Preview and performance

Open Painter's GPU engine keeps the material connected while you paint, adjust masks and rearrange layers. For detailed assets and large stacks, use preview resolution, layer caches and profiling to keep editing comfortable.

The Open Painter Engine

The engine renders layers, masks and procedural sources into the texture set's channel images. An edit updates the affected channels from the changed layer upward and reuses unchanged results. Numeric edits such as opacity, scale and seed update without compiling a new GPU program.

Blender reads the result through one Open Painter Texture Set node connected to the Principled BSDF. The same set can feed another material: add the node from Shader Editor › Add › Input and choose your texture set. Its Normal output combines the normal map and height bump.

Find expensive layers

Choose Performance › Profile Layers. The report shows each layer's GPU time, CPU input work and CPU reference evaluation, together with its Live, Cached, Frozen, Stale, Pending or Bypassed state. Cost badges help you find layers worth caching; select one to see its breakdown in the Inspector.

The reference resolution (256, 512 or 1024) controls the CPU profiling pass. GPU timings use the texture set's current resolution. Clear Profile resets the collected counters.

Profile Engine and Copy Engine Report

Performance › Profile Engine measures individual GPU passes, including each Mask Graph, and copies a report to the clipboard. It lists the heaviest work by layer, channel and mask, along with the time spent building, updating, rendering and publishing the result.

Use Copy Engine Report to copy the latest report without running another profile. Include it when reporting a slow preview so the report contains your Blender, graphics and timing details.

Bypass in Preview

Use the toggle beside a layer's visibility control, or Performance › Bypass Selected, to temporarily skip its preview work. A bypassed folder also skips its children. This is useful while painting under a detailed finishing pass.

Restore Selected and Restore All bring the layers back. Export and full composite snapshots still include them. Use the ordinary visibility control when you want a layer hidden in the final result too.

Cache a finished part of the stack

Cache a paint layer, fill layer or isolated folder from its Performance section. For example, cache a finished base material while painting decals and scratches above it. Opacity, visibility and blending stay live, and an isolated folder keeps its own mask live too.

A passthrough folder blends with the layers below it. Cache its children individually, or switch it to Isolated to cache the folder as a unit. Cached images save with the project; use Refresh Cache after changing resolution. Cache the layers that profiling identifies as expensive, since each cached channel adds image memory.

Freeze While Painting

This option is enabled by default in the Performance menu. Native brush strokes update their canvas while expensive filters, caches and scene analysis wait until you release the stroke. The status line shows when those effects are catching up. Paint Material also gives live feedback as you paint across enabled PBR channels.

Preview resolution and status

Texture Set Settings › Preview Quality offers Full, 512 and 1024 previews. Use a lower resolution for broad color and wear decisions, then switch to Full for fine detail. Export uses the authored resolution.

The Texture Set panel and header show Idle, Updating, Stale, Baking, Failed or Paused. If a frozen layer looks out of date, refresh its cache. Performance Inventory lists project resources. See troubleshooting for other preview fixes.