The GridSliceResizerComponent is a versatile tool designed to maintain the proportions of specific areas of 3D meshes while allowing others to stretch during scaling. This component should replace the static mesh component, rather than being used in conjunction with it.

The concept of the GridSliceResizerComponent is similar to the popular 9-Slice-Scaling technique used in 2D graphics, which keeps the borders of sprites unstretched while the inner rectangle is stretched. In essence, the GridSliceResizerComponent is a 27-Slice-Scaler for 3D meshes.

The component operates by dividing the bounding box of a 3D mesh into 27 cuboids, as illustrated below. Not all cuboids are visible in this picture. Only the ones that are front facing: +-----+-----------+-----+ /_____/___________/_____/| /_____/___________/_____/|| / / / /||| +----+-----------+-----+ ||| | A | B | C |/||| +----+-----------+-----+ ||| | | | | ||| | D | E | F | ||| | | | |/||/ +----+-----------+-----+ |/ | G | H | I | / +----+-----------+-----+

The scaling behaviour is as follows (assuming all other faces of the bounding box are divided as the front facing one):

Center Cuboid (E): Vertices within this cuboid stretch on two axes (Y, Z). Corner Cuboids (A, C, G, I): These cuboids do not stretch on any axis. Middle Cuboids (B, H): These cuboids stretch horizontally but not vertically. Middle Cuboids (D, F): These cuboids stretch vertically but not horizontally.

The slicing areas are defined by the SlicerPivotOffset and BorderXNegative, BorderXPositive, etc. These border values range from 0 to 1 and extend from the mesh's pivot (which may be offset by SlicerPivotOffset) to the maximum or minimum of the bounding box's axis. If all borders are set to 1, the mesh will stretch like a regular mesh during scaling. If set to 0, no stretching will occur. Typically, you'll want the pivot in the middle of the mesh and the borders set to around 0.8.

You can visualize the borders and pivot in the Actor editor preview using bDebugDrawPivot, bDebugDrawBorderX, etc.

This component is only compatible with static meshes that have CPU access enabled. Ensure you enable CPU access in the static mesh editor.

Constructors

UMRUKGridSliceResizerComponent ()

Signature

UMRUKGridSliceResizerComponent::UMRUKGridSliceResizerComponent()

Fields

bGenerateCollision : bool	Whether or not a collision mesh should be created for the static mesh. Signature bool UMRUKGridSliceResizerComponent::bGenerateCollision
BorderXNegative : double	Slice border for the negative X axis. Signature double UMRUKGridSliceResizerComponent::BorderXNegative
BorderXPositive : double	Slice border for the positive X axis. Signature double UMRUKGridSliceResizerComponent::BorderXPositive
BorderYNegative : double	Slice border for the negative Y axis. Signature double UMRUKGridSliceResizerComponent::BorderYNegative
BorderYPositive : double	Slice border for the positive Y axis. Signature double UMRUKGridSliceResizerComponent::BorderYPositive
BorderZNegative : double	Slice border for the negative Z axis. Signature double UMRUKGridSliceResizerComponent::BorderZNegative
BorderZPositive : double	Slice border for the positive Z axis. Signature double UMRUKGridSliceResizerComponent::BorderZPositive
Mesh : class UStaticMesh *	The static mesh to slice. Make sure to enable CPU access on it. Signature class UStaticMesh* UMRUKGridSliceResizerComponent::Mesh
ScaleCenterMode : uint8	This parameter determines whether the center part of the object should be scaled. If set to false, the center vertices will remain stationary. This is particularly useful when you want to maintain the proportions of certain geometrical features in the center part, such as a doorknob. By keeping the center vertices in place, you can avoid unwanted stretching effects, resulting in a more visually appealing outcome. However, it's important to note that for a convincing visual effect, the texture applied to the object should also not stretch. If you encounter issues with texture stretching, consider adding an additional loop cut. This can help maintain the texture's proportions and prevent it from distorting. In case the mesh gets scaled down and some of the center vertices fall outside of the scaled down center all vertices that are inside the center will be scaled down uniformly. Signature uint8 UMRUKGridSliceResizerComponent::ScaleCenterMode
SlicerPivotOffset : FVector	How much the meshes pivot should be offset when applying the slice borders. Signature FVector UMRUKGridSliceResizerComponent::SlicerPivotOffset

Friend Declarations

FMRUKGridSliceResizerSpec : class

Signature

friend class FMRUKGridSliceResizerSpec

Protected Member Functions

BeginPlay ()	Signature virtual void UMRUKGridSliceResizerComponent::BeginPlay() override Returns `void`
OnRegister ()	Signature virtual void UMRUKGridSliceResizerComponent::OnRegister() override Returns `void`

Member Functions

SliceMesh ()	Slice the mesh. This gets automatically called whenever the scale of the owning Actor changes. Signature void UMRUKGridSliceResizerComponent::SliceMesh() Returns `void`
TickComponent ( DeltaTime , TickType , ThisTickFunction )	Signature virtual void UMRUKGridSliceResizerComponent::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction ThisTickFunction) override Parameters `DeltaTime: float` `TickType: ELevelTick` `ThisTickFunction: FActorComponentTickFunction ` Returns `void`