Optical Illusions

Question

For those looking for ideas, some nice simple but effective programs could be made to show some optical illusions. 

Here's a couple to start with:

Import PVC930 and CDV606

Answer 1

Wow!!  This is awesome.  Got more?  Mind if I blog about this?

Answer 2

There are loads to copy on the net, mostly just a few lines of SB code, a couple more I just did: FMW356 CNR593 TTR706.  Sure, use them.

And another (ZPJ441), the blue and green are both the same colour (Cyan).

Answer 3

Ouch my eyes!  You've warped pixels, nice.  Wow, I can't believe the blue=green one, freaky, any idea why that works?  I'm not sure what TTR706 (spinning pink dot) is supposed to do.

Answer 4

bigdaddyo,

The spinning dot, if you look at the centre cross, it appears that a green 'ghost' dot appears in the space.  If the original dots are yellow, then the ghost dots appear blue. 

Also, if you stare at it for 30sec+, some of the pink dots around the perimeter seem to disappear for a second or two, leaving a gap of several dots.

Answer 5

The spinning dot, if you look at the centre cross, it appears that a green 'ghost' dot appears in the space.

That is so cool.

Answer 6

Yeah sure, I know that, the best illusion.

and the ZPJ441 is really cool !

see XLG372 - description inside, not so cool, but my first.

Answer 7

Vitexikora,

Simple and very effective.

Answer 8

NEW !!!

All illusions seven-in-one !

Import: CJR855

-requires fremy extension

-personally on my computer, (4) is not working properly. I don´t no why, the code of the animation works only if it stands "alone".

-please tell me about some mistakes with english.

Answer 9

Vitexikora,

You have stumbled over an important issue with SmallBasic which may be a bug.  It took a bit of playing to work this out!

Basically you cannot start a subroutine that has moving shapes from inside an event subroutine.

The following fails to work properly:

GraphicsWindow.KeyDown=OnKeyDown

Sub OnKeyDown
  illusion4()
EndSub

The following works:

GraphicsWindow.KeyDown=OnKeyDown

start = 0
While ("True")
  If (start = 1) Then
    illusion4()
    start = 0
  EndIf
  Program.Delay(100)
EndWhile

Sub OnKeyDown
  start = 1
EndSub

This seems to also be the case for the Fremy Control button events.

So, you need to set a flag from the event call, and use this flag to control the program from a Main Loop. 

This is a recurring theme - do all the main work in the main program loop - and just use events to set control flag variables . 

This is extended here to do not call subroutines that do any animation (work) directly from an event .

 

 

Answer 10

Ok, thanks, I will try to repair it.

And the event subroutines, you described me should be the main problem of my last programs....

Answer 11

Yes, I think this is the only problem.

Answer 12

This thread is featured in the Small Basic blog.

http://blogs.msdn.com/smallbasic/archive/2010/03/29/optical-illusions.aspx

 

Answer 13

There are loads of examples of optical illusions and descriptions why/how they work on the net, just google for them, then have a go reproducing them with SmallBasic - most are fairly straight forward to code.

Answer 14

And another (ZPJ441), the blue and green are both the same colour (Cyan).

Awesome.  I wanted to "prove" to my eyes that the colors were the same, and I wanted to monkey about with the column size, so I made http://smallbasic.com/smallbasic.com/program/?KMT643 (edited to be a link instead of just the letters).

I cut it down to only 3 rows and made the first part of the bottom row and the latter half of the second row extend into the second row (by making the second row those colors in those spots).  It uses an initially set columnwidth and columnheight to monkey about with the columnsize, so after importing KMT643 on your computer, you can fiddle around with the column sizes (first two variables) each time you run the program.