Opacity Material

• Create new material.
• Set “Blend Mode” to “Translucent”
• Set “Lighting Mode” to “Surface TranslucencyVolume”

• Base color texture
  • rgb -> Base color
  • Alpha -> Opacity
• OcclusionRoughnessMetallic texture
  • r -> Ambient Occlusion
  • g -> Roughness
  • b -> Metallic
• Normal texture
  • rgb -> Normal

https://forums.unrealengine.com/t/how-do-i-fix-this-transparency-problem/441545