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interpolated vertices/anchorpoints of shape path

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Alfred Steinerinterpolated vertices/anchorpoints of shape path
by on Jul 19, 2015 at 7:02:35 pm
Last Edited By Alfred Steiner on Jul 19, 2015 at 8:52:41 pm

Hello,
Does anyone know where this vertex/anchor point of my animated shape path is coming ?
i think it has to do with some keyframe interpolation, anyways is there a way to disable it?



i just found out that the number of these vertices (which are only visible if the cursor is between the keyframe) equals the number of vertices which are added in the next keyframe... but I still dont know avoid them.

I made a script to manage it somehow but thats not the best solution. Id prefer a non script option.
// G L O B A L S
var theComp = app.project.activeItem;
var theLayer = theComp.layer(1);
var thePath = theLayer.property("ADBE Root Vectors Group").property("ADBE Vector Group").property("ADBE Vectors Group").property("ADBE Vector Shape - Group").property("ADBE Vector Shape");

for (var i = 1; i <= thePath.numKeys; i++) {
var getVerts =thePath.keyValue(i).vertices;
if (getVerts.length > 2) {
for (var n = 0; n < (getVerts.length-2); n++) {
// Mittelpunkt zwscihen Vertex n und n +2 berechnen
var middle_x = getVerts[n][0]-((getVerts[n][0]-getVerts[n+2][0])/2); // absolute differenz between x = coordinated
var middle_y = getVerts[n][1]-((getVerts[n][1]-getVerts[n+2][1])/2);
// ├╝berpr├╝fen ob der dazwischenliegende Punkt dem errechneten Mittelpunkt entspricht
var test_x = Math.round(getVerts[n+1][0]);
var test_y = Math.round(getVerts[n+1][1]);
if (Math.round(middle_x) == test_x && Math.round(middle_y) == test_y) {
//alert("found");
getVerts.splice((n+1),1);
n--;
}
}
}
var myShape = new Shape();
myShape.closed = false;
myShape.vertices = getVerts;
thePath.setValueAtKey(i,myShape);
}


have a nice day,
Alf


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Dave LaRondeRe: interpolated vertices/anchorpoints of shape path
by on Jul 20, 2015 at 5:46:39 pm

I hope you realize that you're using Hold keyframes. Once AE encounters the next Hold keyframe for the Pfad property, the change is instantaneous.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


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Alfred SteinerRe: interpolated vertices/anchorpoints of shape path
by on Jul 21, 2015 at 10:36:09 am

Ah okay i didnt know this. Is there another possibility than using Hold Keyframes if i want to avoid any interpolation?


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Dave LaRondeRe: interpolated vertices/anchorpoints of shape path
by on Jul 21, 2015 at 4:06:16 pm

If we knew what you were trying to accomplish with a keyframed expression, we might be able to give you better help.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


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Alfred SteinerRe: interpolated vertices/anchorpoints of shape path
by on Jul 22, 2015 at 9:23:28 am

Hi okay then I will describe it.

i have a 30 fps Video of rain drops falling into a puddle. now I begin in the first Frame and look where the first rain drop hits the ground. From this point i want a line to be drawn to the second drop which hits the ground and from this one to the third and so on.
so over the frames the lines evolve to a graphic.

i hope one can understand this.

regards,
Alf


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Dave LaRondeRe: interpolated vertices/anchorpoints of shape path
by on Jul 22, 2015 at 4:31:01 pm
Last Edited By Dave LaRonde on Jul 22, 2015 at 4:33:28 pm

I hope it's a locked down shot! If it is not, re-shoot!

There is ABSOLUTELY NO NEED TO USE EXPRESSIONS to do this. In fact, you are simply over-complicating matters by attempting to use expressions.

So why don't you use After Effects the way it was intended to be used? Here's the drill:

Select the pen tool and highlight the clip. Find the first raindrop's point of impact and click on it. You've made the first vertex of what will become an open mask path. Now find the second point of impact and click. Repeat this procedure until done.

De-select the pen tool when done. You now have an open mask path, which you can now copy and paste into the Brush Position property of the Write-On effect, which you will apply to the video layer. Now you can move the property's keframes around to get your timing right, add keyframes to pause the drawing of the line, and modify keyframes and Bezier paths if you wish to make the lines straight or curved.

Your reliance on using expressions to do things they were not intended to do reveals something important -- you're trying to use After Effects on your own because you think you know everything already. You are using AE without learning the basic assumptions and procedures of this application, and you have become hopelessly lost. You are trying to solve everything with code, and code does NOT solve everything.

If you want to have ANY kind of success in AE, it is ABSOLUTELY ESSENTIAL to have a thorough grounding in the basics.

I STRONGLY recommend that you spend a lot of quality time investigating the training links you will find here:

http://blogs.adobe.com/aftereffects/2010/01/getting-started-with-after-eff....

One of those links will lead you to the very fine set of tutorials on the COW done by Andrew Devis on AE Basics.

Be warned -- you ignore Basic Training in After Effects at your own peril.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


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