physics

问题 I'm having trouble wrapping my mind around how to calculate the normal for a moving circle in a 2d space. I've gotten as far as that I'm suppose to calculate the Normal of the Velocity(Directional Speed) of the object, but that's where my college algebra mind over-heats, any I'm working with to 2d Circles that I have the centerpoint, radius, velocity, and position. Ultimately I'm wanting to use the Vector2.Reflect Method to get a bit more realistic physics out of this exercise. thanks ahead

问题 I'm working in a project that involves gyroscopes... I'm using Arduino and an ITG 3200 to read the data from the gyroscope. I get 3 values in deg/s for each axis (x,y,z). My question is: How can I know the actual (physical) position or direction of the device (let's say an airplane). There has to be a math formula or something like that. 回答1: Using only the gyroscope signal (which you have to integrate numerically), you'll eventually run into trouble, due to drift. What's normally done is

问题 I want to ask about jelly physics ( http://www.youtube.com/watch?v=I74rJFB_W1k ), where I can find some good place to start making things like that ? I want to make simulation of cars crash and I want use this jelly physics, but I can't find a lot about them. I don't want use existing physics engine, I want write my own :) 回答1: Something like what you see in the video you linked to could be accomplished with a mass-spring system. However, as you vary the number of masses and springs, keeping

问题 Is there an alternative to making educational Java applets for physics simulations like projectile motion, gravity, etc? 回答1: If you want it to run in a browser, you could use PyJamas - which is a Python-to-Javascript compiler and set of tools. I'm not sure how well it is maintained these days, though. 回答2: In this day and age, you might look to the HTML 5 canvas & JS. 回答3: While I'm all for the "HTML5 & JS", you can consider Jython and simply write a Java Applet in Python (2.2.3, but...)

问题 I am using bodyWithPolygonFromPath to define the volume of the physicsbody, and used http://dazchong.com/spritekit/ to get the paths required. But the path does not seem correct and I wish to see the borderline of the physicsbody path to see if the shape is correct. Is there any way to see the physicsbody's volume outline? I tried the following code, but it doesn't work. ship = [SKSpriteNode spriteNodeWithImageNamed:@"Spaceship"]; CGFloat offsetX = ship.frame.size.width * ship.anchorPoint.x;

问题 i have a question about moving a Box2D body to a specific position without using this for example. body->SetTransform(targetVector,body->GetAngle()) I have some code which works for applyForce (here): const float destinationControl = 0.3f; b2Vec2 missilePosition = _physicalBody->GetPosition(); b2Vec2 diff = targetPosition - missilePosition; float dist = diff.Length(); if (dist > 0) { // compute the aiming direction b2Vec2 direction = b2Vec2(diff.x / dist, diff.y / dist); // get the current

问题 I recently asked about trying to optimise a Python loop for a scientific application, and received an excellent, smart way of recoding it within NumPy which reduced execution time by a factor of around 100 for me! However, calculation of the B value is actually nested within a few other loops, because it is evaluated at a regular grid of positions. Is there a similarly smart NumPy rewrite to shave time off this procedure? I suspect the performance gain for this part would be less marked, and

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Need to plot graph the intensity versus wavelength for the spectrum. Also, me need to determine the wavelengths from the graph (the image below): With which program I can do this? I searched in Google program, but they all work with video (example theremino spectrometer)?. I need to work the image. 回答1: That's

问题 I have a Swift / SpriteKit game in which a whole bunch of sprites have physics bodies to detect collision with the player - but otherwise they are not supposed to move. My issue is that as soon as I add a physics body, the sprite appears to move fractionally. More specifically its position changes by a small fraction (like 0.0003). Initially such a small change does not matter, but it keeps changing like this until the sprite actually moves onscreen and messes up the game. To narrow it down I

问题 I've done a lot with box2d in c++, and am giving C# a try. It looks like Farseer is generally used in place of Box2D (I'm aware of Box2DXNA, but it seems a little outdated.) So, Farseer is what I've been using. When I was using C++ and Box2D, everyone always advised against using a 1pixel/meter ratio (For what reason, I don't know,) and usually suggested using somewhere around 30pixels/meter. As I've been researching Farseer, I've seen a lot of conflicting statements. Some say to use 1pixel