Dimension Snapping and Hover

Dimension endpoints in VisionPlan have two distinct snap behaviours and one hover affordance. Knowing which one is firing at a given moment makes precision placement much faster — you stop wondering whether the endpoint is committed to a wall corner or just floating near it.

This reference covers:

1. Click-time snap — where the endpoint lands when you click to place or reshape a dim.
2. Drag-time snap — what the pulsing green indicator means while you're reshaping a dim endpoint.
3. Hover affordance — the orange ring that tells you "this endpoint is grabbable" before you commit.

The behaviour applies to both tape dims (placed by the Tape Measure tool in Dimension line mode) and segment dims (placed by the Dimension tool). The hover affordance specifically watches endpoints on both types.

Click-time snap — placing a new dim

Tape dims (Tape Measure tool, Dimension line mode) and segment dims (Dimension tool) snap differently when you click to place them. Worth knowing up front so the right tool fits the placement you're after.

Tape dim placement uses the full snap target chain — the same one the wall tool uses. Targets include:

• Wall endpoints — wall corners and join nodes.
• Fixture corners — the four corners of every fixture's bounding rectangle.
• Tape dim endpoints — both ends of every placed tape dim.
• Measurement marks — diamonds dropped by the Tape Measure tool.
• Pin guides — point-style guides.
• Horizontal and vertical guides — line-style guides.
• Tape dim lines — anywhere along a placed tape dim line.
• Wall lines — anywhere along a wall (for T-intersection placements).

Hold Ctrl while clicking a tape dim point to bypass snap for that one click — the click commits at the raw cursor position. Between the first and second tape dim click, the second endpoint also gets a soft horizontal / vertical lock — within about seven degrees of straight, the segment snaps to a clean H or V. Ctrl bypasses that lock too.

Segment dim placement uses a tighter point-only snap: wall endpoints, fixture corners, tape dim endpoints, and measurement marks. Wall-line projection, tape-dim-line projection, and H/V guide lines aren't part of the segment dim snap chain in v1 — if you need to snap onto the middle of a wall, place a tape dim instead. The segment dim placement also doesn't honour Ctrl-bypass or the H/V soft lock — those are tape-dim-only behaviours in v1.

Drag-time snap — reshaping a dim endpoint

Once a tape dim is on the canvas, you can grab either endpoint in the Select tool and drag it to a new location. The endpoint follows the cursor, but the resolved snap target is computed using a tighter, screen-space tolerance — not the same as the click-time snap above.

Two stages:

1. Node snap — within roughly 12 screen pixels of a wall endpoint or fixture corner, the endpoint snaps to that node.
2. Wall-line projection — within roughly 8 screen pixels of a wall line (and not within node range), the endpoint projects onto the wall, sliding along it as the cursor moves.

The thresholds are screen-space, not world-space. Zoom out, the world distances grow; zoom in, the world distances shrink. The on-screen "feel" stays constant. (The old behaviour was a fixed 20 mm world threshold, which at low zoom resolved to many screen pixels and made the indicator fire constantly. The screen-space version was added in version 1.0.0-rc.3+13 to fix that.)

The pulsing green snap indicator

While you're dragging a tape dim endpoint and the cursor is within range of a snap target, a pulsing green circle appears at the snap target. That circle is the visual confirmation: release the mouse / lift the finger now and the endpoint commits to the marked point, NOT where the cursor actually is.

If no node or wall line is in range, the indicator hides — you're dragging freely and the endpoint will land where the cursor releases.

The indicator is the same visual the Tape Measure tool uses while you're hovering for the second click. Same colour, same pulse — same meaning: "this is where it'll go."

Hover affordance — the orange ring

In the Select tool on desktop, hovering the cursor close to a tape dim or segment dim endpoint shows a small orange ring with a filled centre at the endpoint. The ring tells you "this endpoint is grabbable" — start dragging now and you'll reshape THAT endpoint, not move the whole dim.

The ring fires:

• When you're in the Select tool (not while drawing or while another tool is active).
• When you're not already dragging another tape dim endpoint or moving a tape dim.
• When the cursor is within roughly 10 screen pixels of the endpoint.

If you're outside the hover radius, the ring doesn't appear and starting a drag will move the whole dim instead. The ring is a precision cue: it disambiguates "drag the dim around" from "drag this corner of the dim to a new spot."

The hover ring is desktop-only. Mobile uses a tap-to-select flow rather than hover, so the affordance isn't shown there.

The ring colour (orange) is intentionally distinct from the pulsing green snap indicator. Orange = "you could grab this now." Green = "this is where it'll snap to during the drag."

Reshape vs translate — the rule

After a tape dim is placed, dragging it does one of two things:

Start-of-drag position	Result
Within the endpoint hover radius (~10 px)	Reshape — only that endpoint moves; the other endpoint stays put.
Anywhere else on the dim line or label	Translate — the whole dim slides with the cursor; both endpoints move together.

The orange hover ring is the visual flag for the first case. If you see the ring, your drag will reshape. If you don't see the ring, your drag will translate.

Mobile behaviour

The hover ring doesn't fire on mobile (no hover state). To reshape a tape dim endpoint on mobile:

1. Tap the tape dim to select it.
2. Use the entity panel / property sheet to adjust the dim's properties, or
3. Drag the endpoint directly — the drag-time snap and pulsing green indicator both fire on mobile.

Snap target reference (Settings → Snapping)

The endpoint snap is just one consumer of the project's snap target list. To tune the behaviour, open Settings → Snapping:

• Master switch + sensitivity (Basic tier) — global toggle and a low/medium/high sensitivity multiplier.
• Per-target toggles (Advanced tier) — individual on/off for tape dim endpoints, wall endpoints, fixture corners, etc.
• Per-tool overrides (Expert tier) — different snap behaviour per tool. The tape measure can have its own snap set distinct from the wall tool.

Holding Ctrl while clicking bypasses snap for one point regardless of settings.

Tips

• If the pulsing green indicator is firing on the wrong target, zoom in. Screen-space thresholds tighten in pixel terms but loosen in world terms — at high zoom you'll see only the snap target you actually want.
• If the orange hover ring is hard to see against busy geometry, zoom in. The ring scales with zoom so it stays a constant pixel size on screen.
• The wall-line projection (the second stage of drag-time snap) is what lets you slide a dim endpoint along a wall without it grabbing onto every wall corner along the way. Useful when you're locating a dim halfway down a long wall.
• A tape dim endpoint snapped to a wall-line projection is NOT locked to the wall — drag again later and it moves freely. The snap only applies at commit time.