[SOLVED!] Blob Shadows Flickering on iPhone

I've been trying to get blob shadows working on iPhone, using the shader, material and textures from the iPhone Standard Assets. They work fine in the editor, but on the device the shadows flicker. If I have only one active projector in the scene, they flicker only when moving, but with more projectors they flicker constantly.

Any ideas what could be causing this? I've been trying both normal and orthogonal projecting, tampered with the shader code and tried out different settings but to no avail.

 

Mmmmm it's not really a similar problem but I found I had a lot of framerate issues using the blob projectors and it was causing a large amount of drawcalls

In the end I just made a plane with shadow texture on it and found it just ran a lot better

 

I'm having the exact same problem. I tried all the tips from this post: http://forum.unity3d.com/viewtopic.php?t=17132&highlight=blobshadow
but nothing seems to work for me.

I filed a bugreport about a week ago, but I haven't heard from UT yet. Maybe you should file a bugreport too, so they could see that this is a quite common problem.

 

We used a plane with a blob texture set to multiply, and moved it a bit higher above the ground, and it works just fine.

 

Looks like it's Z-fighting. I think the only way to affect the Z bias is through a custom shader. Maybe you can bin up the drop shadows and render them last or raise the offset level if a custom shader is not an option.

 

I'm having the same z-fighting problem in my game on iPhone. I've followed all of the suggestions on all of the threads but nothing has fixed it. bug?

 

I refuse to use the blob shadow stuff because it performs horribly and adds a bagillion vertices. Instead, use a plane with your own shadow it in and assign a shader to it using an appropriately ordered transparent queue.

But if you have uneven terrain, then this simpler solution is useless too.

 

Yeah I have uneven terrain. So I'm still looking for a solution to the blob shadow / projector issue.

 

I found the solution. Add the following line under Pass {} in the ProjectorMultiply.shader:

Code (csharp):

1. Offset -1, -1

Here's the complete shader with the line added.

Code (csharp):

1. Shader "Projector/Multiply" {
2.    Properties {
3.       _ShadowTex ("Cookie", 2D) = "gray" { TexGen ObjectLinear }
4.       _FalloffTex ("FallOff", 2D) = "white" { TexGen ObjectLinear   }
5.    }
6.  
7.    Subshader {
8.       Tags { "RenderType"="Transparent-1" }
9.       Pass {
10.          ZWrite Off
11.          Offset -1, -1
12.          //Fog { Color (1, 1, 1) }
13.          AlphaTest Greater 0
14.          ColorMask RGB
15.          Blend DstColor Zero
16.          SetTexture [_ShadowTex] {
17.             combine texture, ONE - texture
18.             Matrix [_Projector]
19.          }
20.          SetTexture [_FalloffTex] {
21.             constantColor (1,1,1,0)
22.             combine previous lerp (texture) constant
23.             Matrix [_ProjectorClip]
24.          }
25.       }
26.    }
27. }

Offset is described in the Culling Depth Testing doc: "For example Offset 0, -1 pulls the polygon closer to the camera ignoring the polygon's slope, whereas Offset -1, -1 will pull the polygon even closer when looking at a grazing angle."

 

Hey, that worked for me too!

Thanks!

Now, I just hope they're not way too heavy for pre-3GS models..

 

Im trying to generate shadow using projector for iphone but im not able to make it can anyone guide me out there by providing some tips on how to get it done.

 

No work.... :cry:

Offset -1, -1

:evil: :evil: :evil: :evil: :evil:

It fly~~~

 

Thank you meanstreak!

That worked for me too

When I get a little more time, I will take a deeper look on what your correction means

 

@meanstreak

Code (csharp):

1. Offset -1, -1

Worked for me!

Thanks,

 

Works GREAT for me.
Does unity team confirm it is same than :

Bias = m * D3DRS_ZSLOPESCALE + D3DRS_ZBIAS
where, m is the max depth slope of triangle ******m = max(abs(∂z / ∂x), abs(∂z / ∂y))
?

 

Thank you for this feedback.

Works like a charm on PC and MacOSX .. but ... not on iPad.

Does somebody have an hint ?

If implemented using "glPolygonOffset" it seems (googling) the PowerVR SGX does not support this renderstate on iPad...

http://www.imgtec.com/forum/forum_posts.asp?TID=954&PID=3366

Can someone from Unity tell me if "glDepthRange" (workaround) is available via a "pass" renderstate ?

I have placed a "Offset -1, -1" in every "pass" section of the "diffuse" shader.
Using a 24 bits depth buffer does not solve the issue.

I am quite stuck here....

Any comment/help is welcome...

 

Here I am in 2020, and this post with "Offset -1, -1", just fixed my bug. Thank you, people of the past.