twister effect

[h0ffman]

Originally Posted by Coagulus

loving this thread. It's probably one of the best resources on the net about it now. Now how about all the other effects....

I couldn't agree more Coagulus, been a real eye opener for me. We need more like this really.

Was thinking it might be worth having a "Classic Demo Effects Explained / Tutorial" sticky thread with links to each of the threads which explain it.

I know there is a Chessboard thread on here somewhere....

[Dunny]

Originally Posted by h0ffman

I couldn't agree more Coagulus, been a real eye opener for me. We need more like this really.

Was thinking it might be worth having a "Classic Demo Effects Explained / Tutorial" sticky thread with links to each of the threads which explain it.

I know there is a Chessboard thread on here somewhere....

+1. I've been loving this thread as a way to get ideas of what to try next in SpecBAS and so far been having a blast! It would be *ace* to learn how all the tricks in the old demos were done (and some of the 40k's explained would be neat too)...

Tunnels and textured cubes, dot-balls and swirly rotatey things and all sorts!

D.

[deicidal]

Yep, I also agree to a Classic Demo Effects Explained / Tutorial". This has been a fascinating read.

[AlfaRomeo]

Originally Posted by Dunny

It would be *ace* to learn how all the tricks in the old demos were done (and some of the 40k's explained would be neat too)...

yeah!! I second that too

[Lonewolf10]

I already know the theory behind how alot of the effects were done, but I have enjoyed reading this thread too


Regards,
Lonewolf10

[h0ffman]

Can we get a mod onto this?

[Codetapper]

A separate website with a page for each effect would be the ideal solution imho! Someone would need to compile a list of effects needed and the experts here that know efficient ways to do them would have to write up some docs. Off the top of my head:

Full screen zoomer
Blitter tornado
Maybe some basic cube rotation
Sinus scroller
Jelly
Plasma
...

[korruptor]

Most of them have already been discussed on here and ADA

[Lonewolf10]

Originally Posted by korruptor

Most of them have already been discussed on here and ADA

I agree. I already have some sinus scroller code which shows how easy it actually is

I would love to know how to merge one screen into another (not wiping). I was playing around with Vmorph earlier and although it's made in AMOS it does a fairly good job of morphing one image into another - however it's not true morphing (it basically fades out one image, and fades in the new one over the top). A very simple example of what I am on about would be if you morph a circle/ball into a square. Morphing full images would be complicated, right?


Regards,
Lonewolf10

[gibs]

Very interesting stuff !

[pmc]

Originally Posted by Lonewolf10

I already have some sinus scroller code which shows how easy it actually is

True, but this illustrates a fundamental law of the universe: everything is easy - when you know how.

The coders of today are just standing on the shoulders of the giants that were the pioneering coders of the past.

Personally I'd rather not have a discussion of how to do all the effects that have ever been done - if you know it all the fun is gone from the discovery. Although that's just my opinion of course.

[StingRay]

Originally Posted by h0ffman

Ez Stinger

But, the logo would be different on each line, thus multiplying the twister by the number of lines of the logo surely??

If you want to have a logo it'll be a bit tricky but if you use a texture that is symmetrical, drawing the textured twister is done exactly how I said. Instead of using bitplane pointers for each line you can also set the modulos for every line which saves a few cycles and needs even less memory (less data to write).

Originally Posted by pmc

True, but this illustrates a fundamental law of the universe: everything is easy - when you know how.

Exactly! Everything is easy once you know how to do it. The fun is to figure out how to do something.

Originally Posted by pmc

Personally I'd rather not have a discussion of how to do all the effects that have ever been done - if you know it all the fun is gone from the discovery. Although that's just my opinion of course.

I agree.

Originally Posted by Lonewolf10

I would love to know how to merge one screen into another (not wiping). I was playing around with Vmorph earlier and although it's made in AMOS it does a fairly good job of morphing one image into another - however it's not true morphing (it basically fades out one image, and fades in the new one over the top). A very simple example of what I am on about would be if you morph a circle/ball into a square. Morphing full images would be complicated, right?

Morphing full images can be done but it's not that easy. "Simple" morphing is easy. What kind of morphing are you looking for? Something like I did in this demo: [ Show youtube player ] ? (3:38, Desert Dream part) Or something different?

[Lonewolf10]

Originally Posted by StingRay

Morphing full images can be done but it's not that easy. "Simple" morphing is easy. What kind of morphing are you looking for? Something like I did in this demo: [ Show youtube player ] ? (3:38, Desert Dream part) Or something different?

I didn't watch the whole demo, but I bookmarked it to watch tomorrow
I laughed at the beginning (western) because I watched a western double-bill at the weekend - Shootout at Medicine Bend (James Garner) and El Dorado (John Wayne).
I loved the whole flicking through TV channels idea

Anyway, yes the bit just after 3:38 (circle morphs so it has teeth) is the sort of thing I was after (I don't expect to be able to morph someones face into a cat's head just yet!).
I would like to know how to morph a filled circle into a square. Could you point me in the right direction, please?


Regards,
Lonewolf10

[pmc]

Back onto twister related stuff...

I've been playing with generating pre-calced twister bitmaps. What this is giving me is a twister that kind of looks like a twisted ribbon. See the picture attached.

Is this normal? Did I fuck something up or, with a bit of extra code to stretch and relax the ribbon, have I just invented a new effect?

EDIT: Actually carried on messing with this and with a slight tweak I got my precalc bitmap to look like one continuous strip of twister instead (see new pic) - I suppose that's more how it's supposed to look?

Regardless - I'll add some giant copper list code as per the previous discussion and play with the different pre-calc bitmaps. Maybe I'll get some interesting effects

[Lonewolf10]

Originally Posted by pmc

Back onto twister related stuff...

I've been playing with generating pre-calced twister bitmaps. What this is giving me is a twister that kind of looks like a twisted ribbon. See the picture attached.

*snip*

EDIT: Actually carried on messing with this and with a slight tweak I got my precalc bitmap to look like one continuous strip of twister instead (see new pic) - I suppose that's more how it's supposed to look?

Personally, I think the "twisted ribbon" effect looks cooler, and would look even better moving


Regards,
Lonewolf10

[pmc]

Yeah, I quite like it too.

A static image is one thing, now I just need to get it moving nicely.

If I generate anything worthwhile it'll probably find its way into something I'm working on now...

[Coagulus]

Originally Posted by pmc

Personally I'd rather not have a discussion of how to do all the effects that have ever been done - if you know it all the fun is gone from the discovery. Although that's just my opinion of course.

I agree but some of the classic and probably well know to most demo-coder effects like the twister and the one in your avatar would be good! Demo coders are like magicians and have to have some tricks secret.

ps, loving your ribbon but keep picturing a scrolltext wrapped round it too!

[WayneK]

That was actually one of the first times I saw a 'ribbon' effect, was a vertical scroller 'around' a ribbon. Done by setting 8 new cols every line (with the copper, although this was actually on the Atari ST so I guess Timer B!) to makeup the 'pixels' of the chars required... you can of course precalc a ribbon to twist around itself, so have 2 scrollers twisting around each other, or a darker/shaded version of the scroller on the pixels which are behind the ribbon for added '3d' illusion trickery!
Quite a nice looking effect if done well, and importantly (as with all things I like to code) amazingly easy to do

[Lonewolf10]

Originally Posted by Lonewolf10

I would like to know how to morph a filled circle into a square. Could you point me in the right direction, please?

It's ok, I managed to work out how to do it myself. Using cartesian coordinates to work out the coords of the circumference of the circle, I can then work out intermediate frames as I know the final coordinates. All coordinates will be joined together by a line.

If that doesn't quite make sense, I have included a simple example with 1 intermediate frame. In my finished morphing routine I will use more than 1 intermediate frame


Regards,
Lonewolf10

[pmc]

I now have my own twister twisting away nicely and running just fine on 68000.

Gonna include it in the current project I'm working on.

EDIT: Just measured and it takes only 33 raster lines to do the twisting. I did all the coding in my version myself without referring to any of StingRay's example code but would I have got there without Stinger's expert advice and guidance in this thread...? Another proof that it really is easy when you know how.