masks are not generated in the same way polygons shapes are. There's a little clever math that will create a vertex mask from a polygon shape but the two paths are completely different. Polygons are created with height, width, radius, and sides numbers. Mask paths are created by defining vectors and paths.
You can't move mask points around numerically because they are vectors not points... Again, completely different methodology in creating the path.
The documentation in the help files is a little sketchy but the tools work just fine when you understand how to use them. Trying to apply polygon shape information to a vector mask is a little like trying to drive a nail with a screwdriver. It's not going to work very well.
But you're missing the point. How would I create a perfectly symmetrical, six sided polygon, dead center in a comp, as a mask, so that I could then edit the positions of the individual vertices over time?
I can make a perfect Hexagon with the path tool. Fine. Great. I can make it dead centre on the comp without a problem. But it's a Shape Path.
Copying and pasting this shape path into a Mask Path apparently should convert it into a Perfectly positioned, perfectly shaped Hexagon Mask that I can then animate the position of the vertices of. But no, this does not work. Despite the documentation above describing doing this very thing.
A work around might be creating a perfect six sided hexagon as a shape path and then converting it to an editable path. But this also seems not possible.
Do you have any ideas how this might be done, or After Effects about being imprecise and just guessing locations and dimensions?
Btw you still don't come close to describing why it's not possible to get at and manipulate the positions of vertices in a mask with exact coordinates. Vectors, by definition, have points which contain position information. For some reason only Adobe knows they've decided to not make this information accessible to the user.
Let's get the terms down accurately. When you're creating a polygon with the shape tools you using the Polystar Path tool to create eithr a Polygon or a Star. This tool sets points, position, rotation, outer radius and outer roundness. If you want a star you also get an option to set an Inner Radius. If you want a perfectly centered hexagon you can draw it manually, change the number of points, radius, or other parameters by the values in the Polystar Path settings in the timeline. You can center it by zeroing out the Polystar Transform position and anchor point. You can also create a centered pentagon by double clicking the tool with no layer selected and then edit the settings in the timeline.
If you want to convert that shape, because it's not a mask path at this point, to a vector mask then you select the Shape Layer and then use the Layer>Auto-Trace tool. To maintain the same number of points that you have in a polygon or a star select the precision to 2 pixels or more.
Now you have a solid centered in your composition with a mask path. You can edit points as you please. If you need to replace that solid with footage you can easily do that by the Shift + Alt/Option + drag method for replacing footage.
The reason you can't select a point on the path and move it by x and y coordinates is that every point in a mask is defined in a single formula instead of every point having their own set of x,y coordinates. Imagine a complex mask path with 1000 vertices. That would give you 1000 stop watches in the time line, one for each vector. It's not practical.
If you want to select a single vertex and move that vertex to a specific position you can either use the arrow keys for a pixel at a time or shift + arrow key for 10 pixels at a time, or set a guide and let the vertex snap to it. AE does not posses the same transform controls you get in Illustrator because, if you need to animate those points, they all need a timeline. As I explained above, given the current UI, this is not practical in AE.
I use both AE and AI almost every day. I've never found it necessary to move a vertex in either program by entering position values directly. I don't have the time to do so. Snaps have always done it for me.
I hope I've solved your problem of creating a Mask Path from a Shape...
Here's a situation where you might need what I'm asking for... vertex specific editing.
Move two vertex on top of two others. Move forward in time. Pick the vertex you want (magically) and move it. If you've picked up the wrong one (because After Effects doesn't let you know which one you've picked up or allow you to choose which of the two overlapping vertices you're picking up) then you're forced to move it and then pick up the other, move that where you want it to go, and then somehow magically get the other one back to the exact same location it was previously in. Which can't really be done because you can't snap guides to vertices. Not being able to snap guides to things on the screen is one of the single most annoying absent features in After Effects. It makes guides almost useless as you'll always have to first find where the point is, then manually place a guide close to that position, then zoom in and jiggle around until you get it at exactly that point - because like vertices there doesn't seem to be text entry for guides.
Who does userability testing for After Effects? Have they never used a 3D program, a real one?
As to not being able to edit vertices in the timeline being an issue due to how it might clug up the timeline... consider this, for primitives and paths with less than (user arbitrary number) it might be the best thing they could expose to their users for shape and polygon editing. It's clearly already there - see the info panel when you pick up a vertex, it has the exact location of that of it, and you can move it with an arrow key. - BUT -- Why do I have to actually pick up and be dragging a vertex before I can see its position? This is inherently inaccurate using a mouse, trackpad or pan, as their's movement resulting from the click required to pick up the vertex to see its positon information in the info panel. Surely a single tap-select should reveal that position information if only one vertex is selected. But no. That would be too useful for the consumers wanting to put a guide on exactly that spot so they could possibly return a vertex to that position at a later time.
Again, none of this would be a problem if there was vertex position information accessible to the user. Like every other REAL 3D program.
The odd thing about all that I'm asking is this... I need to use a mask to do the animation I want simply because there's no vertex timeline editing of shapes. Forget about masks with their possibility of thousands of vertices... my main concern is getting a rather nifty little (ACCURATE) animation with a shape. But it's not possible because of the nature of the vertices in AE without using a couple of masks to fudge around inaccurately, slowly, and clunkily.
This whole experience much reminds me of when I first tried Illustrator, which might still be one of the most clunky creative programs. Certainly the worst of the vector editing programs.
GIven that After Effects is now 3D (sort of) I'd highly suggest anyone looking to do anything in terms of drawing have a look at the spline tools in any of the real 3D programs. (3ds max, Maya, Cinema4D etc) - You'll find the level of flexibility and editability of splines to be truly extraordinary after a life in Illustrator and After Effects - just as coming the other way is incredibly non-intuitive, painful and indicative of just how dated the paradigms, conventions and contrivances of After Effects and Illustrator are.
Adobe could go a long way to solving this problem for those crossing over if they took the time to explain their paradigms and conventions in a couple of paragraphs, and perhaps fessed up a little about the possible nuances and limitations inherent to their approach. This would save everyone a lot of time.
And it surely wouldn't hurt them to actually write something a bit more accurate in terms of documntation. That I can find something so flawed as this line, and that Rick has to resort to "Auto-Trace" (with all its dubious accuracy) to turn a shape into a path for a mask is really rather anti-quated.
Rick, if you've still got patience, why, when I follow your steps exactly, does the info panel tell me I've picked up a vertex from a Mask with 8 vertices? Even if the first and last vertices (wherever it arbitrarily decided to close the mask) were two overlapping vertices, that's only 7.
Next question... how do you "Select" a vertex with a trackpad without picking it up?
Here's another interesting "feature". The vertices exist in a numerical space twice that of the composition they're in.
So an [x,y] of [110,30] for a vertex as shown in the info panel is actually [55,15] for a guide. Nicely intuitive. I'm sure there's some very logical reason for this. I'm keen to hear it.
If you want to select only a single mask to edit then just lock the mask in the timeline. If you have no mask selected the top mask will be picked. If you want to select one of the lower masks just select any path between vertices on that mask with the direct selection tool and then select the overlapping point. The proper vertex will always then be selected and you can verify that by checking the timeline. BTW, I cycle my mask colors so they are easier to work with.
You can also easily lock masks in the TLW:
I'm not following your info panel question. If you have 8 vertices you have 8, not 7. The count does not start at 0. You can select and set the first vertex. The info panel accurately shows the position of a vertex in composition space NOT layer space. Even without guides you can quickly place a vertex any where in the comp window you want by looking at the info palette.
As far as saving time, I work accurately with Illustrator and AE as fast as I can click and drag. I have for years. While there may be other ways of working, most users find masking easy and straight forward. I personally prefer clicking and dragging by eye to typing in numbers.
You've missed the point.
The overlapping vertices are on the SAME mask. Meaning sometimes I want them overlapping, and sometimes I don't. How to "un-overlap" them accurately?
As to the point about 8 vertices... it's a hexagon, I converted it (via the rather dubious "auto-trace" as you suggested, and got 8 vertices, not 6 (what one might expect) and not 7 (what one might expect if the start and end vertices were two overlapping "welded" vertices)
I see what you're getting at about mvoing things with mouse and checking things with your eye... I'm after more precisiont than that, am making pixel art for games.
bttw this is the second time you've referenced how wonderful you find the software for the way you work. Great. FOR YOU!
I can assure you I've not considered much in the way of doing things in AE, having come from 3D... and yet in my first couple of trials with the software I'm already finding rather odd limitatations that one might expect Adobe to have overcome with its flagship product given the prevalence of rather exacting vertex editing in just about every other animation software in the world.
So while you may well be accustomed to working within Adobe's limitations, and feel great about it, that helps me nought unless you can try to see things from the perspective I've layed out - that I'm looking for PRECISION and REPEATABILITY with EASE.
I realise it's possible to drop guides by looking at the info panel.
Draw a Hexagon and try to set a cross up guide to each of the six corners so that you can find those positions later with vertices you move around for the sake of geometric animations. You'll find it's a rather long and tedious process (needlessly) becasue there's not snapping of the guides to the vertices in either a mask or a shape created with the polygon tool.
The only thing required to rapidly speed up this process is snapping to vertices... then, ironically, there'd be no need for the guides, as one could drag and drop vertices ontop of vertices with accuracy, like ANY other vector program in the world.
This thread has been branched into two pieces.
For an explanation of how to copy and paste from shapes to masks, see this thread:
Let's continue the conversation about per-vertex manipulations on this thread.
First, note that this is listed as one of our top feature requests here:
If you agree (which you seem to), then please submit a feature request to add your vote.
Note that we do provide scripting access to individual vertices, as demonstrated here:
Many folks use this to create utility scripts.
Added a feature request "vote(?)"
And for vertex snapping.