From 837458abf27a13e10ede29226bbe3aa30c3b9791 Mon Sep 17 00:00:00 2001
From: jiaweig <jiaweig@amazon.com>
Date: Mon, 3 May 2021 20:23:03 -0700
Subject: [PATCH] ATOM-15391 [RHI][Vulkan][Android] SSAO introduces horizontal
 lines on flat surfaces

---
 .../Common/Assets/Shaders/PostProcessing/SsaoCompute.azsl       | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Gems/Atom/Feature/Common/Assets/Shaders/PostProcessing/SsaoCompute.azsl b/Gems/Atom/Feature/Common/Assets/Shaders/PostProcessing/SsaoCompute.azsl
index c1fa41991e..8294911b44 100644
--- a/Gems/Atom/Feature/Common/Assets/Shaders/PostProcessing/SsaoCompute.azsl
+++ b/Gems/Atom/Feature/Common/Assets/Shaders/PostProcessing/SsaoCompute.azsl
@@ -277,6 +277,8 @@ void MainCS(uint3 thread_id : SV_GroupThreadID, uint3 group_id : SV_GroupID, uin
 
         // Gather depth values
         float2 depthGatherUV = mad(float2(ldsPosition), GetPixelSize(), ldsOffsetUV);
+        // Gather on some GPUs will fall onto same pixels in adjacent coordinates due to rounding errors
+        depthGatherUV += GetHalfPixelSize();
         float4 depthGather = PassSrg::m_linearDepth.Gather(PassSrg::PointSampler, depthGatherUV);
 
         WriteDepthGatherToLDS(ldsPosition, depthGather);