Rain - Water Drop - Flow Material & FX System

This material set is used for rain flow effect on surfaces like glass windows or solid surfaces. Scene is included.

Pack has 4 types of usage:

1. Translucent Material

2. Material Overlay Function (needs Blueprint editing on an existing material)

3. Material Overlay Volume (projection decal system that doesn't require any editing, just copy & paste)

4. Camera Post Process Effect

Forward Shading Incompatibilities:

• Rain overlay volume system in the rain material pack uses "scene texture: world normals" which is not supported on projects with "forward shading". So it won't be possible to use rain volume BP on VR projects. but animated translucent rain material, post proces volume, and rain overlay material are usable on projects that uses "forward shading".

Unreal Engine 5 Incompatibilities:

• Crashes on the projects if (experimentalI) Substrate Materials are enabled.
• Material Overlay Volume system causes ignoring smooth normals because of a bug stated here.

Update 5! (May 2024)

Fixed particle emitter spawn area for better collision calculation.

Fixed raindrop lifetime calculation for exact boundary for the particles.

With this update Rain Overlay Volume Blueprint has additional parameters.

Raindrop Lifetime - Particle lifetime for the drops

Runtime Enable - Enable this for having the rain BP system on simulation or gameplay. Enabling this paramteter will disable the BP system in the editor to prevent duplication.

Technical Details

Warning: Because of a bug stated here, material overlay volume doesnt work right on 4.22 and 4.23. That bug fixed on 4.24.2.

General flow speed: Set 0 to stop all flowing.

Mask general flow speed: If general flow speed is not 0, this will set the general speed of vertical flow piles.

Bottom layer flow speed: Set 0 to stop 1/3 of drops.

Bottom mask flow speed: This will set the partial speed of vertical flow piles on bottom layer. Set it 0 to hide 1/3 of vertical flows.

Middle layer flow speed: Set 0 to stop 1/3 of drops.

Middle mask flow speed: This will set the partial speed of vertical flow piles on middle layer. Set it 0 to hide 1/3 of vertical flows.

Top layer flow speed: Set 0 to stop 1/3 of drops.

Top mask flow speed: This will set the partial speed of vertical flow piles on top layer. Set it 0 to hide 1/3 of vertical flows.

IOR: Index of refraction value

Opacity-control: Material opacity value

Specular amount: Material specular value

Static speed: This value will set the flow speed of tiny drops between static drops.

Static drop on?: Set it to 1 for horizontal surfaces that has no flow. (General flow speed must also set to 0)

Static drop speed: This is the refresh rate of changing positions of the drops which looks like rain fall on surface.

UV multiplier: Tile multiplier of the general Material.