Sample Nearest Surface

PCGEx | Sample : Nearest Surface

Sample information from the nearest mesh collision

The Sample Nearest Surface node performs spherical queries to find the closest point on nearby simple colliders within a set radius, sampling spatial data and actor references from overlapping surfaces and applying tags based on query results.

Points that will be used as origin for finding & sampling the nearest surface

Point Filters

Points filters used to determine which points will be processed. Filtered out points will be treated as failed sampling.

Actor References

Points containing actor references, if that mode is selected.

Out

In with extra attributes and properties

The Sample Nearest Surface node allows you to perform a single per-point spherical query to find the closest point on the closest overlapping collider.

Please note that this node is not tracking actors. If you change the sampled environment you will need to manually regenerate the graph unless something else already triggers a refresh in editor.

Under the hood this find the closest point on the closest collider – this feature is only supported for simple collider and won’t work on complex ones.

details/sampling-nearest-surface/lead.png

Properties

Property	Description
Settings
Surface Source	Select where you want to read surfaces from: either `All` (revealing additional actors picking parameters), or `Actor References`, to sample only specific actors.
Actor Reference	Attribute to read actor reference from the Actor References input data.
Max Distance	Maximum radius of the overlapping sphere
Local Max Distance	If enabled, fetches the overlap sphere radius on a per-point basis using the specified attribute.

Outputs

Outputs are values extracted from the overlap query, and written to attributes on the output points.

Output	Description
Generic
Success `bool`	TBD

Spatial Data
Location `FVector`	TBD
Look At `FVector`	TBD
Normal `FVector`	TBD
Distance `double`	TBD
Is Inside `bool`	TBD

Actor Data
Actor Reference `FSoftObjectPath`	TBD
Phys Mat `FSoftObjectPath`	TBD

Extra properties

Forwarding

Data forwarding settings from the Actor References input points, if enabled.

“Forwarding” settings lets you pick-and-choose which attributes & tags carry over from some data to another.

Property	Description
Enabled	Whether attribute forwarding is enabled or not.
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.

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.

Tagging

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

Tag	Description
Has Successes Tag	If enabled, add the specified tag to the output data if at least a single query has been successful.
Has No Successes Tag	If enabled, add the specified tag to the output data if all queries failed.

Note that fail/success tagging will be affected by points filter as well; since filtered out points are considered fails.

Collision Settings

These settings drive which objects will be ignored during the collision checks.

Property	Description
Trace Complex	Whether to collide against complex or simple collision. Note that this setting may not be supported everywhere.
Collision Type	The type of collision check. Can be one of: -`Channel` -`ObjectType` -`Profile` The selected mode changes which settings are available.
Collision Channel	Lets you pick the collision channel to check against.
Collision Object Type	Lets you pick the object type to check against.
Collision Profile Name	Lets you set a custom profile name to check against.
Ignore Self	If enabled, will ignore the current PCG Component’ actor owner.
Ignored Actor Selector	Vanilla PCG Actor Selector.

Advanced

Property	Description
Process Filtered Out As Fails	If enabled, mark filtered out points as “failed”. Otherwise, just skip the processing altogether. Only uncheck this if you want to ensure existing attribute values are preserved. Default is set to true, as it should be on a first-pass sampling.