Spline Points

Edit the points of regular spline components with the SuperPlacer gizmo — with snapping, Touch&Type, Alt+Drag copies and tangent handles.

Splines are everywhere: roads, fences, cables, Blueprint generators, PCG. The standard editor lets you select a point and drag it with the stock gizmo. SuperPlacer keeps the same order — select the actor, click a point, move it — but moves the point with its own tools: the pivot, the gizmos, snapping, Touch&Type and copies. There is no separate mode for this: it all happens in the usual Transform mode.

Selecting points

1. Select an actor with a spline component, as usual.
2. Click a point of the spline.

The SuperPlacer gizmo moves to the point, and the pivot goes there too. The curve, the points and their selection are drawn by the editor itself, as usual.

• Click — select one point.
• Shift+click — add a point to the selection.
• Ctrl+click — add or remove a point.

Points are selected within one spline: Shift+click or Ctrl+click on a point of another spline starts a new selection on that spline.

Esc ends point editing: the point selection is cleared, the actor stays selected, and the gizmo goes back to the actor. A click away from the points, the tangents and the curve does the same — even on another actor. Point editing is one step above the actor, so the first click takes you back to the actor, and only the next click selects another actor. If a tangent was selected, the first click away deselects only the tangent. Leaving point editing is a step of its own in the undo history, so Ctrl+Z brings the point selection back.

The component level

If an actor has several splines — for example, a Blueprint with two spline components — there is one more step between the points and the actor: the spline itself. The first click away from the points (or Esc) selects the spline the points belonged to. The SuperPlacer gizmo moves to the start of that spline and moves, rotates and scales it as a whole inside the actor — just like a selected component in the standard editor. The Details panel shows the selected component. The next click away (or Esc) takes you back to the actor, and a click on any point selects that point right away. You can also select a spline component in the Details panel — SuperPlacer picks it up. Each move between these levels is a step of its own in the undo history: Ctrl+Z takes you back to the previous level.

At the component level Alt+drag doesn't make a copy, it just moves the spline, and Delete doesn't delete the component (delete it in the Details panel if you need to). Edit Pivot (C) builds its box around the component itself. An actor with one spline, and a spline that is the actor's root, don't have this level: a click away from the points takes you straight back to the actor.

F brings the selected points into view: one point close up, several points so that they all fit. With no points selected, F works as the editor's usual Focus Selected.

Moving, rotating and scaling

Points move with the same gizmos as actors: Translate, Rotate, Scale (W, E, R), and in Quick mode.

• Moving shifts the point, and its tangents go along. The point type stays: a Curve (Auto) or Curve Clamped point keeps fitting its tangents to its neighbours by itself.
• Rotating turns the tangents together with the point. Rotating around the tangent changes the point's roll — the direction of its "up".
• Scaling changes the length of the tangents along the axes of the chosen coordinate system.

After a rotation or a scale the point becomes a Custom Tangent point — just like in the standard editor. Linear and Constant points keep their type whatever the gesture.

With several points selected, they rotate and scale as a group around a shared pivot.

In the Local coordinate system the gizmo faces along the spline; with several points, the axes come from the last selected one. The X axis runs along the tangent at the point. Where there is no tangent (a Constant point or a zero-length tangent), X points to the next point, and at the last point of an open spline it carries the line forward. So a point on a straight run is easy to slide along the line by the X axis. After a gesture the axes follow the new shape of the curve. Ctrl+` switches the systems, as for actors (see Coordinate Systems).

While you drag the gizmo, the spline updates live. When you release the mouse, the editor gets the whole edit at once — as after a stock tool: a Blueprint reruns its construction script, and dependent systems update.

Inserting a point

Hold Ctrl and bring the cursor to the curve — a point shows on it where the new one will go. Click without releasing Ctrl: the point is added there and becomes the selection right away, so you can move it with the gizmo at once. An insert is one Ctrl+Z step. On a closed spline you can also insert a point into the closing segment.

• On a curved segment the shape of the curve doesn't change: the new point and its neighbours become Custom Tangent points with tangents that repeat the old curve.
• On a Linear or Constant segment the new point gets the same type, and the neighbouring points don't change.
• The roll and the scale of the new point are the average of its neighbours.

New points with Alt+Drag

Alt+Drag on the gizmo creates a copy of the selected points and drags it:

• on the end point of an open spline, the copy becomes the new end — the spline gets longer;
• on a middle point, the copy lands next to the original — the spline gets a new point that you carry away right there.

The copy gets the type of the original point. A right click in the middle of the gesture cancels the copy.

Copies from the Touch&Type window and repeating the last copy with Alt+Enter work for points too — see Copies.

Deleting points

Select points and press Delete. It's one step in the undo history.

Every spline must keep at least two points: if a delete would leave fewer, SuperPlacer doesn't do it.

Tangents

A selected point shows its tangent handles — the incoming one and the outgoing one. Linear and Constant points have no handles: their tangents are computed by the engine.

1. Click a tangent handle — it gets selected, the point's gizmo hides, and a small tangent gizmo appears on the handle.
2. Drag the handle by an axis or a plane of that gizmo — or by the handle itself.

Modifiers while dragging:

• Shift — only the length of the tangent changes, its direction stays;
• Alt — the tangents break apart: the second one no longer repeats the first. The break is remembered.

Without Alt the second tangent of a smooth point mirrors the first one. After a tangent edit the point becomes Custom Tangent. A click on the point itself deselects the tangent. A right click while dragging cancels the drag.

The point menu

Right-click a selected point to open the menu:

A right click away from the point — on a gizmo axis, for example — opens the usual gizmo menu.

Point roll

Roll sets where the point's "up" looks — for example, how a road surface lies in a turn. To change the roll, turn the point with the Rotate gizmo around its tangent.

To type an exact roll, use the Touch&Type window: when you rotate one point, it has a fourth field, R — the angle in degrees from the automatic position. Zero is the automatic roll.

Houdini Engine splines

If Houdini Engine is installed in the project, curves on HDA actors are edited the same way.

• Points are selected with the Houdini Engine tools themselves; once a point is selected, the SuperPlacer gizmo appears on it.
• You can move points with the gizmo, Touch&Type and Alt+Drag. Rotating and scaling a single point doesn't affect the curve: Houdini curves have no tangents.
• The HDA recooks once, when you release the mouse. When you type numbers, the recook waits half a second after the last change.
• Copies from the Touch&Type window are turned off for Houdini points: the value you type just moves the point.
• Points are deleted by Houdini Engine itself.