Feedback At which point in time will Unity add Splines?

Thanks for the response. I was hoping for B-Splines as they're easier to work with and scale better than the classic Bézier curves. (Of course I'm assuming that you have the classic Bézier algorithm. People have been modifying it a lot, so what I'm saying might not even apply to what you guys have been cooking up.)
In any case, I'm looking forward to those tools.

 

I know I'm late to the party and I don't really have too much concrete expectation other than we need to be able to evaluate a spline in runtime with proper interpolated (or interpolate-able) rotations and roll. Otherwise how can we do a barrel roll proper, straight from Star Fox in our cinematics...

I quite like the premise of the extendibility of the splines in Procedural Worlds' Gena Pro. Here's a short video about it:

Spoiler: Procedural Worlds Spline Extention

 

2021.2 Beta got realeased with no mention of Splines. So 2022 it is?

 

Splines are useful for almost everything. One use that doesn't really get mentioned is for audio. Every project in a DAW is filled with splines. Every time you need to automate a parameter you use a spline of some sort. Envelopes, LFO's, randomization, custom curves.. Filters, compression, everything is displayed as editable/semi editable curves.

Right now I am using animation curves for when I need to automate a parameter, but these particular types of beziers are very difficult to normalize and constrain within a range or push to a different range if you aren't the one drawing them. You also can't specify their requirements, so that when someone else is drawing a curve, they conform to the standard that you expect.

So, for audio, I'm really just looking for a 2D spline tool to replace the audiocurve. Having the ability out of the box to normalize or remap to range would be very useful. Having the ability to force requirements, like forcing a user to have a certain number of points on the curve, or the ability to force that the curve has the ability to be looped (start.y = end.y), or to define an end node for example that always has a y value of zero, but can be moved along the x axis, as long as it's x value is greater than the second last node. Being able to define contraints like that for the person using the curve tool would be very useful.

I'm looking for this to be available in the inspector and in visual scripting or other graph solutions that unity releases, because that's where audio is headed. If it replaces audiocurves in the audiosource settings at some point, that would be nice too.

 

That sounds awesome and definitely worth the wait then, thanks for the update!

 

This is probably a long shot, but since it's a package, are there any plans for it to be usable in 2020 LTS or 2021 LTS? We're really really excited about this feature, but not so excited about potentially not being able to use it until the year 2023 (Unity 2022 LTS).

 

Then I assume the 2021 LTS version will not support it?

 

Can't wait to give it a crack, exciting stuff. Is there documentation available for us to read up on and get excited hehe

 

That's good to hear, thank you and the team for your hard work.

My only request is that there be some display option to draw the forward of the spline. Lots of spline packages don't do this and it's very annoying!

 

It would be cool, if we would be able to add custom data to Splines and Iterpolate them across the Spline.

 

Great news! looking very much forward to try it out

 

So here's some things I've been thinking about with regards to spline editing from working with the SpriteShape splines, where SpriteShape has gotten things very, very wrong.

The big one is that the SpriteShapeEditorTool aggressively caches everything about the Spline. So if you have it active and change any of the Spline data, you either have to use a bunch of reflection and mess with it's internal data, or force it to deactivate, otherwise there's a disconnect between the data and the editor.

So the new Splines should for sure handle it if we change the data through script when editing the Spline. Preferably it just shouldn't be caching any data.


The SpriteShapeEditorTool also doesn't give out any of it's data. So if you want to create tools that interacts with the selected points, you have to reflect a ton - reflect to get at EditorToolManager.activeTool, and then reflect through an overengineered horror to get at a ScriptablePath wrapper around the cached data that also happens to hold a selection abstraction.

So the new Splines tool should be able to just tell us which control points are selected, so we can build tools around that. Examples of tools that need this is stuff like "split this spline into two parts, with the selected points in one of the parts" or "set the tangents of the two selected control points such that they outline a circle".
In general, EditorToolManager.activeTool should also be made public, so we can interact with it.


The SpriteShape also has an unconventional data layout. Every single article and paper on (cubic) Bezier curves has the four points p0, p1, p2 and p3, where p0 and p3 are the positions of the start and end, and p1 and p2 are the control points (or tangent points). SpriteShape instead has tangent offsets, so the data we get out is p0, (p1 - p0), (p2 - p3) and p3. So whenever we want to do anything with tangents, (including calling Unity's own Bezier API's!), we have to add p0 or p3 to the tangents.
This has probably been done to make things easier when moving the control points, as you then don't need to also move the tangents. But this makes all code interacting with this very standard thing be non-standard.

So the new Splines should for sure give us the data in the standard way, so we can just plug it into any known Bezier formula or library.

 

In my opinion, it would be best to be able to create custom spline classes or structs with data variables.
Then you change the variables on each knot independently via the Inspector.
With numeric variable types (float, vectors, color, ...) it would be cool if they automatically interpolate between knots.

For example:
Let's say you want to create a road with a few knots.
And you want certain sections of the road to be bumpier or wider than others.
In the mesh generation script, you simply generate a structure with your custom data type and get the information you need at a specific point on the road (RoadWidth, NoiseStrengh, UVScale, etc.)

Also it would be cool if you can select the Splinetype
(Linear, Bezier, Cubic, Akima, B-Spline)

Without starting a discussion, Cinema 4D has the best implementation for splines.
A perfect balance between being simple but incredibly flexible.

 

Any updates on the ETA for the experimental drop yet ?
We require a spline solution ourselves right now but are well aware that the upcoming preview release of the spline system is not meant for production. Therefore, we are in the process of building our custom tool/solution which we would like to be close enough to the one Unity is building to ensure a seamless transition in the future. Access to the preview release of Unity's spline tool would of course make this a lot easier.

 

I would definitely like to be on the early-early list

 

Any news yet?

 

In a 2D workflow, would the extra functionality of the upcoming Splines somehow tie into the splines in Sprite Shape that already exist? I have been looking forward to an upgrade to Sprite Shape. Maybe Splines will fill the gap of the missing features in Sprite Shape?

 

It's been 28 mins though

 

I'm gettings this error:

Code (CSharp):

1. [Package Manager Window] Cannot perform upm operation: Unable to add package [com.unity.splines]:
2.   Package com.unity.splines@0.1.0-preview.1 has invalid dependencies or related test packages:
3.     com.unity.coding (dependency): connect ETIMEDOUT 35.238.21.138:443 [NotFound].
4. UnityEditor.EditorApplication:Internal_CallUpdateFunctions ()
5.  

EDIT: working now

 

Getting these errors on the sample scripts:

Code (CSharp):

1. Assets\Samples\Splines\0.1.0-preview.1\Spline Examples\Tools\SpeedHandle.cs(34,57): error CS1061: 'NativeSpline' does not contain a definition for 'Length' and no accessible extension method 'Length' accepting a first argument of type 'NativeSpline' could be found (are you missing a using directive or an assembly reference?)
2.  

 

Just some initial suggestions:

• Add a way to enter precise values for points in a intuitive way (like highlighting the node element in the array which is currently selected)
• Snapping (for position, rotation, and scale (in Bezier mode))
• Ability to rotate selected points around a pivot (If I select multiple points currently and rotate them using rotation handles, they just rotate around their own points, instead I may want to rotate these points around another pivot, so a way to define that pivot would be helpful in many cases)
• When not edit the spline (i.e, selecting gameObject instead of spline in tools overlay) it would be helpful to have some better indicator that a spline is available for editing, currently anyone could miss it.
• I think you do have support for multiple splines on a single gameObject so they could appear by different names in tools overlay?

This looks like a promising system so far

 

Just found out that this isn't possible right now, so the way it's implemented currently we would edit all the splines at once present on a given gameobject with components implementing "ISplineProvider", What are your plans fir systems that require multiple splines on a single game object?
Having all the splines visible at once with no distinction between them would be a problem I think

EDIT: Undo doesn't seem to be supported yet for values other than the transformation values, like in the Follow spline Demo (the one with procedural road) changing scale doesn't get registered to Undo system

In local mode the handles don't align with nodes currently, they are always world aligned

 

I didn't mean branching and merging (although would be required as well), what I meant was what if we need two splines for completely unrelated reason on a single component, what would we do then?

 

Also, some instability issues I found:
After editing any points on the spline in this demo, somehow tangents seem to get mis-aligned or something because the meshes get weird(it happens on all the road demos)
Example screenshot:
before editing:

After editing even a bit (like moving the position handle a bit):

 

Currently having multiple splines looks like this:


(PS: even though closed is ticked on the component you can see the second spline is open, if I remove a node directly from the inspector instead of the scene view, it doesn't seem to work currently)

Get this error sometimes when deleting a node in scene view (Spline mode)

Code (CSharp):

1. ArgumentException: Offset and length were out of bounds for the array or count is greater than the number of elements from index to the end of the source collection.
2. System.Collections.Generic.List`1[T].RemoveRange (System.Int32 index, System.Int32 count) (at <8457b1d8f38645bdb69ed3fccdb8a2ba>:0)
3. UnityEngine.Splines.Spline.Resize (System.Int32 newSize) (at Library/PackageCache/com.unity.splines@0.1.0-preview.1/Runtime/Spline.cs:294)
4. UnityEditor.Splines.SplineConversionUtility.ApplyEditableSplinesIfDirty (UnityEngine.Object target) (at Library/PackageCache/com.unity.splines@0.1.0-preview.1/Editor/Utilities/SplineConversionUtility.cs:136)
5. UnityEditor.Splines.SplineConversionUtility.ApplyEditableSplinesIfDirty (System.Collections.Generic.IEnumerable`1[T] owners) (at Library/PackageCache/com.unity.splines@0.1.0-preview.1/Editor/Utilities/SplineConversionUtility.cs:108)
6. UnityEditor.Splines.SplineMoveTool.OnToolGUI (UnityEditor.EditorWindow window) (at Library/PackageCache/com.unity.splines@0.1.0-preview.1/Editor/Tools/SplineMoveTool.cs:59)
7. UnityEditor.EditorTools.EditorToolManager.OnToolGUI (UnityEditor.EditorWindow window) (at <211b71fdae8c4742b932a3743a0c1b4d>:0)
8. UnityEditor.SceneView.DefaultHandles () (at <211b71fdae8c4742b932a3743a0c1b4d>:0)
9. UnityEditor.SceneView.DoOnGUI () (at <211b71fdae8c4742b932a3743a0c1b4d>:0)
10. UnityEditor.SceneView.OnSceneGUI () (at <211b71fdae8c4742b932a3743a0c1b4d>:0)
11. UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
12. UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
13. UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
14. UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Boolean canAffectFocus) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
15. UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUIRaw (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
16. UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUI (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
17. UnityEngine.UIElements.KeyboardEventDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
18. UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
19. UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
20. UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
21. UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
22. UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
23. UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
24. UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
25. UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <15d215270c7e4b6eb337b3c8f8615af9>:0)
26. UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <a1ed2b7adea746d4847b370351b77396>:0)
27.  

 

Where? In this Beta section or the World Building section? I rather suggest that Unity creates a new dedicated section for Splines. This will escalate in usage

 

Would it be possible to get a tag for Splines like there is for ProBuilder and Terrain? Those are very helpful.

 

change Length to GetLength() in SpeedHandle.cs

 

Speaking of latest, is there a github repo for the Splines? It would be very helpful for those of us who don't want to wait 2 weeks for a fix to go live.

 

I created a first time user feedback thread, in case anyone wants to join:

https://forum.unity.com/threads/splines-feedback.1190464/

 

Sure, I wrote it on top of the very first post. If it would be confusing for others I don't mind if the entire thread gets locked or deleted. Looking forward to the preview release.

 

Hey, @gabrielw_unity would be cool to have spline deformer example among others