# I did change polydata of actor but suddenly show old model when I interact after change

**URL:** <https://discourse.vtk.org/t/i-did-change-polydata-of-actor-but-suddenly-show-old-model-when-i-interact-after-change/5851>\
**Category:** Development\
**Created:** [May 24, 2021, 5:49am UTC](https://discourse.vtk.org/t/i-did-change-polydata-of-actor-but-suddenly-show-old-model-when-i-interact-after-change/5851 "2021-05-24T05:49:11Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![ChiShouWu](https://discourse.vtk.org/user_avatar/discourse.vtk.org/chishouwu/32/3446_2.png) [@ChiShouWu](https://discourse.vtk.org/u/ChiShouWu)\
**Post date:** [May 24, 2021, 5:49am UTC](https://discourse.vtk.org/t/i-did-change-polydata-of-actor-but-suddenly-show-old-model-when-i-interact-after-change/5851/1 "2021-05-24T05:49:11Z")

</div>

I did change polydata of actor like this

```
mapper->setInputData(newPolydata);
actor->setMapper(mapper);
renderer->render();

```

But when I interact with my actor after change, it show as image below.  
How to fix it?  
 ![ezgif-1-826e11a35d84](https://discourse.vtk.org/uploads/default/original/2X/a/ae0c0b157f42af290953544d76926ba7bbae6cfd.gif)