Category Archives: tutorial

I’m really enjoying giving a control panel of sorts to the end user and letting them control the physics rules of their canvas. Let’s add more motion to it by applying a jitter to the velocity of each dot. This is similar to earlier, when we first started animating by applying a random number to [...]

I always want to give the end user (at least some) control of how they view and interact with data. Earlier we gave users control over gravity. Here let’s give them control over the canvas edges. Rather than having our dots bounce on the edges of the canvas, lets have them wrap across to the [...]

Earlier we worked on making all the dots draggable, but what’s better than simply dragging dots? Let’s set up a way to throw the dots! Now as we drag it we record the positions and use that to calculate a new velocity. Then when a dot is dropped, it will have a trajectory to follow [...]

Here is an update to allow the end user to create more dots. A good way to do that is to just let users click on the canvas, and if they click a dot, drag it, if they don’t click a dot, create a new dot at the point of click. I moved the dot [...]

Now that we have gravity we’re really seeing some natural looking movement. Yet, it’s still missing something. In the real world we have friction or drag (or even air resistance) on everything. Without this friction it’s like these balls are moving in space. Even when they bounce on the walls they don’t loose any velocity, [...]

Adding gravity! Here we’ve adjusting the y velocity in every frame with the force of gravity. It’s fun to play with options and see how they are affecting the animation and the physics, so I’ve also got a checkbox that will toggle gravity to either a vlaue of 2 or 0. interactive physics animations via [...]

Well, the last iteration was fun, but the animation went so quick. Now we’re going to do something to contain these dots in our canvas. Let’s have them bounce off the edges of the canvas. We’ll multiply the velocity by a bounce variable. This will reverse the direction the dot is going. We’ll have a [...]

Now that we have our framework for animation we can make things a bit more fluid. Let’s use a velocity to update the positions or coordinates of each dot rather than just throwing random numbers at them. We can then adjust the velocity or rate of movement and it will be a much more natural [...]

Here’s a quick and easy update. I tend to think of frames in animation and rarely do I think of milliseconds. I’m going to make a var called fps and it will be used to calculate our animation rate. interactive physics animations via javascript & canvas | 09. $(function () {     var canvas, [...]