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How do you change a material's color on a mesh at runtime in Unreal Engine?

Recolor a single mesh at runtime without affecting other meshes that share the same base material. Create the dynamic material instance once in BeginPlay, then change its color in SetHighlightColor.

Constraints:

Use a UMaterialInstanceDynamic via CreateDynamicMaterialInstance — never edit the base asset.
Create and cache the instance once (in BeginPlay), not per frame.
Set a named vector parameter (e.g. "BaseColor") exposed by the material.

void AHighlightActor::BeginPlay()
{
    Super::BeginPlay();
    // your code here
}

void AHighlightActor::SetHighlightColor(const FLinearColor& Color)
{
    // your code here
}

Write the implementation.

Create a UMaterialInstanceDynamic with CreateDynamicMaterialInstance on the component, then call SetVectorParameterValue with a named parameter. Editing the base material asset directly would affect every mesh that uses it.

✗Editing the shared base material asset, which changes the color on every mesh using it
✗Forgetting the material must expose a named vector parameter for the call to work
✗Creating a new dynamic instance every frame instead of caching one and reusing it

→When should you create the dynamic material instance — BeginPlay or on demand?
→How does SetScalarParameterValue differ from SetVectorParameterValue?

Contents

Problem

You need to recolor a mesh during gameplay — for example, to highlight an object on hover. The base material cannot be edited directly: it is shared, and editing it would affect every mesh that uses it.

Solution

Create a UMaterialInstanceDynamic (MID) — a lightweight instance that reuses the base material's compiled shader and lets you change exposed parameters.

// In the actor header:
UPROPERTY()
UMaterialInstanceDynamic* DynMaterial = nullptr;

void AHighlightActor::BeginPlay()
{
    Super::BeginPlay();

    // Create the MID once and cache it. Index 0 is the material slot on the mesh.
    DynMaterial = MeshComponent->CreateDynamicMaterialInstance(0);
}

void AHighlightActor::SetHighlightColor(const FLinearColor& Color)
{
    if (DynMaterial)
    {
        // "BaseColor" is the vector parameter name exposed in the material graph.
        DynMaterial->SetVectorParameterValue(TEXT("BaseColor"), Color);
    }
}

Key points