I'm trying to create a guitar hero type game and I'm working on a horizontal metronome where a dot crosses a certain vertical line means to play a note.
The metronome starts when the note is 5 seconds from being played then moves across and finally hits the vertical line. Are there any algorithms for making the dot move at the correct speed so it hits the line in exactly 5 seconds.
Also the image movement is very choppy. Is there any way to smooth the movement of the image across the view?
I would appreciate any feedback, thanks.
High-school physics - velocity = distance / time
Also, you probably don't really want "5 seconds" as your fixed preparation time for every song. 1 or 2 bars (at the song's tempo) would be better.
Related
I need to create 2 animations,
one is of an object going from point A to point B at a constant velocity.
the other is of an object starting from point A but with a gradually decreasing velocity as it reaches point B until it comes to a stop.
I tried decreasing the animation speed every second to achieve this result with no luck.
Any ideas?
As you may have noticed when you work with animation in Unity there is no such thing as changing the velocity of an object. What you need to do is give your object an Animator and create a new Animation.
Then on the animation timeline press the red dot (record button) and then place your object on point A.
Next, on the time line you want to select the exact second that you want your object to come to a stop and after that move the object on point B.
Now, the more seconds there are in between the 2 keys, the more time it's going to take for the object to travel.
To make it gradually slower instead of it just travelling slowly:
On the animation panel you will see 2 tabs. Dopesheet and Curves. Hit Curves and play around with them till you have a satisfing result.
Documentation on using Curves
Usually in 2D physics engines like JBox2D, if the user wanted to make a simulation run in "slow motion", you would just decrease the value by which the simulated world iterates by, for example normal movement at 60fps, the step would be 1/60 if the physics world is stepped forward every frame.
But for the SKPhysics class in the sprite kit in xcode 6 using swift, I only see the property called ".speed" which when I decreased, only led to a jittery mess, that updated the physics bodies once every 10 frames.
Is there a specific property, or trick maybe to get the SKPhysics world to iterate forward in time by smaller increments without gross glitchy movements?
The only way to slow down the simulation in sprite kit is to use the physicsWorld.speed element.
But if you are trying to change only one or two sprite speeds, try the velocity element of the sprite:
node.physicsBody.velocity = x
you can directly change the velocity(speed) of your node or sprite through its physicsBody.
Hope it helps :)
How to measure the force by which Two rigid Bodies collide and in the reaction add force to other object in opposite direction. For example in the cricket game how the force is measured b/w bat and ball . If player blocks it add a min force to the ball and if he plays the shot he ball goes too far for a four or a six. I will say that just simple addforce() component will not work. It will just apply the force every time when it hits the bat doesn't matter it is blocked or a shot played.
I got a field in unity3d that has some depressions in it (like small holes). The field's slope always leads towards the nearest depression.
A sphere is dropped at random somewhere in the field, rolls around a bit until it stops in one of the depressions.
The problem is, this is taking too long. It could roll around for 5-10 seconds until it stops. I'd like to stop faster.
Any ideas how I can achieve this?
Edit: The main issue is when the ball is next to the depression, but it has speed that is 90 degrees from the hole, then it starts going in circles and takes a while to stop.
Ok, after getting some advice in the comments, and experimenting, this is the way I solved it:
Apply a small measure of strength towards the depression
If the current velocity is more than 30 degrees away from the center of the depression, slow the ball (apply strength in the opposite direction of the velocity)
IF the ball gets very near the center of the depression, stop it and place it in the center
Thanks for all the tips. If anyone comes up with a better way, I'm still open to suggestions.
The game was created by support cocos2d 0.99.5 and Box2d.
Iphone SDK 4.3
We have a character. When a character moves quickly, it looks blurred (fuzzy // unfocused). On a simulator and on device (iPhone 3G).
To move a character using mouseJoint (dampingRatio = 0 // frequencyHz = -1).
In the screenshot image clearly. link
The character is focused. The screenshot not transfer problems.
All the time 60 fps.
Tried params:
use kCCDirectorProjection2D // 3D
alies // antialies to texture params
CC_COCOSNODE_RENDER_SUBPIXEL 1 and 0
Video sample: link
How to get a clear image of the character during the move?
I also had a problem like this and fixed it by changing this line in ccConfig.h:
#define CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL 0
to
#define CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL 1
This is the comment for this define, maybe it helps someone.
/** #def CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL
If enabled, the texture coordinates will be calculated by using this formula:
- texCoord.left = (rect.origin.x*2+1) / (texture.wide*2);
- texCoord.right = texCoord.left + (rect.size.width*2-2)/(texture.wide*2);
The same for bottom and top.
This formula prevents artifacts by using 99% of the texture.
The "correct" way to prevent artifacts is by using the spritesheet-artifact-fixer.py or a similar tool.
Affected nodes:
- CCSprite / CCSpriteBatchNode and subclasses: CCLabelBMFont, CCTMXTiledMap
- CCLabelAtlas
- CCQuadParticleSystem
- CCTileMap
To enabled set it to 1. Disabled by default.
#since v0.99.5
*/
I am pretty sure that what you are describing is an optical illusion. LCDs, especially lower-quality LCDs, have a finite response time. If this response time is too slow, it can cause ghosting, i.e. the moving object looks smeared. Basically what's happening is the previous frame's (or several frames') pixels take a long time to actually "turn off" and you see fainter versions of your sprite left behind as it moves.
With regards to your comment:
For the experiment, I took a pencil and put it to a sheet of paper
began to move quickly. Eyes see a pencil in focus, then problem is not
an optical effect, a code problems
Looking at a moving object in the real world is not the same as looking at a moving object on the screen, with or without a poor display response time. The real-world object moves continuously, but the screen object moves in discrete steps. Your eye can follow the pencil exactly and keep the image sharp on your retina. If you follow a screen image, however, your eye moves smoothly, while the screen image "jumps" from place to place. This can cause a "juddering" effect for sufficiently fast-moving objects, even at high framerates. If 60fps is still juddery, there is basically no way around this; it is a limitation of current technology.