diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc744e8e448e3bff130444abb025258638ddad8e..7503f5118ff53d6a686ad832601ad26b0629f2be 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@ Note that since we don't clearly distinguish between a public and private interf
 - Make operators in `IndexPairBonds` a directed property
 - Remove erroneous bounding-box overlap test in `Structure.eachUnitPair`
 - Fix `EdgeBuilder.addNextEdge` for loop edges
+- Optimize inter unit bond compute
+- Improve SSAO for thin geometry (e.g. lines)
 
 ## [v3.35.0] - 2023-05-14
 
diff --git a/src/mol-gl/shader/ssao.frag.ts b/src/mol-gl/shader/ssao.frag.ts
index ac851e47fa8bf28a56dc78e379c5559c90c07dcb..cdc86f31437bbb0925083e55e441e473034955fc 100644
--- a/src/mol-gl/shader/ssao.frag.ts
+++ b/src/mol-gl/shader/ssao.frag.ts
@@ -114,7 +114,7 @@ void main(void) {
     vec2 selfPackedDepth = packUnitIntervalToRG(selfDepth);
 
     if (isBackground(selfDepth)) {
-        gl_FragColor = vec4(packUnitIntervalToRG(0.0), selfPackedDepth);
+        gl_FragColor = vec4(packUnitIntervalToRG(1.0), selfPackedDepth);
         return;
     }
 
diff --git a/src/mol-model/structure/structure/unit/bonds/inter-compute.ts b/src/mol-model/structure/structure/unit/bonds/inter-compute.ts
index 1a8603945776d17e39c65d4a4fde46c1a4b8c11e..7186e8efab4a2e3e2084f666a8288da3f767d19e 100644
--- a/src/mol-model/structure/structure/unit/bonds/inter-compute.ts
+++ b/src/mol-model/structure/structure/unit/bonds/inter-compute.ts
@@ -243,10 +243,8 @@ function computeInterUnitBonds(structure: Structure, props?: Partial<InterBondCo
         ...p,
         validUnit: (props && props.validUnit) || (u => Unit.isAtomic(u)),
         validUnitPair: (props && props.validUnitPair) || ((s, a, b) => {
-            // In case both units have a struct conn record, ignore other criteria
-            if (hasCommonStructConnRecord(a, b)) {
-                return Structure.validUnitPair(s, a, b);
-            }
+            const isValidPair = Structure.validUnitPair(s, a, b);
+            if (!isValidPair) return false;
 
             const mtA = a.model.atomicHierarchy.derived.residue.moleculeType;
             const mtB = b.model.atomicHierarchy.derived.residue.moleculeType;
@@ -258,7 +256,13 @@ function computeInterUnitBonds(structure: Structure, props?: Partial<InterBondCo
             const notIonA = (!Unit.isAtomic(a) || mtA[a.residueIndex[a.elements[0]]] !== MoleculeType.Ion);
             const notIonB = (!Unit.isAtomic(b) || mtB[b.residueIndex[b.elements[0]]] !== MoleculeType.Ion);
             const notIon = notIonA && notIonB;
-            return Structure.validUnitPair(s, a, b) && (notWater || !p.ignoreWater) && (notIon || !p.ignoreIon);
+
+            const check = (notWater || !p.ignoreWater) && (notIon || !p.ignoreIon);
+            if (!check) {
+                // In case both units have a struct conn record, ignore other criteria
+                return hasCommonStructConnRecord(a, b);
+            }
+            return true;
         }),
     });
 }