diff --git a/packages/ludic.render3d/scatter.ludic b/packages/ludic.render3d/scatter.ludic
index 773a1b91..1a3aefdc 100644
--- a/packages/ludic.render3d/scatter.ludic
+++ b/packages/ludic.render3d/scatter.ludic
@@ -387,9 +387,9 @@ function layer_new(render3d_st: mut Render3dState, model: Model, cap: int, folia
   l.near = near
   l.cull = cull
   l.tint = v3_new(1.0, 1.0, 1.0)
-  # room for what the layer holds, not for what it might: 45 layers at full capacity up front were
-  # 0.4 GB, most of it never filled (plan 23 of maroon-lake)
-  l.have = min(cap, 256)
+  # the whole capacity up front: a game writes l.inst directly (Maroon Lake's prints, trees and
+  # rocks do), so a layer cannot start smaller than it may be written to
+  l.have = cap
   l.inst = floats(l.have * INST_FLOATS)
   l.scratch = floats(l.have * INST_FLOATS)
   l.last_cam = v3_new(100000.0, 0.0, 0.0)
@@ -402,7 +402,9 @@ function layer_new(render3d_st: mut Render3dState, model: Model, cap: int, folia
   return l
 }
 
-# room for n instances (at most the layer's cap), doubling what there is so a fill costs a few copies
+# room for n instances (at most the layer's cap), doubling what there is so a fill costs a few copies;
+# a caller writing l.inst itself reserves first
+function layer_reserve(l: Layer, n: int) -> void { layer_room(l, n) }
 function layer_room(l: Layer, n: int) -> void {
   if n <= l.have { return }
   var want = max(l.have * 2, n)