Normal Behavior and Expected Limits
This page gathers behaviors that can look surprising at first, but are normal for Volume Forge.
From Faces constraints are normal
The From Faces tools only work in Object Mode, with exactly two selected mesh objects, and exactly one selected quad face on each. This is not an arbitrary limitation. It is the normal input expected by the feature.
The second selected object defines side B
On From Faces creation, the first selected object defines side A (the source side), and the second selected object defines side B (the target side). In Blender, that second selected object is typically also the active object.
If the result looks reversed, check the order in which the objects were selected. A common setup is: source object first (for example a window), target object second (for example the floor).
Possible adjustment of face B
If the two selected faces do not match well, the generated prism can be adjusted on the B side. This is expected and helps keep the generated geometry planar and clean instead of producing twisted faces.
Volume Forge is not a smoke simulation system
Even in Real Fog mode, Volume Forge is still a localized volume tool driven by geometry and shader logic. It does not replace full smoke or fluid simulation.
Real Fog is not emissive
Unlike the Light mode, Real Fog does not emit light by itself. It becomes visible when the scene lighting reveals it, so an unlit or poorly lit setup can make the fog look much weaker than expected.
The final result depends on the render context
The look depends on the render engine, scene lighting, global volumetric settings, object scale, material values, and machine performance.
Edge Softness is uniform
In the current interface, edge softening is applied uniformly. It is not a per-face isolation tool.