The smoothness of motion depends on two things...the framerate (how fast the picture is updated) and the sprite speed. If you have a slow moving sprite, the framerate can be pretty slow and it will still look smooth. If you have a fast-moving sprite, it's important to keep the framerate high.
So how do you make your motion look smooth? Either keep the sprites moving fairly slowly or make sure your project can update the picture pretty fast. Or both.
That's the generic answer. If you have a specific problem with a project, maybe you could share it to the web and we could recommend strategies for smoother motion.
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You can use the motion block 'glide' for movies
And you can use this script:
When Green Flag Clicked:
Forever:
If Up arrow key pressed, change y by (#)
If Down arrow key pressed, change y by (-#)
If Left arrow key pressed, change x by (-#)
If Right arrow key pressed, change x by (#)
'#' is whatever number you want it to be.
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