diff --git a/src/Measure/MeasureDistance/index.js b/src/Measure/MeasureDistance/index.js
index 7bb3749..52755af 100644
--- a/src/Measure/MeasureDistance/index.js
+++ b/src/Measure/MeasureDistance/index.js
@@ -91,7 +91,7 @@ class MeasureDistance extends Measure {
 
 
     //暂时固定取20个点
-    if (d > 20) {//大于20m时，固定取20个点
+    if (d > 2) {//大于20m时，固定取20个点
       meters = d / 20
       await start(meters)
     } else if (d < 1) {
@@ -106,8 +106,8 @@ class MeasureDistance extends Measure {
 
 
   async sampleHeight(p1, index) {
-    let p2 = await this.sampleHeightMostDetailed([p1])
-    p1.alt = p2[0].height
+    let height = await this.getClampToHeight(p1, [...this.sdk.viewer.entities.values])
+    p1.alt = height
     return {position: p1, index}
   }