Since transparent surfaces do not have any depth, it’s not possible to sort them on a per-pixel basis. This is the case for any transparent shader, not just the water.

Instead, transparent material are sorted based on their position, render queue value and layer order to determine which material should draw over the other. For more information see the Unity manual page (also applies to perspective camera setups).

To remedy this:

• Set the “Order in layer” value on the Sprite/Particle System (found in the Rendering section) to a value higher than 0. This way it’ll always draw over the water
• (Or) On the particle material, increase the “Priority” value by one
• (Or) Set the render queue on the water material to 2999 (found under the “Advanced” tab). It’ll render behind everything else.
• Fallback: Enable the “Alpha clipping” option on the transparent material

Alternatively, turn on the “ZWrite” option on the water material, found under the “Advanced” tab.

ZWrite ON: Transparent materials will properly intersect with the water, parts can be above and below the water. As long as they’re on the same render queue.
ZWrite OFF: Transparent materials are sorted based on their position, order in layer and the material’s render queue (labeled “Priority” on URP’s particle shader). They will either render behind or in front of the water.

The refraction features make use of the Opaque Texture URP renders. As the name implies, this texture represents the screen’s image right after opaque geometry is drawn but before transparent materials are rendered (including water).

Because of this, transparent materials aren’t captured in this texture, thus can’t be refracted.

It’s likely, when the game is running on the device, a different Quality profile is used than in the editor.

If you have different pipeline assets assigned, per quality level, ensure the “Depth Texture” option is also enabled for them.

See the Getting Started page for more details.

The effect relies on the depth texture Unity renders, which provides a means to measure the distance from the water surface to an object’s pixel on screen.

As such, shaders that don’t support depth writing will not be affected. This usually means:

• Transparent materials (water/particles/etc)
• Unlit materials (before Unity 2021.1)
• Sprites
• UI elements
• Details/grass rendered through the terrain system
• Custom (handwritten) shaders without a DepthOnly pass
• Anything rendered through a custom render loop, without a depth buffer (if you’re developing this, you probably already know this)

On the water material, you’ll notice an error that indicates that the “Depth texture” option is disabled in your URP settings. Click the “Enable” button next to it to enable this. After which, the water will render correctly.

Ensure Dynamic Clipping is enabled:

Alternatively, disabled it and bump up the “Near” value to ~0.5

In the scene view bar, check if the “Always Refresh” option is enabled. In Unity 2019 this was called “Animated Materials“.

If not, any kind of shader animation only update when the scene view is refreshed (eg. selecting something or moving the camera).

The color gradient and intersection effects are both based on the depth texture Unity renders. On mobile platforms, this depth texture is of lower precision, so it’s possible any depth-based effect pans out a little differently.

To increase the accuracy of the depth texture:

• Ensure the camera’s far clipping plane (set on the Camera component) is as small as possible.
  • For orthographic camera’s move the camera as close as possible.
• Increase the near plane value. If no objects come near the camera, you can get away with this.

The intersection foam effect is based on the depth texture Unity renders. On mobile platforms, this depth texture is of lower precision than on PC/Consoles. This means in the far distance, the depth value (of any given pixel) may be very close to that of the geometry behind it (eg. 0.98553 vs 0.98554). Due to floating point rounding errors, these values may move back and forth, which translates to a visual artefact.

Solutions:

• Limit the maximum render range by decreasing the camera’s far clipping plane value (set on the Camera component).
• Draw the foam effect through Vertex Colors so that its based on static data.

This issue is caused by transparency sorting, mobile devices are less accurate in this manner, especially with orthographic cameras.

To rectify this:

• Reduce the “Far clipping plane” on your camera until it starts to clip your geometry. By default this is set to 1000 units, which is overkill for orthographic scenes.
• Increasing the “Near” value.
• Move the camera as close to the environment as possible.

These steps reduce the rendering range for the camera and therefore increase the accuracy of sorting. After which, the water should render correctly.

This is entirely attributed to the result of texture compression.

You can disable compression on the normal map that is being used on the material to resolve this, at the cost of more memory (~4x).

Objects rendered after transparent materials, such as through the Render Objects render feature or Overlay cameras will show these artifacts.

This is because these objects will render after the water has been. As such, when the water shader renders it’ll have no knowledge of these objects, and can’t filter them out.

This scene uses a 16k terrain, where the scene camera is 20.000 units away. At this point you’re inevitably running into floating point precision issues. On water pixels with the skybox directly behind it, depth values are reaching infinity and causes artifacts to show.

In any normal situation, this won’t occur. Otherwise, ensure there is some geometry behind/underneath the water.