Particles are emissive in darkness

Hi all. I am currently having a sandstorm in my game using 2 of the standard asset Particlesystem prefabs "DustStorm". It looks great at "daytime" but when I rotate the light to night, the dust is emissive or sort of lit up.

I have searched the web and nothing seem to work. I have changed Shaders and fiddle with all the different sliders and numbers, no luck.

I have added a plane and a box under the terrain to add shadows that someone said but no luck.

Is there anyone here that know how to fix this? Do I have to make the Dust Storm in another way?

I have just started with Unity so NOOB warning here

 

I ended up with a colorchange on the startcolor of the "DustStorm" Particle system. It works and I will keep it untill I find another way.

 

Possibly it is using an unlit shader, which means it won't respect your lighting. You'd have to use a lit shader for that. (It takes extra processing for a shader to interpret where light is and isn't.)

 

It's not just possibly using an unlit shader, unlit particle shaders are all Unity ships with. And for dynamic shadow receiving on transparent objects it's actually impossible without making changes to the rendering systems.

The short version is along the lines of what hopeful mentioned, you need custom particle shaders that into account lighting, but these are going to make your particles significantly more expensive to render so be prepared for that. That said it's not too hard to have particles that at least respect ambient and directional lighting, if not shadows.

With Unity 5.4 you can use light probe volumes for scenes with baked lighting to get something pretty close to something that looks like it's respecting shadows, but that doesn't help you for dynamic lighting.

Unity has shown off shadows and lighting working on particles, like in the Adam short, but that's using custom shadows that haven't been released publicly.

So your options are write some shaders yourself, I posted a basic normal mapped particle shader someplace on the forum that's a good starting point for that.

Or you can get this asset which offers more control over how particles are lit, but still doesn't support shadow recieving:
https://www.assetstore.unity3d.com/en/#!/content/60561

Or you can get this asset which doesn't have quite as much control for particle lighting, but does support shadow casting on particles (via custom shadow map rendering):
https://www.assetstore.unity3d.com/en/#!/content/67665

 

I will try to build my own shaders at a later point I think.
Right now I am a total noob with Unity and somewhat new to C#, so I will stick to easy fixes so I dont get bored and quit

I dont think I need the dust to cast shadow or recive shadow, only change the color according to the time of day in a realistic fashion. The volume of the "sand" is still the same and should be.

 

The "easy" C# only solution is just change the color of the particle system dynamically.

https://docs.unity3d.com/ScriptReference/ParticleSystem-startColor.html

Make a script that changes that color based on the time of day. You could use a Gradient in your script and use something like:

myParticleSystem.startColor = dustTimeOfDayColorGradient.Evaluate(timeOfDayPercentage);

 

There may be some changes for the default particle shaders coming in Unity 5.5. Till then, another path to lit particles might also include this inexpensive particle shader pack:

Particle Shaders Vol. 1

https://www.assetstore.unity3d.com/en/#!/content/35069

 

Yes, I have made a small array with the colors that I want the dust to be and then checks the suns location on the sky with "transform.eulerAngles". I then use:
GameObject.Find("DustStorm").GetComponent<ParticleSystem>().startColor = GradienDustColors[#];
# is the color that I want when the sun is on current degree on the sky.

 

Those looks to be what I am looking for. I will look into that. Thanks

 

Sorry to resurrect this old(ish) thread, I would like to ask if you could give some sample code how to get the sky colour and assign to a particle start color, I'm just going through a similar issue and have no idea how to fix/approach this. Thanks for any help you could give.

 

https://forum.unity3d.com/threads/_worldspacelightpos0-how-it-works.435673/

 

Hi there, many thanks for the information, I'll read through that but is this worldspacelightpos something to control on the particle shader? Just making sure.

 

You create a skybox with your desired gradient or just set the color to the ambient light. The shader in #12 reply receives ambient light and directional light.