Here is the animation:



Not an exciting animation, but interesting for Gimp since it is not a 3D program and making a solid ring that is also animated is quite an involved process. While it appears as one continuous animation, it was made of 60 frames, each with 6 layers. Five of the layers of each frame are animated by multiple applications of Map Object. Additionally, some of the layers switch their positions during the animation to give the appearance of a single continuous animation.

Making something like this with Blender can be done in a matter of minutes. Doing it with Gimp and GAP took hours of planning, setup, and rendering. The challenge is how far one can push Gimp and GAP to make things it wasn't generally designed for.

Background (for the curious):

First, I wondered how I could use Map Object to make a solid ring object. Normally, if you use Map Object to make a Cylinder object and use hollow rings for the top and bottom caps, a cylinder will be created, but it will have no thickness to it's walls. Providing that thickness was the original goal. I did that by making two layers. Once rendered, each of those layers would become the front and back of the cylinder. A third layer was a hollow ring pattern, which I used for the top and bottom caps of the cylinder. I then set up a fourth layer to be rendered as the back inner wall of the cylinder. I rendered that cylinder layer at a smaller width from the first two cylinder layers. The width was not arbitrary in size though. Rather, I calculated what size my top and bottom cap rings had to be and what width factor I would have to use on Map Object to make the smaller "inner wall" of the cylinder match up with the inner portion of those rings.

[Geek alert ]
To make the math specific, I started with a 400x400px image. I made the ring caps outer diameter 400x400. Since the width factor for Map Object for a cylinder object is 0.25, that meant that if I must made a cylinder from a 400x400 filled layer, once it was rotated properly, it would make a cylinder whose outside diameter was 100x100 if the Length factor is set to 0. (400 X 0.25 = 100) The reason the Length factor is set to 0 for the calculations is because this gives us the center cross section of the cylinder. If we have a cylinder whose length factor is 1 for instance, then the diameter of the cap facing closest to us, will appear larger than it actually is, while the diameter of the opposite cap furthest from us will appear smaller. The true size of the cylinder diameter is located at the center slice. This is at Length factor of zero (0). I never set the Length factor to zero (in fact I used a Length of 0.10 for this experiment), I just keep that in mind for the calculations. I set the inner diameter of the ring caps at 320x320. Multiplying 320 by the Map Object width factor of 0.25 equals a value of 80. So 80 would need to be the diameter of the inner wall of the cylinder, to match with the inner diameter of the cylinder caps (at Length factor 0). Since the image was 400x400, getting a value of 80 for a final result required a Map Object width factor of 0.20 (80/400=1/5=0.20) So the inner cylinder wall would be made from a cylinder whose width factor was 0.20. This may be a little confusing, but behind all computer graphics applications is math. The math used for this purpose is simple compared to much of the math applied behind the scenes in Gimp (and GAP).
[/Geek alert]

In order to highlight the 3D effect of the results, I decided to rotate the composite object 45 degrees about the X-axis coordinate, resulting in this:



I then figured out how to rotate it 90 degrees in the opposite direction to get this:



I then started manipulating the rings and applying a few filters coming up with this:



After all of that, I then decided to take the plunge and attempt to animate it. I didn't animate it going a full 360 degree flip, since that would have required more layers and more shuffling of layers during the animation for it to work. Again, the result is rather plain, but doing something like this, really gave me an appreciation for what ultimately goes into a 3D application like Blender, just to make a simple animation. Also, it's a test of just how far Gimp and GAP can be pushed.

Thank you for checking this all out.



P.S.: I have added two XCF files, one an XCF file of a tilted ring, showing the various layers used in making the ring. The other one named used_parts.xcf are the parts used to make the various parts of the animation (with the exception of the background, but that is trivial to add).

WOW ccbarr those are excellent. You sure know your math......

molly,

Thank you.

Very impressive indeed, doing 3D graphics in a 2D program. You sure make GIMP do things the designers probably never imagined it could be used for.
.
Griatch

Griatch,

Thanks for your comment.

It looks perfect to me...congratulations with that. Perhaps the designers may take that on board for future versions of GIMP

akky hi,

Thanks for your comment.

That ring looks like it could be easily made into a roll of duct tape. Your animation is excellent!

Click here

I think you are right "O". How much will you bet that someone will try it? lol

ccbarr that is amazing!

Looks like something done in Xara or another vector graphics program. Nice work with Gimp!!

Extruding a flat 2D object, adding light and texture, then rotating on an arbitrary axis is a non-trivial task using a raster graphics app.

Yeah its phenomenal to say the least.
Is it possible to have a full revolution of the object occur?

I was able to get one step closer to 3-D LOL
I created my own steel bar gradient and applied it to a tall rectangle.Then i rotated it 90% clockwise and ran polar coordinates on it.
The result was a ring with a segment missing so i just copied another part of the ring.Then i merged all the layers into one, and ran GMIC 3-D extrusion and this is what i got.

Good luck Rod!

Didn't work so i deleted the last post about interpolation effects.

That's awesome! The light reflection on the inside and outside of the ring and the shadows are details some might have missed in doing the work just animating it. Well done.

Thanks everyone for your comments. I appreciate it that many understand the notion of how difficult doing something like this would be with Gimp and GAP.



I felt it was possible, and had the idea in mind for quite some time, but it's a matter of having the time and right frame of mind to see it through to completion.

It is true that one can make 3D extruded objects and even animate them using GMIC, however that was not my goal here. It was to use Map Object combined with GAP to simulate a solid ring object, despite the fact that Map Object is not designed to normally accomplish that. However, GAP fills in the "gaps" nicely to allow such an animation to be done.

I like O's idea about the object being used like a roll of tape. Indeed, I could imagine an animation where the roll rolls along on a surface and some tape appears to be placed over the surface as it rolls along. The tape could even tear off with jagged edges like scotch tape has when you tear it off a roll. Would be a bit more complex animation, but certainly doable with Gimp and GAP.

@GnuTux The animation was developed using Map Object mapping various designed layers to various Cylinder objects combined with GAP's Apply Filter on Layer(s) and then doing various compositing actions on the various separate layers to yield the final result.

@Rod, it is quite possible to have a full 360 degree revolution of the ring. The only reason that I didn't do it in this case was time considerations. It would have required a little more complexity, adding at least one more layer to each frame of the animation, and then that layer, like some of the others would have to be rearranged during the animation to make it appear to have a continuous flow.

@Amanda47, thank you for noticing about the lighting and reflections. I must give credit to Map Object for that portion. While it took hours to set this up and render the various layers of each frame, Map Object provided all the lighting effects for this animation.

Thanks again to all who have commented and for recognizing the amount of effort required to do something like this in Gimp (and GAP).

Ccbarr is our official "Lord of The Rings"! Extremely well done!!

I would suggest GAP Master

But LOTR works too

and I agree Extremely well done!