Using QGIS vertex editor? [closed]

Question

I'm having two main problems:

1. When hovering over a map with multiple layers, even though I only have one layer editable and visible, I am seeing all the nodes of all layers show up as red dots when hovering over the map canvas, making it impossible to select nodes of the layer I am actually working on. Can this behaviour be turned off? It may be related to the option for editing only the selected layer, but I can't actually find this under Settings | Options and maybe it is no longer there? It seems that I can only edit the selected layer anyway, so why do the dots need to show up at all? I have checked snapping settings and have the new topological editing option turned off.

2. I am finding editing of polygons extremely difficult and clunky now. It is now not possible to move a node with a simple mouse drag. It seems that it is now necessary to drag a new node from a vertex to the new position, then delete the old node. Selection can be done by keyboard or mouse, but deletion can only be done by hitting delete on the keyboard, so the whole procedure takes several seconds. However, what usually happens is that when attempting to create a new node, several connected vertices do move at once even if no nodes are selected. Other strange things are also happening.

Answer 1

In QGIS 3.0, the vertex tool (same as node tool from QGIS 2.x) works a bit differently. Whether this is an improvement or not is a matter of opinion. It certainly takes a bit of getting used to.

Moving a vertex

• 2.x: Click on a vertex or segment to enable vertex editing for that feature. Click on vertex you want to move. Without releasing the mouse, drag it to new location.

• 3.0: Hover over a vertex to enable vertex editing for that feature. Click on a vertex to select it. Release the mouse button, and the selected vertex will follow the cursor. Click again to place the vertex.

Moving a segment (basically the same as moving a vertex)

• 2.x: Click on a vertex or segment to enable vertex editing for that feature. Click on segment. Without releasing the mouse, drag it to new location. Release mouse.

• 3.0: Hover over a segment to enable vertex editing for that feature. Click on a segment to select it. Release the mouse button, and the selected segment will follow the cursor. Click again to place the segment.

Adding a new vertex

• 2.x: Double-click on a segment.

• 3.0: Two options

1. Double-click on a segment to add a new vertex. The new vertex starts out selected and stuck to the cursor. Click a third time to place the vertex.

2. When hovering over a segment, there is an X in the middle of the segment. Click on the x to add a new vertex. The new vertex starts out selected and stuck to the cursor. Click a third time to place the vertex.

Deleting a vertex

• Both versions: Click and drag to select one or more nodes. Use delete key (on keyboard) to delete selected nodes.

Note: In 3.0, the node tool will only edit features in the current (active) layer. If you have a feature selected, the node tool will only edit that feature.

In 3.0, hover over features to see their nodes highlighted in red. This shows nodes for features in all layers in edit mode. Layers that are visible and not in editing mode won't be highlighted. Layers that are not visible will be highlighted - this does seem like a bug.

Update (Nov 2018): This bug is fixed in QGIS 3.4, and a new feature added. You now have a choice between Vertex Tool (All Layers) and Vertex Tool (Current Layer). Non-visible layers will not be highlighted in either mode.

Another note: I've always thought that "node" and "vertex" were synonyms. Many people use these terms interchangeably. However, there is a difference, and it's discussed in detail here.

See also: QGIS 3.0.0 Changelog: overhaul of vertex tool

Github: improved node tool

Answer 2

I was having this issue but I noticed that 'Enable snapping by default' was checked on under the 'Digitizing' options. When unchecking this, the problem went away.