I'm almost out of time and bartovan suggested there might be enough people interested here so that I make a thread. So I'd better post this now before I disappear into the void and in case someone else on the net comes looking for the same thing I was a few years ago.

Yet Another Interpolator

This will let you make very simple animation in Inkscape. Usually this means just paths and filled paths (no gradient, masking, etc yet).

This was mainly made for my own use which would explain some of the clunkiness.

Here are two usage examples

• http://gfycat.com/WillingWiltedFrog
• http://gfycat.com/CarefulImpishDuck

All links

• https://code.launchpad.net/~yai-alpha/inkscape/yai-alpha
• https://github.com/yaii/pyink-lite
• https://github.com/yaii/ipyconsole
• https://github.com/yaii/yai/blob/alpha/README.md

See "What this actually is" below for a description of what they are.

Getting started
Running

Since it is experimental, it has to be built first. It isn't just some file that can be downloaded and run (yet).

I will edit this part and add links here if people build binaries for particular systems and host them. If there is enough requests, I could also try to make builds (mostly only Linux though).

Building

All the dependencies for compiling (regular) Inkscape are needed plus

• Python 2.x (including header files) Versions 2.5 to 2.7 work, I haven't tried others.
• PyGTK (pretty huge, may eventually not be needed)
• Cython (to build and may not be needed even for that if a pre-compiled .cpp file is distributed) Version at least 0.17 I think but I've been using 0.22 lately

Get the branch here


Then either follow the instruction for compiling Inkscape with an extra autogen at the start

or use cmake.

Then drop these files somewhere pyink-lite

Read the usage example from the pyink-lite github page.

When the (modified) Inkscape starts, in preferences change paths to use absolute and repeated coordinates!

Not all functions are exposed as UI or menu items (in fact, there are no new menu items)! See "Missing user interface" below.

What this actually is

Some Inkscape Python binding (in Cython), a GTK IPython console and a sample UI for making animation.

The Python bindings can be thought of as a more permissive extensions system (Inkscape already allows Python extensions of some sort). Then the animation interface is an example of Python binding extension.

Here's some credits and some more technical rambling. Note this github version is a bit dated (it was based on the stable version of Inkscape 0.91 and doesn't work with cmake).

Missing user interface

There are buttons missing so its not possible to just open it up click around and see immediate effects. But they can be added, even on the fly as Inkscape still runs (hopefully this can be done faster later on). This is done using either the python (the long empty text box above the slider) or ipython console (the large box at the top with "In [1]:"). Some user interface is nonetheless still missing.

Example for adding a button to select all things filled red.

Why is this?

In other programs, you usually have to "learn to use" the program before starting. Figure out all the menus and buttons it has. And that's all fine if you plan on using the same program for a long time (but then the UI changes when version changes...). But sometimes you already know what you want to do and what the program should do.

Here (ideally) you would instead read what the program is capable of and then make up the interface as you go. The intention is to instead (eventually) make it so that an interface can be created quickly so you can make the interface you want for how you want to use the program.

Taken further, you could even make one interface per file or project (or just slight modification of an existing interface). There's even a Reload code button (which uses xreload.py which is known not to work 100% of the time but when it does work it saves a lot of time and in the worst case you can just restart Inkscape).

It will of course be possible to always stick to the same interface and forget all this.

Known issues

Crashing on some undo
Because the UI and drawing are both on the canvas in the same file, undoing something that changed the UI (above the document area) will usually result in a crash.

Questions and answers

Q: How do I export my animation to a video, .gif or other?

A: There used to be an export option (which just called the command line version of Inkscape many times) but I ended up regularly using a desktop recorder so right now this is the suggested way to go.

Q: How does this relate to SMIL and other animation standards?

A: It ignores them but the description is hopefully simple enough that it is (will be) easy to export to other formats.

Stuff I could do

Depending on demand.

• Answer questions on how to do this. There is probably a lot I've missed here.
• Write more, especially on not well exposed features.
• Clean up the frame table sample UI and make it available.
• Put an actual license on the extension. It will be open source, just have to pick one.
• Show more samples.
• Finish this list.

Realistically probably won't do all of them soon though.

How to help move this forward

Not entirely what's more important (well, I know the answer for my own use but not others).

• Write tutorials, fill in documentation.
• Design some good default user interface.
• Figure out how to use Inkscape's selection (and maybe other tools) as user interface elements, in a way that makes sense and doesn't crash things.
• Read the code and try to organize and simplify it.
• Wrap more of the C++ code to make it available to Python.

Conclusion

So in conclusion, batman. http://gfycat.com/EverlastingFearlessCony (Paths stolen from here.)

Waw

It looks really interesting to me (that's why I suggested you to talk about it here), but I have one big problem (which maybe other Inkscapers will have also?): the installing and getting it work part seems a bit over my head...
You did a great job explaining how to do it, and I would probably be able to reproduce it all and get it working, but I have no idea what it actually does and I'm afraid I'll end up with a load of stuff of which I don't know how it works, and after updates get it all messed up etc...

I'm not a programmer, and probably most users aren't... Would there be a way to make it a bit more "package" like in some way? Maybe even Inkscape and your animation code integrated into one "thing" (an Inkscape version) that could be installed by compiling (or even package management, although that's maybe too complicated)?

As I see it (speaking for me personally then), this might be the first priority, to make it easier for plain users to get into this boat?
That, and, as you mention, a default working interface (nothing fancy, just something that works)...

And one other question, what's the concept behind your animator? You seem to use layers? Or how does it work basically?

Hi bartovan,

Those are two good points.

bartovan wrote:Waw

It looks really interesting to me (that's why I suggested you to talk about it here), but I have one big problem (which maybe other Inkscapers will have also?): the installing and getting it work part seems a bit over my head...
You did a great job explaining how to do it, and I would probably be able to reproduce it all and get it working, but I have no idea what it actually does and I'm afraid I'll end up with a load of stuff of which I don't know how it works, and after updates get it all messed up etc...

I'm not a programmer, and probably most users aren't... Would there be a way to make it a bit more "package" like in some way? Maybe even Inkscape and your animation code integrated into one "thing" (an Inkscape version) that could be installed by compiling (or even package management, although that's maybe too complicated)?

As I see it (speaking for me personally then), this might be the first priority, to make it easier for plain users to get into this boat?
That, and, as you mention, a default working interface (nothing fancy, just something that works)...

There are two possible answers to this one. As you suggested, if the changes needed to allow this kind of extension is included in Inkscape than a future version of Inkscape will have all packaging distribution issues more or less solved. I would only have to provide the extension part for you to load up (instead of having a custom compiled Inkscape).

Otherwise, we'd still need at least one person per system to make it available and compile it (and host it or I can put it up somewhere). I don't know if its a good idea to have it as a package yet. I think for the moment, its better to keep the one file as a binary. I could make a .zip of everything though.

Now, you said you use Ubuntu 15.04. Can you tell me which version (32 bit or 64 bit? Run uname -a and look for i686 or x86_64).

bartovan wrote:And one other question, what's the concept behind your animator? You seem to use layers? Or how does it work basically?

This is one of the things I wanted to write more about at some points. Here's the brief version.

There are two parts, but only one is avaiable now.

animtree is used to help arrange many animations. Its just get the right delays if you have lots of things that are supposed to happen one after the other. It only lets you say "this animation should start as soon as that one ends".

You could instead figure out the number of seconds of delay from the start for each animation and ignore this part.

frametable is for making a single animation. Draw different versions of the same paths (with the same of points) that represent it at different times. The paths just need to be given ids that looks like path2966-0, path2966-1, path2966-2, ... They don't need to be placed in any layer in particular.

After that, decide on how the path should look between those times. In other words, interpolate. Here you can pick any function as an interpolator you want here. The default interpolator is the cubic function.

The basic version interpolates each coordinate of each point on the path separately. The interpolator only provides the speed at which coordinate changes. All points are still going to move in a straight line from one point to the next.


The point in this picture would follow the red line.

It's instead possible to move both x and y coordinates together.


The point will follow that path you'd get if you put a smooth point at every midpoint (a Catmull-Rom spline). This part is not very customizable.

You could easily make the paths and set their ids to path2966-0, path2966-1, path2966-2 easily using just regular Inkscape. And then use some extension to generate the animation. But then you couldn't visualize the results as you edit (I found no way to export quickly). The frame table is basically just there to help with drawing these paths. Easier copying pasting, changing time point and setting opacity for nearby time points ("onion skinning").



Both interfaces lets you visualize the image at an intermediate point by dragging a slider.

yaii wrote:if the changes needed to allow this kind of extension is included in Inkscape than a future version of Inkscape will have all packaging distribution issues more or less solved. I would only have to provide the extension part for you to load up (instead of having a custom compiled Inkscape).

That would be great.

yaii wrote:Now, you said you use Ubuntu 15.04. Can you tell me which version (32 bit or 64 bit)?

64 bit.

Personally what interests me most is frametable, seems promising to me. But I'm afraid that until the testing procedure would become somewhat easier (just loading up the extension), it will be a bit too much for me to get into trying it out... Don't want to spoil the party, but I'm just a simple user after all, and I actually hate passing time trying to fix my system (I've borked it soooo many times experimenting, each time thinking "oh it's just something simple, I'll manage", now I just want to use it and keep it usable). Like I need to keep in control somehow. Loading up an extension is no problem, but the different Inkscape versions path is a bit too much I think... Maybe in a virtual machine though, that could work...

Can you interpolate also other attributes, like colors for instance?

bartovan wrote:

yaii wrote:Now, you said you use Ubuntu 15.04. Can you tell me which version (32 bit or 64 bit)?

64 bit.

Here is a binairy for Ubuntu 15.04 x86_64. I don't use it so it is not at all well tested.

https://github.com/yaii/inkscape-binaries/raw/master/inkscape-ubuntu-vivid-x86_64

You still need to download the other zips mind you pyink-lite and ipyconsole

bartovan wrote:Personally what interests me most is frametable, seems promising to me. But I'm afraid that until the testing procedure would become somewhat easier (just loading up the extension), it will be a bit too much for me to get into trying it out... Don't want to spoil the party, but I'm just a simple user after all, and I actually hate passing time trying to fix my system (I've borked it soooo many times experimenting, each time thinking "oh it's just something simple, I'll manage", now I just want to use it and keep it usable). Like I need to keep in control somehow. Loading up an extension is no problem, but the different Inkscape versions path is a bit too much I think... Maybe in a virtual machine though, that could work...

I'm not sure which part you are most afraid of but I'm guessing you've followed instructions that messed with some systems files before. This doesn't do that. In fact, that's why I'm a bit recluctant to make any package (like a .deb) available. This is the surest way I know

Normally (regardless of what we are talking about here), you could also use a chroot as a lighter version of a virtual machine (or schroot if you want things more automated).

Here's how I built this binary from another Debian based system. The first steps incidentally creates a chroot.



I have not looked into the poppler include or inttypes.h errors here. These are just quick fixes.

After this step, I could checkinstall but decide to just copy the binary bin/inkscape.

bartovan wrote:Can you interpolate also other attributes, like colors for instance?

Yes! But right now fills are in the wrong place (in the animtree's UI). There's fill-opacity, stroke-opacity, opacity for the moment because that's what I needed. But others should be easy to add.

However, its interesting that you pick colors. Because they look a bit odd if you interpolate red, blue, green values separately (that's the easiest to do because that's how they are usually represented). So there's also interpolation in terms of hue, saturation, lightness.



There's also interpolation by transform (instead of points) set up somehwere. But because multiple transforms are usually all combined into one and can't always be separated (there's more than one way to get that matrix), it it quite limited.

You said else where that

bartovan wrote: I'm waiting for the perfect interface

but instead of waiting, this is your chance to try and describe the interface you are thinking of. No need to wait for a showcase of programs to pick one!

OK. Actually, I'll go for a virtual machine and follow the instructions you posted in the beginning, seems the most transparent to me and at least I'll know what I'm doing. It may take some time before I can install it, I'll be going on holidays soon etc. So if I don't react promptly, it's not because of a lack of interest

YAI you really shared a good guide and here i came looking for the same thing you was a few years ago.....this will really let me make very simple animation in Inkscape. Thumbs up!