* Normally Scratch pauses each time it reaches the end of a repeat loop and updates the screen. * But Scratch does not pause to update the screen inside "run without screen refresh" custom blocks. - Press <1> to draw each pattern fast as each is drawn in a "run without screen refresh" custom block. - Press <2> to draw each pattern line by line as drawing does NOT use "run without screen refresh". Press <3> to draw all the patterns together from inside a super "run without screen refresh" custom block.
You should use "run without screen refresh" custom blocks in your projects whenever you want to do a lot of drawing before the screen is updated. See this tutorial: https://scratch.mit.edu/discuss/post/3680406/ Note: A custom block with "run without screen refresh" may call other custom blocks from its script. Then Scratch will make those custom block also run without screen refresh!
