Where it is

3D Viewport → Sidebar (N) → Decimate Pro

Quick workflow

1. Select a mesh object (Object Mode).

2. In Heat Map, pick a Preset (optional).

3. Click View Heat Map to preview (switches to Weight Paint view).

4. Adjust heat-map sliders until the preview looks right.

5. (Optional) Click Estimate Face Count.

6. In Rebuild, set Decimate Ratio and options.

7. Click Rebuild Mesh.

Tip: Rebuild Mesh changes your mesh (it applies modifiers). Use Undo or duplicate the object first if you want a backup.

Heat Map basics

• The add-on writes weights into a vertex group named DECIMATEPRO_Density_Map.

• Think of the heat map like this:

  • Higher weight = more protected = keeps more polygons

  • Lower weight = less protected = simplifies more

Heat Map controls

Preset + preview

• Preset

  • Loads a ready-made set of heat-map settings for a goal (hard surface, organic, silhouette, etc.).

  • Choosing a preset overwrites the sliders; changing any slider switches you to “Custom”.

• View Heat Map

  • Turns live preview on/off.

  • When on: updates the map as you change sliders and shows it in Weight Paint mode.

• Advanced Controls

  • Shows/hides the full set of heat-map and cleanup options (basic mode shows only the essentials).

Core heat-map sliders

• Base Weight

  • Raises or lowers the starting density everywhere.

  • Higher = overall more protected (less reduction overall).

• Curvature Influence

  • Adds density on edges, corners, and high curvature areas.

  • Higher = sharper features keep more polygons.

• Curvature Power

  • Shapes how strongly curvature “kicks in”.

  • Higher = focuses protection more on the sharpest features; lower = spreads it more gently.

• Detail Influence

  • Adds density where local faces are already small (areas that look “detailed”).

  • Higher = preserves fine surface detail more aggressively.

• Z-Height Influence

  • Adds density toward the top of the mesh (based on local Z).

  • Higher = top keeps more polygons.

• Slope Influence

  • Adds density on steeper surfaces (based on the surface normal).

  • Higher = steeper areas keep more polygons.

• Radial Influence

  • Adds density farther from the mesh center.

  • Higher = preserves silhouette/outside regions more.

• Contrast

  • Expands or compresses differences in the heat map.

  • Higher = more extreme “protected vs simplified” zones; lower = more even distribution.

• Bias

  • Shifts the entire map up or down.

  • Positive = more protection everywhere; negative = less protection everywhere.

• Invert Weights

  • Flips the map.

  • Use when the result looks “backwards” (protected areas become simplified, and vice versa).

Smoothing

• Smooth Iterations

  • How many smoothing passes to run.

  • More iterations = broader, softer transitions between dense/sparse areas.

• Smooth Strength

  • How strongly each smoothing pass blends with neighbors.

  • Higher = smoother gradients; lower = keeps sharper changes in density.

Very low density (extra reduction)

• Allow Very Low Density

  • Allows the map to go into very low weights in sparse zones.

  • Useful for extreme reduction, but can increase collapse/artifacts in thin areas.

• Low Density Floor

  • The minimum weight allowed when “Allow Very Low Density” is on.

  • Lower floor = more aggressive simplification in low-priority zones.

Performance controls (Advanced → Heat Map → Performance)

• Large Mesh Safeguards

  • Prevents heavy live preview work on very dense meshes.

• Live Preview Vertex Limit

  • Live heat-map preview pauses if the mesh vertex count is above this value (when safeguards are enabled).

• Estimate Vertex Limit

  • A threshold intended for estimation safeguards.

  • Note: in this build, estimation does not meaningfully change behavior based on this value.

• Processing Chunk Size

  • Controls how much work is done per update during Rebuild Mesh.

  • Higher = faster rebuild but more UI hitching; lower = smoother UI but slower rebuild.

• Tick Time Budget (ms)

  • Caps how long each rebuild “tick” can run.

  • Higher = faster rebuild but can make Blender less responsive; lower = more responsive UI.

Rebuild controls

Main rebuild target

• Decimate Ratio

  • The overall reduction target.

  • Lower = fewer polygons; higher = closer to the original.

  • The heat map redistributes this so important areas lose less detail.

Feature protection (helps preserve key structure)

• Protect Borders

  • Preserves open boundaries (holes, open edges) more.

• Border Boost

  • Strength of border protection.

• Protect UV Seams

  • Preserves geometry along UV seams more.

• Seam Boost

  • Strength of seam protection.

• Protect Sharp Edges

  • Preserves sharp edge regions more.

• Sharp Boost

  • Strength of sharp-edge protection.

• Sharp Angle

  • Face-angle threshold for what counts as “sharp”.

  • Lower angle = more edges treated as sharp; higher angle = fewer edges treated as sharp.

Shading cleanup (optional)

• Add Weighted Normals

  • Adds a Weighted Normal modifier after rebuild to make shading look cleaner (especially on hard-surface meshes).

• Weighted Normal Weight

  • Strength of the weighted normal effect.

  • Higher = stronger “flat/clean” shading influence.

• Keep Sharp

  • Keeps sharp edges respected when computing weighted normals.

• Face Influence

  • Uses face influence data (if present) to guide the weighted normals result.

Topology cleanup (optional)

• Resolve Self Intersections

  • Attempts to fix geometry where the mesh intersects itself (can be heavy and can alter topology).

• Intersection Threshold

  • Precision/tolerance for the intersection cleanup.

  • Smaller = more precise; larger = more tolerant.

• Remove Interior Faces

  • Deletes faces detected inside the mesh shell (common scan cleanup step).

• Remove Spikes

  • Removes “spike-like” artifacts by dissolving spike vertices.

• Spike Cone Angle

  • Controls how aggressively spikes are detected.

  • Higher angle = more aggressive spike removal.

• Recalculate Normals

  • Rebuilds normals to point consistently outward after cleanup.

• Tri to Quad Cleanup

  • Converts suitable triangles into quads after cleanup (when possible).

• Quad Face Angle

  • Controls how similar adjacent face angles must be to convert tris to quads.

  • Lower = stricter (fewer conversions); higher = more conversions.

• Quad Shape Angle

  • Controls shape tolerance for tri-to-quad conversion.

  • Lower = stricter; higher = more permissive.

Mirror output (optional)

• Mirror Output

  • Mirrors the rebuilt result around the mesh’s geometric center in local space.

• Mirror X / Mirror Y / Mirror Z

  • Chooses which local axes to mirror across.

  • Use for symmetrical objects; make sure the symmetry plane runs through the mesh center.

Running and cancelling

• Rebuild Mesh

  • Runs heat-map generation + decimation + cleanup (with progress).

• Cancel Rebuild / ESC

  • Stops a running rebuild job.

Face Count Estimate

• Estimate Face Count

  • Predicts the approximate face count after rebuild without changing the mesh.

  • Best used after you’ve set your heat map and Decimate Ratio.

That’s everything you need: preview the heat map, tune the sliders, estimate, then rebuild.