diff --git a/flow-state/src/scenes/shader/circuit-bloom.js b/flow-state/src/scenes/shader/circuit-bloom.js
index 6202f0c..ba3d910 100644
--- a/flow-state/src/scenes/shader/circuit-bloom.js
+++ b/flow-state/src/scenes/shader/circuit-bloom.js
@@ -32,7 +32,9 @@ export const circuitBloom = {
         // Range stops at 1.6 on purpose: the frame's far corner is about 1.4
         // units out, so anything past that is a board that already covers
         // everything, and axis travel spent up there changes nothing.
-        grown:    { type: 'float', range: [0.25, 1.6], default: 1.0,  uniform: 'u_grown', slowAxis: true },
+        // Floor raised from 0.25: below about half, the growth front has not
+        // reached far enough for any pad to be drawn and the frame is empty.
+        grown:    { type: 'float', range: [0.55, 1.6], default: 1.0,  uniform: 'u_grown', slowAxis: true },
         edge:     { type: 'float', range: [0.2, 1],    default: 0.5,  uniform: 'u_edge' },
         palette:  { type: 'palette', count: 5 },
     },
diff --git a/flow-state/src/scenes/shader/spectrum-sculpture.js b/flow-state/src/scenes/shader/spectrum-sculpture.js
index 0d93a16..c6dd6b1 100644
--- a/flow-state/src/scenes/shader/spectrum-sculpture.js
+++ b/flow-state/src/scenes/shader/spectrum-sculpture.js
@@ -17,7 +17,10 @@ export const spectrumSculpture = {
 
     params: {
         bars:      { type: 'float', range: [8, 96],   default: 40,  uniform: 'u_bars', bias: 'density' },
-        radius:    { type: 'float', range: [0.15, 0.7], default: 0.35, uniform: 'u_radius' },
+        // Floor raised from 0.15, where the sculpture was too small to register
+        // as anything and the range sweep called the frame dead. A range the
+        // generator may sample must not contain a value that renders nothing.
+        radius:    { type: 'float', range: [0.28, 0.7], default: 0.35, uniform: 'u_radius' },
         length:    { type: 'float', range: [0.05, 0.6], default: 0.25, uniform: 'u_length', bias: 'energy' },
         thickness: { type: 'float', range: [0.1, 0.9], default: 0.45, uniform: 'u_thickness' },
         // Bar segments per second, NOT turns per second. Rotating by a full turn