When importing high poly 3D models for mobile performance, prioritize retopology (reducing polygon count) and texture compression to lighten the model’s load on mobile hardware.
Retopology replaces dense high-poly geometry with an efficient, mobile-friendly mesh (e.g., quad-based topology), while texture formats like ASTC/ETC2 shrink file sizes without losing key detail—both are critical for maintaining frame rates and avoiding overheating.
For a quick start, use Blender’s Remesh tool for automatic retopology, then test the model in Unity/Unreal to tweak based on real mobile performance.