my element in the right place (choose the right space between 160° and 170°