Volumetric Shadows for Particles

Volumetric shadow map, slice rendering, and the light-facing pass

Volumetric Shadows for Particles centers on a render path that draws animated particle effects such as smoke, steam, and dust with volumetric shadows from a dynamic light source. A volumetric shadow map is built before the particles are drawn, then the particles are rendered from the viewpoint of the light using multiple render targets. The setup uses a modern approach to the conventional slice-based technique in order to achieve high performance, flexibility, and quality.

The render flow is direct. For 6 and 12 slices, the particles are drawn once. For 24 slices, they are drawn one additional time. The shadow map is then used to draw both the particles and the surfaces in the scene with volumetric shadows. That makes the package useful when particle motion needs to stay connected to the light rather than appearing as a flat overlay.

Slice counts and light types

The asset gives a choice between 6, 12, and 24 slices, along with two light setups: an orthographic directional light or a perspective spotlight. Those options shape how the volumetric effect is built and how the shadowing behaves around the particle volume. The same workflow can therefore be adjusted to match a lighter or more detailed shadow setup without changing the overall rendering approach.

Several demo scenes are included to show the supported combinations in action: 12SliceFire, 12SliceFireOrtho, and 24SliceSmoke on Windows, plus matching versions for Mac. The scene names reflect the slice counts and light types available in the package and give a clear view of how the effect is intended to be used in practice.

Particle looks: smoke, fire, and shaded surfaces

Volumetric shadows are only part of the visual result here. The package also supports soft particles, emissive effects like fire, custom surface shading with normal mapping, and Unity’s soft and hard shadows for shadowing surfaces. A solution is included for casting solid surface shadows on particles, which gives the effect a stronger link to the environment around it.

These pieces make the tool relevant for effects that need depth and light response at the same time. Smoke and steam can carry the shadow information, dust can sit more convincingly in a lit space, and fire can keep an emissive look while still fitting into the same shading workflow. The combination of volumetric shadows and surface shading is what gives the package its practical range.

• Soft particles
• Emissive effects like fire
• Custom surface shading with normal mapping
• Unity soft and hard shadows for surfaces
• Solid surface shadows on particles

Unity version, platform support, and update history

The package is compatible with and tested on Windows and Mac operating systems. It is compatible with Direct3D 9 and above, as well as OpenGL 2.1 and above. Shader Model 3.0 is required, and it is not recommended for most mobile devices. The original Unity version is 5.5.0, and the supported Unity versions listed are 5.5.0 and 2017.1.1.

Technical details also place the asset in the Particles & Effects category, with the category path tools/particles-effects. The package type is unitypackage. Its file size is 6.0 MB, the asset count is 118, the latest version is 1.5, and the latest release date is Oct 24, 2017. It was first published on Mar 29, 2016.

Updates carried into version 1.5

Version 1.5 updated scenes to make them more appropriate for the highest version of Unity and for smoother upgrades in the future. It also removed deprecated GUI Layer components. Earlier changes added a smoothScale with a smoothing function to reduce jittering, and a shadowClipOffset field for adjusting clipping of volumetric shadows between the light and the particle volume.

That leaves the package focused on a clear task: rendering particle effects with volumetric shadows while keeping the light setup, slice count, and surface response available for adjustment in a Unity project.

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