showing trace when animation on

FangShin shared this question 1 month ago

Answered

Hi.

I am drawing a sun-moon-earth locus. I have almost finished them all. At last step, the moon trace doesn't show up when animation on.

But if I pull the variable alpha myself, the trace is shown. So I am confused now, what problem do I meet?? 😭

Thanks

Files: sunmoonearth2.ggb

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Best Answer

rami ● 1 month ago

set the animation to run in the lower left corner of the graphic

right click on alpha, set animation to false

In the Algebra window right click on A, set animation to false

In the Algebra window right click on F, set animation to false

Then the trace works when alpha is animated.

(but I do not know why, note: I am 99% sure that the app does not contain any scripts).

Comments (7)

FangShin ● 1 month ago

File is uploaded.

Thanks in advance.

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rami ● 1 month ago ●

set the animation to run in the lower left corner of the graphic

right click on alpha, set animation to false

In the Algebra window right click on A, set animation to false

In the Algebra window right click on F, set animation to false

Then the trace works when alpha is animated.

(but I do not know why, note: I am 99% sure that the app does not contain any scripts).

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FangShin ● 1 month ago

Thanks, it really works !

but my sun is not rotating in these steps 😂 , thanks by the way !

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rami ● 1 month ago

Now I understand why:

Instead of the method in my last post.: Set Background Image of pic1 to OFF and set the layer of moon to 1.

(I think Background Image = ON produce a (small) GGB-Bug: clear the traces if background image is move)

But: When background image is OFF and the layer of moon is 1 the rotated sun (pic1, Layer=0) covert the trace. (for me) this is another, more bad ggb-Bug. But if the simulation were more realistic (the moon does not move through the sun), then the bug would not be disturbing. (Alternative(?): use a sun picture with transparent background)

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FangShin ● 1 month ago

Hi rami, I tried your second method. The sun is rotating again ! Thanks!

Ya I know, the moon and the sun will hit together because the real ratio is too hard to show . I am still trying better option for them.

Really appreciate your help. Big thanks !

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rami ● 1 month ago

a sun with transparent background (tested: it works as alternative to Layer)

also attached a different solution for rotate sun (pic1') (for me: more easy)

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another point:

I think I learned, speed of earth (relative to sun) decreases with increasing distance (and vice versa).

Files: sunT.png sunmoonearth2.g...

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FangShin ● 1 month ago

Hi rami,

You make it sooo perfect ! For me, the code on sunT is so cool!

Learn a lot from you, and good to know that you learn sth here too 😀

Million thanks!

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