Using Wind material node (Not simple grass wind)?

So I’m adding a wind effect to some ground foliage in my level. I started by using the SimpleGrassWind node but this doesn’t allow you to control the wind based on the WindDirectionalSource actor in your level so I thought I’d try the Wind node instead. The documentation says that support for referencing a wind actor isn’t fully implemented yet. Has this been fixed? How do you reference an actor from a material?

https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/Functions/Reference/WorldPositionOffset/index.html#wind

Hey TorQueMod,

After testing the ‘Wind’ node material function within my test bed project and attempting to get it to work as intended, I went ahead and entered a bug report. So in order to use the ‘Wind’ node correctly, you need to reference the wind directional source within your level by creating a Vector4 Parameter and calling this through blueprints. This is currently un-achievable since the node will not accept the parameter as an input for the function.

Wind Material Function

41475-windvector4.png

41474-windvector4parameter.png

Currently this function seems to be still in development. I do not currently have a time when this will be completed, but you can use the ‘SimpleGrassWind’ node and modify its output so you can have a bit more control over the parameters within the function. If you have any other questions or need additional assistance please let me know.

Cheers,

Andrew Hurley

Thank you Andrew for the info.

I’ve managed to append a Constant float to the Vector parameter and feed it to the Wind node. No errors any more.

57266-снимок.png

I am not sure what that wind node does, but it may be best to append the actual alpha of the vector instead of 0. It might be using the alpha as a strength value or something.

On multi pin nodes like that, the top white pin always just does V3, you need to append the alpha if you want to use the full V4.

I always assumed that the wind node was meant to tie the grass and foliage (and any other material) effects to the wind actor in your scene. What’s the point of the wind actor if you can’t use it to adjust the power and speed of the wind through the level blueprint? As of the current build, there’s seemingly no way to adjust the strength of the wind that’s applied to procedural grass for example.

Hey TorQueMoD,

There is a known issue with updating the Wind Source Actor via Blueprints (UE-3309). I have provided a workaround to another user reporting this issue in 4.7.6 and gave him a few screenshots.

The most important part about this set up is updating the Wind Directional Source rotation because for some reason, this also updates the values you might be adding to Strength or Speed.

Wind Dynamic Update

I am also working on a tutorial to show users how to control the Wind Directional Source actor through UMG, soon! I will post this on my Wiki profile page with my other tutorials.

Cheers,

Andrew Hurley