DrawCallAnalyzer — Documentation

v1.0.0 · Blender 3.2 + · Unity (URP / HDRP / Built-in) / Unreal 4-5 / Godot 4 · Windows / macOS / Linux

1. Install

1. Download drawcall_analyzer_v1_0_0.zip (do not unpack).
2. Edit → Preferences → Add-ons → Install..., pick the ZIP, enable DrawCallAnalyzer.
3. Press N in the 3D Viewport → DrawCalls tab.

2. Quick start

1. Pick a platform: Mobile / Console / Desktop.
2. Pick scope: Scene or Selected Objects.
3. (Optional) toggle Detect LODs + pick the active LOD level.
4. Click Analyze Scene.

3. How draw calls are counted

One DC per used material_index per renderable mesh. A mesh with 5 slots but polygons using only slots 0 and 2 counts as 2 draw calls. hide_render + collection-level hide_render are respected.

This matches what Unity / Unreal / Godot actually submit. Addons that count per material_slot overestimate by 2-5×.

4. Batching candidates

• Static — meshes sharing a material with combined verts < 64,535. Skinned meshes excluded.
• Dynamic — meshes sharing a material with each < 300 verts.
• GPU instancing — objects sharing the same mesh.data collapse to one draw per unique material.

5. LOD chain detection

Auto-detects _LOD0/LOD1/LOD2 naming (case-insensitive, _ or - separator). With Detect LODs on, only the active LOD level is scored. Warnings fire for:

• Misordered LODs — higher LOD has more verts than lower.
• Weak reduction — LOD saves < 10% verts vs previous level.

6. Platform presets

7. Texture VRAM

Sums per-image size using platform-correct bits-per-pixel: Desktop (BC1/5/7, DXT, RGBA8), Mobile (ASTC, ETC2, PVRTC), Console (BC1/5/7). Per-texture breakdown sorted by size.

8. Overdraw heatmap

Counts AABB overlaps per object via a 16×16×16 spatial hash (replaces old O(n²) loop). Camera-aware when a scene camera is set. Tints viewport object color green (LOW ≤1 overlap) / yellow (MEDIUM ≤3) / red (HIGH ≥4). Use Clear Overdraw Colours to restore.

9. Report export

Export Report writes the last analysis as JSON (machine-readable) or CSV (Summary + Per-material + Instancing groups + Suggestions sections). Pin to a PR, diff between runs.

10. Snapshot & Compare

Snapshot stores current analysis on the scene. Compare shows the delta vs that snapshot. Useful for tracking optimization wins.

11. Troubleshooting

Numbers don't match Unity Frame Debugger — DCA scores 3D scene geometry only. Real-time lights, shadow passes, post-processing, UI canvases add extra DCs that DCA doesn't model. For the 3D portion, ±5% accuracy.

Overdraw all red — AABB overlap over-counts for L-shaped / hollow geometry. First-pass triage tool, not pixel-accurate.

LOD detection misses my naming — regex expects _LOD or -LOD at end of name. Spaces don't match.

Export Report: nothing to export — run Analyze Scene first.

12. Limitations

• Particle systems and hair are not analysed.
• Real-time lights, shadow passes, post-processing not modelled.
• SRP Batcher savings not auto-detected (engine-specific).
• Overdraw via AABB overlap over-counts on hollow geometry.

13. Support & License

Through marketplace messaging. GPL-3.0.