diff --git a/src/mode/sla/client.js b/src/mode/sla/client.js
index 78330ed1..d58a7213 100644
--- a/src/mode/sla/client.js
+++ b/src/mode/sla/client.js
@@ -92,7 +92,9 @@
             range.min = 0;
             range.max = lines.length - 1;
             range.oninput = function() {
-                let lineDV = new DataView(lines[range.value]);
+                let pdata = lines[range.value];
+                if (!pdata) return;
+                let lineDV = new DataView(pdata);
                 for (let i=0; i<lineDV.byteLength; i++) {
                     imgDV.setUint32(i*4, lineDV.getUint8(i));
                 }
diff --git a/src/mode/sla/export.js b/src/mode/sla/export.js
index 68d166c5..b9ec9c95 100644
--- a/src/mode/sla/export.js
+++ b/src/mode/sla/export.js
@@ -107,7 +107,7 @@
                 slices.push(lines);
                 // transfer image memory to browser main
                 // it *should* be sampled to save memory
-                image = image.buffer;
+                image = image ? image.buffer : undefined;
                 online({
                     progress: (index / layermax) * part1,
                     message: "image_gen",
diff --git a/src/mode/sla/x_halot.js b/src/mode/sla/x_halot.js
index 596fa936..85da6ac7 100644
--- a/src/mode/sla/x_halot.js
+++ b/src/mode/sla/x_halot.js
@@ -341,7 +341,7 @@
             writePoly(writer, poly);
         }
         wasm.render(0, imagelen, 0);
-        let image = wasm.heap.slice(0, imagelen);
+        let image = wasm.heap;//.slice(0, imagelen);
         let lines = [];
         for (let x=0; x<width; x++) {
             let y_start = 0;
@@ -361,7 +361,8 @@
                 lastv = v;
             }
         }
-        return { image, lines };
+        return { lines };
+        // return { image, lines };
     }
 
     if (!this.navigator && this.process && this.process.env) {
diff --git a/wasm/kiri-sla.wasm b/wasm/kiri-sla.wasm
index 78f8a492..91617871 100755
Binary files a/wasm/kiri-sla.wasm and b/wasm/kiri-sla.wasm differ
diff --git a/wasm/makefile b/wasm/makefile
index 75c49510..772f4cbf 100644
--- a/wasm/makefile
+++ b/wasm/makefile
@@ -1,7 +1,7 @@
 all: kiri-sla.wasm kiri-geo.wasm kiri-ani.wasm
 
 kiri-sla.wasm: kiri-sla.c
-	emcc --no-entry -o kiri-sla.wasm kiri-sla.c -O3 -s ERROR_ON_UNDEFINED_SYMBOLS=0
+	emcc --no-entry -o kiri-sla.wasm kiri-sla.c -O3 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s TOTAL_MEMORY=40mb
 
 kiri-geo.wasm: kiri-geo.cpp
 	emcc --no-entry -o kiri-geo.wasm clipper.cpp kiri-geo.cpp -Oz -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s TOTAL_MEMORY=40mb