Feedback Splines Feedback

This a thread about the experimental package of the Splines, ie an older version. A much better newer preview version will be released soon.

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First time user and early feedback is important, so I thought I'd share my experience on the experimental package.

Adding a spline was easy, modifying it wasn't. I had to figure out that there's a small dropdown here that you have to change:



I somehow can follow why this is there, but when I click on a spline gameobject, i'd like to be in its edit mode. However, if that separation is necessary, then there should be a keyboard shortcut.

In order to edit a knot (why is it called knot, isn't that an anchor?), you have to first click on each and every single one of them. That's too many clicks:


The handles should all be visible and instantly modifiable.

Inserting a new knot is circumstantial. You can only insert new ones along the spline, but not outside.



So you have to click the insert tool first, then insert the knot along the spline, then move it outside. No idea yet how to snap that point when you move it.

Moving the start point is an arrow down. That's confusing. It should be an arrow along the spline since all you can do with it is move the knot along the spline:

 

The rotation arrow is nice, but this should be a delta. Or in addition to the arrow it should show the delta from the up direction:



Could be visualized differently, eg as cake shape with transparent fill.

 

It is visible if you select the Bezier mode instead of Catmull mode (which should also show the tangent direction by default though)

 

Not for me:



I can only move 1 knot here. In order to move another I first have to click on it.

 

I moved the spline. It's nice that all knots move with it, but the next question arises instantly: How do I snap them all to the terrain?

 

I wanted to write my own spline editor, but there doesn't seem to be an api which allows to delete a knot:

 

There's the AddPointToEnd method. But for the user it's irrelevant where the spline starts or where it ends. There should also be an AddPointToStart method. This also reflects in the UI:



I can only add a point at the end, not at the start.

 

Here's an example about how I did the editing with YAPP:

It would be really nice if we could get something like that from Unity.

Or at least if we could write our own editor.

 

Deleting should delete the closest knot at the press of a hotkey and mouse click. Not click, then hit the delete key and that over and over. That's tedious, especially for longer splines.

Here's an example, starts at 01:19:

 

Btw regarding the above mentioned adding: The adding of a knot is nice this way:



But this kind of adding is snapping. That should happen only using a snap hotkey.

 

Some of my knots are in the air, no idea why. I thought they should snap to the terrain.

Also, I added 33 knots. How do I restart? There doesn't seem to be a clear or reset button:

 

Why are the knots using float3 instead of Vector3?

 

I guess to make them compatible with burst or integrate them with DOTS in the future

 

Ah, that makes sense then.

 

Please add a triangulator utility class, e. g. used for the closed spline. Should consider the resolution of the curve. I tried with the Spline Square preset and a quick triangulator I took from the web:



It can come in very handy, e. g. using terrain projection:

https://forum.unity.com/threads/wow-terrain-projection-is-super-fast.1005583/

Basically one could select multiple houses as settlement, align their height, create a closed spline around their bounds with height of their lowest vertices, create a triangulated mesh (invisible, on a dedicated layer) as the "floor" and drag that settlement around while the terrain aligns properly to the mesh. Not just the houses, but the spline area around them. It's a special use case, but a valid one nonetheless. But it starts with the triangulation.

 

That could also be cool for intersections. IIRC they want to focus on a good editor UX though so that the core functionality (creating splines) is really solid before adding more utilities though, which IMO seems like a good way to go. Otherwise I agree with all your suggestions, except that those might be a good fit for a community/open-source spline tool based on Unity's splines

 

It would be nice to have a simpler default constructor additionally:

 

An official, standalone and lightweight topology package would be ideal (for common needs like triangulation, edge loop fills, welding, simplifying, etc.), so for example if we're creating a game or asset that requires splines and triangulation, we wouldn't need to include or require people to install ProBuilder.

Generally speaking, I think ProBuilder is being used as an editor-only tool - I don't personally include it in builds, but can toggle use with a scripting define symbol for parts of my toolset that make use of it. When some of us are putting effort into stripping every possible library from a project, needing to include ProBuilder just for access to triangulation might feel ..excessive? In other words, while a supported solution is desirable, there's less incentive for people to use it - for runtime purposes in particular - if it's only available as a part of ProBuilder. I would personally prefer to see an official and lightweight Unity package dedicated to topology (or at least triangulation).

Maybe as a stepping stone, triangulation could be extracted from that to an early/experimental package and then ProBuilder [and whatever else] could use that? If you might now be looking at exposing it for more general purpose use anyway and will be digging around in related code.. please consider it.

 

There should also be an "always snap to y-axis-raycast" option. And a button to snap all points of the spline, so that one doesn't have to click each and every single one of them for adjustment. See video below.

A better choice is to use the mouse and a hotkey. See video below.

No, no point at all. It should be my choice to select a start point and the next point. If there's none or a single point, then of course then there's no spline functionality invoked.

You can try yourself, it's free, but here's the video:

• 00:00 always snap and add control points at the beginning or end
• 00:12 add control points between spline points. you covered that, but what I show is the indicator and that add and remove are actually the same, but with different keyboard key pressed
• 00:19 delete control points shows an indicator of a red line. you don't even have to hover over the control point, it just targets the closest one
• 00:22 delete control points. you see, i don't even have to be close. i hit ctrl+shift, then i'm in delete mode and i just delete via mouse click
• 00:36 clear removes all control points and i can start from scratch quickly
• 00:38 setting a single control point does nothing, but it's my freedom of choice, same with the 2nd one; i don't have to mess around with predefined spline control points
• 00:48 the difference between always snap and free movement: i can't change the y direction, but I can change x/z and it snaps to wherever i drag the control point
• 00:52 disable snapping

I do understand that Unity has to consider first time users and what not to make the editing easy. But my preference is to have the less clicks the better. I'd like to have freedom of choice. And hence the point: Please do give us the possibility / API to extend your editor and make our own editors

 

I'd like to have just position, nothing else. Messing around with tangents and rotation is something for fine adjustment. And not needed for Catmull-Rom. In my opinion people will mostly use Catmull-Rom. Bezier is just for finer granularity like e. g. roads. My personal preference is Catmull-Rom. If I want something smoother, I just add another control point and not mess around with handles.

Yeah, I know. But I'd prefer to not have ProBuilder in if I don't need it. However if Unity ties ProBuilder tightly to the Splines examples like e. g. for road creation, then that's a different thing.

Please do it asap, don't keep it in a backlog. Or provide a dedicated delete method. It's necessary right from the start for everyone who uses the API.

 

@gabrielw_unity Thanks for the early access, had a few minutes to play with it, so my biggest question is about intersections, is it allowed or in the pipeline to merge 2 or multiple splines and have the mesh generated properly at intersections? @Rowlan did you have a chance to test it out with your Terrain Align solution?

 

I wait for the next package, ie the preview one. I'm pretty sure it'll work though.

 

What editor version do we need? I'm getting The type or namespace name 'ICreateToolbar' could not be found
with 2022.1a13

 

Sounds cool, can't wait to try it out

 

2022.1a15 is finally available, looks like Unity skipped a14. Let's go testing

 

Where should we report bugs?

Code (CSharp):

1. StackOverflowException: The requested operation caused a stack overflow.
2. UnityEditor.Splines.BezierEditableKnot..ctor () (at Library/PackageCache/com.unity.splines@1.0.0-pre.5/Editor/Types/BezierEditableSpline.cs:102)
3. System.Reflection.RuntimeConstructorInfo.InternalInvoke (System.Object obj, System.Object[] parameters, System.Boolean wrapExceptions) (at <96f838c04c564175a85f709a665a953d>:0)

Putting the splines on github would really come in handy, eg for creating issues.

That's an awesome demo scene for showing the features by the way:

 

What's the preferred way to modify a position of a knot? Simple use case with an extension method to set all y positions to 0 results in an error because of the Struct:



ToArray, Transform(...) and the operators each return a copy.

 

Is this package ever going to be backwards compatible, or only 2022.1+? (I'm guessing not because of the new editor features, but thought I would ask anyway).

@Rowlan

Code (CSharp):

1. for (int i = 0; i < spline.Count; ++i)
2. {
3.     var knot = spline[i];
4.     knot.Position.y = 0;
5.     spline[i] = knot;
6. }

 

Thank you, that works for the knots in the inspector and if the Spline isn't in edit mode. Problem is now that there's no update on the knots themselves in the scene in edit mode. Some kind of "refresh" invocation is missing.

 

No idea if this is still the best spot for spline feedback, but @kaarrrllll I thought I would let yall know that right now you can't have a spline field in anything but the root of a

UnityEngine.Object

otherwise the property drawers throw an error.
The reason for this is because you are using a naive implementation to get the Spline value from a SerializedProperty and directly using the property path to get the field and passing the

SerializedObject

's

target

as the object for the

GetField(..)

.

What you need to do is split up the path and walk over the whole think getting each field along the way. I have a implementation myself that supports both arrays/lists and

SerializeReference

if you want to take a look at it.
Github Repo (MIT)
I will most likely submit a bug report tomorrow but I figured most of the additional context and info would be lost, so writing here as well.

 

@gabrielw_unity @kaarrrllll

I tried to create a thread about spline issues on World Building, but it says I wasn't allowed.

I am on beta 9 and macOS Big Sur.

1. When I am editing a spline, I cannot hit the delete key and delete the knot. It just beeps at me.
2. According the the official docs, there is a knot move tool. I only see the knot placement tool. I have to use the regular GameObject move tool to move the knot, but I cannot place a knot on the spline like the docs mention. I have to go into the knot placement tool every time which is a bit tedious especially when that tool doesn't have a shortcut.

Thanks!

 

I really like where things are going with the new Unity splines, I have been waiting for this for years now and it is great to see a team at Unity working on it.

One thing I would like to suggest is to be able to generate a spline based on an image, for instance an SVG file could be imported and the contours of the image could be generated into a spline. Here is a video of a spline asset with this functionality (1:08). This would be really helpful as it would allow users who may not be as quick and proficient in using 3D splines on a computer to quickly to sketch/prototype out a path and then test it out and tweak it in Unity.

Another suggestion, not sure if this is already incorporated, but it would also be great of I could draw some points on a spline and then have some way of selecting those points and generating x amount of knots (or a knot at every x distance) between them. This may be helpful if you want to quickly generate knots at equal distances, say I then want to instantiate on each knot a game object (houses, trees, stones, enemies, etc.), I know they will then be of equal distance from each other.

 

Is there an easy way to modify spline's individual node in runtime ?
Like for example I have a spline with 3 nodes, I want to set each node's position and update the spline in runtime.
Right now in the example scenes, almost all the examples are about pre-defined spline. Only one exception is an example using compute shader, which is over complicated for my need.

This is the code I'm using, way too many step to just set 3 knot's positions.
If we can have an simple method like Spline[0].SetPosition ,and .SetTangent will be convenient.
In runtime, I look at the inspector and noticed the spline's knots do change value, but the spline remain unchanged.

Code (CSharp):

1.                 var s = splineContainer.Spline;
2.  
3.                 var knot = s[0];
4.                 knot.Position = firstPoint;
5.                 s[0] = knot;
6.  
7.                 knot = s[1];
8.                 knot.Position = middlePoint;
9.                 s[1] = knot;
10.  
11.                 knot = s[2];
12.                 knot.Position = dest;
13.                 s[2] = knot;

 

It seems to work on 2021.2 - I just copied the package into my project to try it (had to adjust the path in the code, there's a few instances of the package path for loading icons etc)

Most obvious issue I've spotted is that after editing the spline, the yellow line drawn for the spline gizmo doesn't match the updated spline.



White dots are my quick test of evaluating the spline, yellow line is the spline gizmo - click on the View tool (hand icon) to see both at once.

This seems to happen in 2022.1.0b13, so it's not just an issue with bringing the package into 2021.

(edit: Looks like it needs to set s_SplineCacheTable[spline] to null from the afterSplineWasModified delegate in SplineGizmoUtility.cs, to force the positions to be recalculated?)

 

Nifty package!
Nice to play with and usability is quite solid.

One feature that would be cool for the "Extrude" functionality: Rounded end-caps.
So you can create artistically pleasing things (especially at runtime where ProBuilder is not available) with it. Was planning to randomly generate something like corals.

 

Where you able to find the issues I posted above?

 

No worries!

It was fn + delete, thanks!

 

The knot editor seems to be broken in 2022.2.0a9