Animated Drawing with Bline on Advanced layer

First of all I am a newbee and maybe a slow one at that! I am trying to achieve the “write-on” effect used by vidoons.com. See example at viewtopic.php?f=6&t=1442 which does not appear to use the same technique. Using the Bline on the advanced layer, (as in the letter U example) when I move the width ducks together at the line start for the first keyframe and have them at the extremities for the next keyframe, I do not consistently get the line to disappear for the first keyframe. Why would the line disappear when the width ducks are superimposed? Do the actual widths of those ducks matter? Do the widths of the two ducks have to be the same when superimposed? If so, how does one change the width ducks width apart from dragging with the mouse which seems very imprecise?

Thanks for any help you can give me.

Hi StanH!

This is because the start or end side type of the widthpoint is set to something else than ‘Flat’. For example, when the widthpoint side type is set to ‘Rounded’ it draws a semi circle at the widthpoint position pointing to the direction of the side. So if you have two widhtpoints overlapped the first with side before rounded and the second side after rounded, you end with a full circle.
If on the other hand each side type is set to ‘Flat’ for each widthpoint that overlaps, it would do just ‘nothing’. Well for each widthpoint it draws a line form the widthpoint position to the widthpoint’s width and then draws back another line to the widthpoint position. The result is to render ‘nothing’.

Yes it matters, but if you use the ‘Flat’ solution it doesn’t matter. You can make the width to be zero exactly at the start frame and non zero at the following one.

No, it is irrelevant. Each widthpoint will render its part, even at the same place.

Any of the widthpoints parameters can be fine edited using the Params panel:

  1. Select the Advanced Outline on the Layers panel or by clicking on the layer at the canvas.
  2. Go to the Params panel. If you don’t find it go to Toolbox->File->Panels->Params and the panel will be visible.
  3. At the Params panel search for Width Point List. Click on the triangle to expand the list.
  4. Click on each widthpoint sub parameter to red highlight it on the canvas. When you find the one you want to modify, expand it with the triangle and modify the width as a normal parameter.

I hope it helped.
-G
Syn.sifz (1.99 KB)
Syn.gif

Thanks-- your guidance, along with your example, did the trick. I see that it is imperative to be able to dig down into the params panel to see the widthpoints sub parameters to see what is going on. A couple of more questions please. Given that the “side type” sub parameter for the width ducks seem to be critical in my situation (i.e. performing the write-on effect), it is not clear what the “tip type” parameter for the layer does. Also the width of the Bline seems to be controlled by the “width” parameter of the width duck so it is not clear what the “brush size” indicator at the bottom of the tool box does.

Finally, in a “write on” effect where you would sketch something with many line segments, it would great if you set a “default” for these pararmeters (e.g. side type, etc.) – I guess that would be too much to hope for.

When the first(last) widthpoint (in terms of its position parameter, not the position on the list) has its before(after) side type set to ‘Interpolate’ the outline continues to the start(end) of the bline. To allow to the user define a type of tip for the bline in those cases, there is defined the start(end) tip type. When a widthpoint is exactly at the start(end) of the bline, its side type before(after) overrides the start(end) tip type.

Yes, final result of the width at an arbitrary position § is: 2*(e+w0.5interpolated_width§)
Where ‘w’ is the layer’s Width parameter, ‘e’ is the layer’s Expand parameter and ‘interpolated_width§’ is the interpolated width based on surrounding widthpoints. Notice that the width parameter of the widthpoint is a real value without units and when it is 1.0 and e=0.0 you exactly have the layer’s Width parameter.
At layer creation, the Toolbox Brush size is used to fill the Layer’s Width parameter.

Yes it might be interesting. Probably the Tool options panel should show dynamically extra parameters based on the type of layers to be created.

-G

Stan (or someone else) - could you write a tutorial on this? I would like to attain this draw-on effect as well, but didn’t even get to the basics on this. The letter U-tutorial seemed to work for single letters, but is too complicated for me if I have to work with the advanced outline for every single stroke.

Cheers
pulmo

Hi pulmo,
the Syn.sif file from one of my previous posts didn’t help? Where exactly do you find complicated to emulate the same thing for other letters?
-G

Pulmo,

I will be glad to write a tutorial on the writeon effect. I am a newbee so I will write it for one who has no experience with synifg. Give me about a day to do it. I have attached an example of outlining North and South America. It consists of 10 Advanced Blines. The ColorSouthcom.png file is the map I traced. The WriteOnNorthSouthsm.gif is the resulting animated gif (cut down in size and to every other frame in order to upload it to this site).

By the way if you are writing letters, I would agree that it would be easier to write in a cursive style. It is easier (i.e. faster) to extend an advanced Bline to cover several letters than to have a new Bline for each stroke.

Thanks,
StanH
WriteOnNorthSouthsm.gif
sfNorthSouthWriteOn.sifz (22.9 KB)

Please see the Write-On tutorial in the wiki section: wiki.synfig.org/wiki/Doc_talk:Write_On

I believed that it was 0.63.01 which has the performance issues. It is exactly the reason to release 0.63.02 just a week after 0.63.01. Setting the Advanced Outline parameter ‘Fast’ to be true fixes it.

Why don’t you use the wiki for this kind of tutorials? Forums is not a good place because it quickly gets lost under the new posts and maybe it is difficult to find for new users.

Thanks anyway!
-G

Genete,

Ok, I will attempt to load under the wiki … you might have to give me some guidance. Maybe you can give me a link showing exactly where I should add it within the wiki.

I confess I haven’t attempted to use 63.02 yet – I was just attempting to show Pulmo the one way I know how.

By the way, you are welcome to delete part one of the tutorial from the forum. I tried and could not.

Thanks,
StanH

There is nothing special. Just login to the wiki, then look to one page of an existing tutorial:
for example: wiki.synfig.org/wiki/Doc:Ball_Bounce
and write the new name at the adress bar:
wiki.synfig.org/wiki/Doc:Write_On
It will complain that the page doesn’t exists. You can edit it and then you have created your first wiki page.
You can try then to look to the internal structure of another wiki page (by editing it or by viewing its source and then you will discover that it has some header structure and some internal markups to create content. Read this will help: wiki.synfig.org/wiki/Help:Editing

Please replace 0.63.00 with 0.63.02 and tell us if you feel some performance problem. Remember to change the ‘Fast’ parameter to be “on” for each advanced outline layer. It is “on” by default. This way you’ll get benefit of the dash option and will avoid the bug of the negative widthpoint positions.

It is ok. Don’t remove it. Just add a link to the wiki’s page once you finish it.
-G

FYI, the tutorial was in the ‘talk’ section by mistake: wiki.synfig.org/wiki/Doc:Write_On and added it to the Tutorials category, so now it is visible from the Tutorials page.