Out of GPU memory
Scene size is limited by video memory (VRAM). BLUX estimates the need before you run, and warns you.
Reading the estimate
Section titled “Reading the estimate”The Diagnostics panel shows This scene, an estimate of the GPU memory the current scene needs, compared with the free memory.
| Status | When |
|---|---|
| Safe | The estimate is below 70% of the free memory. |
| Warning | The estimate is above 70% of the free memory. |
| Critical | The estimate is above 90% of the free memory, or above 95% of the GPU’s total memory. A box appears in the main panel. |
The estimate is per solver:
| Solver | Estimate based on |
|---|---|
| Blaze | The domain geometry and the backend. |
| Hydro | The total particle count of the emitters (about 160 bytes each), plus a spatial hash of about 100 MB, plus the whitewater pool if whitewater is in the graph. |
| Atom | The particle allocation tier (250,000, 1 million or 4 million, about 330 bytes each) plus the grid. |
| Impact | A small constant, about 50 MB. |
It is an estimate. The surface mesher and other programs also use the GPU.
Lower Resolution to Fit
Section titled “Lower Resolution to Fit”When the status is Critical, the main panel shows Lower Resolution to Fit. What it does depends on the solver:
| Solver | Action |
|---|---|
| Blaze | First switches to the Sparse backend. Each further click raises the Voxel Size by 1.26 times, which halves the cells. |
| Hydro | Clamps any emitter above 100,000 particles to 80,000. |
| Atom | Sets the grid to 96³ and caps the particles at 1 million. |
| Impact | No change. |
Click again if it is still Critical. Check the result in Diagnostics.
Reducing a scene yourself
Section titled “Reducing a scene yourself”| Solver | What to change |
|---|---|
| Blaze | A larger Voxel Size. Halving it gives 8 times the cells where there is gas. A smaller domain box. A higher Activity Threshold. |
| Hydro | A larger Particle Radius, fewer emitter particles, or a smaller domain. |
| Atom | A lower Grid, a larger Particle Separation, or a lower Max Particles. |
| Impact | Fewer chunks in the fracture. |
Also close other programs that use the GPU, such as another copy of Blender, a game, or a browser with hardware acceleration.
Surface meshing and whitewater
Section titled “Surface meshing and whitewater”The GPU surface mesher uses a dense grid addressed by 8³ bricks, about 330 MB at its default 8-million-voxel allocation. A scene that needs more voxels is meshed at a coarser resolution automatically.
Whitewater has its own pool: Max Particles (2,000,000 by default) at about 72 bytes each. Lower it if memory is tight.
RAM and disk
Section titled “RAM and disk”These are separate from VRAM. See Cache and budgets.