Traces

Understanding Line Traces

• Line Traces are fundamental blueprint tools

• Created through blueprint class actor demonstration

• Components Setup

• Static Mesh Component

  • Cone shape added
  • Line trace shoots from tip

• Scene Component

  • Empty space/void for positioning
  • Records location, rotation, scale
  • Used as proxy for line trace alignment
  • Faces x-axis by default

• Line Trace By Channel Core Parameters

• Start Point

  • Uses Scene component world location

• End Point

  • Requires Forward Vector (normalized direction)
  • Multiply by length (float conversion needed)
  • Final = Start position + offset

• Trace Channel

  • Controls what objects can be hit

• Visual Debug Indicators

• Red Line

  • Shows active trace path
  • Red square indicates blocking hit

• Green Line

  • Appears after blocking hit
  • No more information returned past this point
  • Only returns first object hit

• Collision Interactions

• Based on object collision settings

  • Physics settings > Collision presets
  • Visibility/camera trace responses

• Common Issue

  • Characters don’t block visibility channels by default
  • Must be configured for character detection

Line traces are essential tools for detecting collisions and interactions in the game world. They work by projecting a line from a start point to detect objects, with their behavior controlled by collision channel settings and object properties.