Path × Path Crossings

PCGEx | Path × Path Crossings

Find crossings within & against other paths.

The Path × Path Crossings node detects intersections between path segments, either within the same path or against others, blending attributes from intersecting points and providing detailed control over how crossings and blending are handled.

Paths

Paths which edges will be checked for crossings

Can Cut Conditions

Filters used to determine whether a segment can "cut" other segments

Can Cut Conditions

Filters used to determine whether a segment can be "cut" by cutter segments

Paths

Paths with additional points & informations

Table of content

Properties
- Intersection Details
Blendings
- Blending
- Cross Blending
  - Crossing Carry Over
  - Crossing Blending
Outputs
- Tagging

The Path × Path Crossings find all paths segments intersections either against all other inputs, or only against itself. Created intersection can capture attributes from the the foreign path’ point, amongst other useful things.

details/paths-solidify/lead.png

Properties

Property	Description
Closed loop
Scope	The scope/selection of input data that are to be processed as closed paths or not. -`All` processes all input as selected below. -`All but tagged` inverts the scope based on tags. Default is, all paths are considered open, unless they are tagged with `ClosedLoop`.
Closed Loop	Whether to consider input data that are part of the scope as closed loop or not.
Comma Separated Tags	Tags to check for. Any match uses the inverse of the above value.

Self-intersection Only

If enabled, input paths will only check for crossing against themselves, as opposed to against every other input path.

Intersection Details

Property	Description
Enable Self Intersection	If enabled, a cluster will test if intersection exists against itself. Otherwise, only check against other clusters.

Tolerance
Tolerance	Uniform tolerance. This represent the radius within which elements will be considered in fuse range.
Min Angle	If enabled, only considers edges to be intersecting if their angle is greater than the specified value.
Max Angle	If enabled, only considers edges to be intersecting if their angle is smaller than the specified value.

Outputs
Crossing Attribute Name `bool`	If enabled, flag the edges’ intersection point.

Blendings

Blending on this node happen in a very specific order:

First, crossing point property are calculated as a blend between the start & end point of the segment that’s being cut.This considers internal properties & attributes only.
Then, if enabled, cross-blending is processed: this pass blends attributes from the foreign crossing data to bleed onto the crossing point.This only considers external properties & attributes only.

Blending

Cross Blending

If there is an overlap, cross-blending will overrides any previously blended values.

Crossing Carry Over

“Carry over” settings lets you pick-and-choose which attributes & tags carry over to the new data.

Property	Description
Preserve Attributes Default Value	If enabled, the node will attempt to create attributes on the data in a way that preserve the original, underlying default value of the attribute. This can be critical in order to identify which data originally belonged to which, as well as properly initializing flags to a desirable default.
Attributes	Lets you pick and choose which attributes to keep or dismiss.
Tags	Lets you pick and choose which attributes to keep or dismiss.

Both Attributes & Tags share the same string-based filters.

Note that the filters look for a single valid match amongst the list; you cannot create and/or conditions.

Filter Details

Property	Description
Filter Mode	Chooses how the filter operates. - `All` let everything pass. - `Exclude` filters out the result of the filter. - `Include` only allows the items that pass the filters.
Matches	Lets you define a list of checks pairs: a string value, and a `Match Mode`.
Comma Separated Names	Easy to override, lets you specify a list of comma-separated names. The only caveat is that you can only pick a unique match mode used for each entry.
Comma Separated Names Filter	Which filter will be used along the Comma Separated Names.
Preserve PCGEx Data	Most of the time you’ll want to leave it to its default value. It ensures `PCGEx/` prefixed data are not captured by the filter.

Filter Modes

Mode	Description
Equals	Checks for strict equality of the filtered value and the associated string.
Contains	Checks if the filtered value contains the associated string.
Starts With	Checks if the filtered value is prefixed with the associated string.
Ends With	Checks if the filtered value is suffixed with the associated string.

Crossing Blending

See Blending

Outputs

Output	Description
Crossing Alpha `double`	Write the normalized position (alpha) of the crossing.The alpha of a crossing is a `0..1` value representing where it sits between start and end point of the original segment.
Crossing Orient Axis	If enabled, lets you pick a local transform axis of the crossing point to orient in the crossing’ segment direction.
Cross Direction `FVector`	Similar to the option above, only writes the crossing segment’ direction to an attribute instead of applying it to the point rotation.

Tagging

Some high level tags may be applied to the data based on overal intersections results.

Tag	Description
Has Crossings Tag	If enabled, add the specified tag to the output data if at least a single crossing has been found.
Has No Crossings Tag	If enabled, add the specified tag to the output data if no crossings have been found.

Note that crossing detection tagging will be affected by points filter as well; since filtered out points are omitted from processing.