I'm new to JavaFX and encountered a problem with the rotating animation while trying to write a Rubik's cube solving program.
I know JavaFX provides some classes for the animation ,but instead of using them, I wanted to try my own approach initially.
Following is the rough idea of my code :
for(90 times)
{
cube.setRotate(cube.getRotate() + 1);
try{Thread.sleep(100);}
catch{InterruptedException e) {Thread.currentThread().interrupt();}
}
By rotating the cube only one degree at a time and using time delay and loop appropriately, I expected to see something similar to rotating animation.
But the result I get is that the cube in the screen doesn't change with each setRotate() in the for loop, it only changes after the loop is over and therefore it changes 90 degrees at one time after 90*100 milliseconds.
I'm wondering if there is a method that can refresh the output in the screen each time using the setRotate() method.
Why do you want to avoid the mechanisms which are designed to make animations. Don't you think there is a reason that they exist?
With your code you are blocking the JavaFX application thread and the resulting behaviour is described in all documents dealing with this issue.
Related
I’m working on a complex project in threejs.
Trying to cut the corner:
I have to load an obj, create some pivot point to use as parent of the mesh inside this obj, let the user move and rotate the pivots.
It takes somewhere about 10 to 15 seconds to load due to its complexity.
My problem is that it is working flawlessly if I load the page and don’t change the focus, but if I change the browser tab or collapse the browser window I got a very specific problem:
geometry.computeBoundingBox() gives different results.
Is there someone who can help me figure out what’s happening?
To help you better understand the situation: at loading time I have to rotate the obj to -90° on the X axis (inverting Y and Z as a consequence); I think it’s relevant because the boundingBox calculation somehow inverts Y and Z and changes its min and max also, but as I said only if I switch tab or collapse the browser.
p.s. No matter the OS nor the browser. It’s a super consistent bug
Ok, I somehow solved the issue, but take it with a grain of salt:
the problem can be tracked back to the execution stack of javascript:
the first function computes the bounding box, the second uses this computation, but if the first function is somehow slower to execute, the second could not have what it needs.
What I did is to force javascript to execute functions in a given order and only when the previous is finished.
The problem occurred only when changing the tab because browsers optimize resources of non visible tabs, but the code I wrote was anyway too much entropic to work properly.
I hope what I found will be understandable and useful to someone else in future.
This answer provides a nice way to make smooth animations in SciLab. I now have to write a simulation of a body attached to two strings (and therefore its movement regarding some additional forces).
The code in the link works well to render movement of a single point and, unfortunately, I didn't manage to make an animation of a point + two lines using this method. If someone is curious, I tried this code to do it:
frametime=(tk-t0)/Nt//defining the waitnig time
plot(Y(1,1),Y(2,1),"o")//plotting the point
plot([0;Y(1,1)],[0;Y(2,1)],style=1)
plot([D;Y(1,1)],[0;Y(2,1)],style=1)//plotting the two initial lines
h1_compound = gce();
h_point=h1_compound.children
h_point.mark_size = 20;
h_point.mark_background = 2;
h_line1=h_compound.children
h_line2=h_compound.children
//h_axes = gca();
//h_axes.data_bounds = [0,-1;10,1];
realtimeinit(frametime);
for i=1:Nt//my vectors have Nt points
realtime(i);//wait "frametime" seconds before drawing the new position
h_point.data=[Y(1,i),Y(2,i)];
h_line1.data=[[0;Y(1,i)],[0;Y(2,i)]]
h_line2.data=[[D;Y(1,i)],[0;Y(2,i)]]
end
The question is: is there any way to make an animation of three shapes without making axes blink (as it is with the window refreshment) or other wierd stuff?
Since you didn't create a MCVE I can't reproduce your exact problem. But you may try to add drawlater(); before, and drawnow(); after your data modification to see if it does help with blinking or not.
Or you may get much better looking result by saving your plots in every round with xs2gif and assemble the animation with another gifmaker progam (there are free online sites to do this, however with some limitations). If you need to present your result, you should do this step anyway.
I am making a drawing on NSView using a timer that is set to update every .02 seconds. On update some physical simulation makes a step, and then Canvas!.needsDisplay = true. It works when app is in foreground (usually), but when some lags happen, simulation progresses forward despite the fact that view hasn't reflected it yet. How do I pause the timer during these times to make simulation happen only when NSView can show it? I do not want to call step_over from inside drawRect, cause it seems like a bad idea, because then it would be harder to stop the simulation.
Generally this kind of update should be done the other way around, by letting the display ask you for frames as it can display them. This is done with a CADisplayLink CVDisplayLink (this is Mac; CADisplayLink is iOS). Configure it with a method you want to be called when a frame can be drawn.
Generally you do want your simulation to keep moving forward, even if it means dropping frames occasionally. For that, you check the timestamp and use that to work out what time to use for your new frame. But if you only want to move forward when the display can show it, then just update once per call.
Note that generating at 50fps is often going to mismatch the system that's trying to draw at 60fps, so you're going to wind up missing frames occasionally. That's one of several reasons not to try to push drawing with a timer.
See also Alternative of CADisplayLink for Mac OS X. Note that trying to draw at 50fps with Core Graphics usually isn't going to give good results in any case. The right tool here in OS X is Core Animation (or SpriteKit for games on 10.10, or OpenGL for more advanced high-speed rendering). You can do very basic animations with an NSTimer (and we did for years before Core Animation came along), but it's not really a tool for complex drawing.
This is the first time I've ever posted in a forum, so thanks in advance for anyone who takes the time to read/answer this question.
What I'm trying to create is basically a flipping coin animation, which starts off turning very fast and then slows down to stop with a (randomly generated) side facing upwards after about 8 seconds.
I've done the animation of a complete flip, which lasts about half a second, and made it in to a movieclip... now I'm stuck!
Any ideas how I might go about doing this in actionscript3?
The fastest way around this would be to use some very basic actionscript. First, create 2 animations (One heads, one tails). Now, you only need a single frame for this and don't need to place the movieclips on the stage. Use the following or similar code:
var whichSide:int = 0;
var coin1:coinAnimation1 = new coinAnimation1();
var coin2:coinAnimation2 = new coinAnimation2();
whichSide = math.Round(math.Random(1));
if(whichSide == 1)
{
addChild(coin1);
}
else
{
addChild(coin2);
}
Just don't forget to right click the movieclip and export for actionscript, giving the movieclips the class of: coinAnimation1 and coinAnimation2.
Hope this helps.
I've accomplished such animation on ´Keyframes´ using the Tweener class. You can easily tween on the keyframe parameter with specific transition...
Basic example:
Tweener.addTween(myMovieClip, {_frame:10, time:2.5});
More information about Tweener here
I'm writing a video annotation application with Qt4 in which users need to be able to seek to various points in a video, putting markers on various objects and then setting keypoints for those markers so that they stay on the objects in the video as they move around. QGraphicsItemAnimation seems like a great place to start for these markers, however they need to be able to appear and disappear at specific times, which I can't figure out how to do with the QGraphicsItemAnimation. I could set the scale at 0 to make the objects disappear, but that seems like a pretty hacky solution, and I'm guessing that the paint engine would still waste cpu cycles trying to draw those invisible objects. Does anyone have a better solution than this? I'm using Qt 4.5.3 right now, but I'm willing to upgrade to 4.6 if it makes things easier. Thanks!!
It seems like the functionality you want of showing/hiding QGraphicsItem objects is beyond the scope of the simple "tweening" that the animation class performs. It is only for one object at a time, and any appearance or disappearance you have to write yourself.
You still might get some mileage out of QGraphicsItemAnimation (although the fact that it uses its own timer instead of being locked to the frame clock of your video is a little dodgy).
Neglecting "seeking" for a moment, there is a QTimeLine::finished() signal. If you let the end of an annotation's active animation timeline represent the point where you want it to disappear, you can trigger QGraphicsItem::hide() at that point. When it comes time to turn it back on, you would construct a new QGraphicsItemAnimation (based on the next run of keyframe data for that object) and call QGraphicsItem::show().
Note that one of the headlining features of Qt 4.6 is the QtAnimation framework, which is more sophisticated but also rather complex. I've not used it yet, but looking over the examples it seems like you might be able to "animate" a visibility or opacity property.