RTS Fog

Unity Engine
1

Hello,
Im working on an RTS and im trying to figure out how i cam make the entire map black except for the areas that the player has been. Also i want the black to fade away as the player moves.

thanks

2

You could have a mesh placed in between the camera and the top of your troops and then remove and re-add triangles to it depending on the position of the troops.

If you want fog of war to re-appear you could have two such meshes - one with a completely black texture and one with a semi-transparent one.

3

file:///Applications/Unity/Documentation/ScriptReference/Mesh-triangles.html

4

There is a “fade between camera and player” script floating around here. It was written to keep things from obstructing the camera’s view of the player by fading them out while they were in the way.

I would build a prefab of a single “area” shape like a black box (if you use squares to make a grid). Apply this script to it, but change the script mentioned above in three ways:

  1. Disable the part that fades it back to opaque again
  2. make it fade the cube all the way out
  3. Turn off/Disable/Destroy/Unload the cube when it has faded all the way out

that’s what I would do.

I’ll see if I can find it…

5

Thanks all!
yes I would like that script if you could find it.

6

Hi Drag0nsphere,
I think I’ve got this script… :slight_smile:

/* Fades out any objects between the player and this transform.
   The renderers shader is first changed to be an Alpha/Diffuse, then alpha is faded out to fadedOutAlpha.
   Only objects 
   
   In order to catch all occluders, 5 rays are casted. occlusionRadius is the distance between them.
*/
var layerMask : LayerMask = 2;
var target : Transform;
var fadeSpeed = 1.0;
var occlusionRadius = .3;
var fadedOutAlpha = 0.3;

private var fadedOutObjects = Array ();

class FadeoutLOSInfo
{
	var renderer : Renderer;
	var originalMaterials : Material[];
	var alphaMaterials : Material[];
	var needFadeOut = true;
}

function FindLosInfo (r : Renderer) : FadeoutLOSInfo
{
	for (var fade : FadeoutLOSInfo in fadedOutObjects)
	{
		if (r == fade.renderer)
			return fade;
	}
	return null;
}

function LateUpdate () {
	var from = transform.position;
	var to = target.position;
	var castDistance = Vector3.Distance(to, from);
	
	// Mark all objects as not needing fade out
	for (var fade : FadeoutLOSInfo in fadedOutObjects)
	{
		fade.needFadeOut = false;
	}
	
	var offsets = [Vector3(0, 0, 0), Vector3(0, occlusionRadius, 0), Vector3(0, -occlusionRadius, 0), Vector3(occlusionRadius, 0, 0), Vector3(-occlusionRadius, 0, 0)];
	
	// We cast 5 rays to really make sure even occluders that are partly occluding the player are faded out
	for (var offset in offsets)
	{
		var relativeOffset = transform.TransformDirection(offset);
		// Find all blocking objects which we want to hide
		var hits : RaycastHit[] = Physics.RaycastAll(from + relativeOffset, to - from, castDistance, layerMask.value);
		for (var hit : RaycastHit in hits)
		{
			// Make sure we have a renderer
			var hitRenderer : Renderer = hit.collider.renderer;		
			if (hitRenderer == null || !hitRenderer.enabled)
				continue;
			
			var info = FindLosInfo(hitRenderer);
	
			// We are not fading this renderer already, so insert into faded objects map
			if (info == null)
			{
				info = new FadeoutLOSInfo ();
				info.originalMaterials = hitRenderer.sharedMaterials;
				info.alphaMaterials = new Material[info.originalMaterials.length];
				info.renderer = hitRenderer;
				for (var i=0;i<info.originalMaterials.length;i++)
				{
					var newMaterial = new Material (Shader.Find("Alpha/Diffuse"));
					newMaterial.mainTexture = info.originalMaterials[i].mainTexture;	
					newMaterial.color = info.originalMaterials[i].color;
					newMaterial.color.a = 1.0;
					info.alphaMaterials[i] = newMaterial;
				}
				
				hitRenderer.sharedMaterials = info.alphaMaterials;
				fadedOutObjects.Add(info);
			}
			// Just mark the renderer as needing fade out
			else
			{
				info.needFadeOut = true;
			}
		}
	}
		
	// Now go over all renderers and do the actual fading!
	var fadeDelta = fadeSpeed * Time.deltaTime;
	for (i=0;i<fadedOutObjects.Count;i++)
	{
		var fade = fadedOutObjects[i];
		// Fade out up to minimum alpha value
		if (fade.needFadeOut)
		{
			for (var alphaMaterial : Material in fade.alphaMaterials)
			{
				var alpha = alphaMaterial.color.a;
				alpha -= fadeDelta;
				alpha = Mathf.Max(alpha, fadedOutAlpha);
				alphaMaterial.color.a = alpha;
			}
		}
		// Fade back in
		else
		{
			var totallyFadedIn = 0;
			for (var alphaMaterial : Material in fade.alphaMaterials)
			{
				alpha = alphaMaterial.color.a;
				alpha += fadeDelta;
				alpha = Mathf.Min(alpha, 1.0);
				alphaMaterial.color.a = alpha;
				if (alpha >= 0.99)
					totallyFadedIn++;
			}
			
			// All alpha materials are faded back to 100%
			// Thus we can switch back to the original materials
			if (totallyFadedIn == fade.alphaMaterials.length)
			{
				if (fade.renderer)
					fade.renderer.sharedMaterials = fade.originalMaterials;
					
				for (var newMaterial in fade.alphaMaterials)
					Destroy(newMaterial);
				
				fadedOutObjects.RemoveAt(i);
				i--;
			}
		}
	}
}

@script AddComponentMenu ("Third Person Camera/Fadeout Line of Sight")
7

that’s the one.

thanks Gaston!