# Two overlapping vtkPolyData render flashes

**URL:** https://discourse.vtk.org/t/two-overlapping-vtkpolydata-render-flashes/5136
**Category:** Support
**Created:** [February 4, 2021, 8:59am UTC](https://discourse.vtk.org/t/two-overlapping-vtkpolydata-render-flashes/5136 "2021-02-04T08:59:30Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Lisa](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/l/f08c70/32.png) [@Lisa](https://discourse.vtk.org/u/Lisa)
#### Post date: [February 4, 2021, 8:59am UTC](https://discourse.vtk.org/t/two-overlapping-vtkpolydata-render-flashes/5136/1 "2021-02-04T08:59:30Z")

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Hi everybody,  
I would like to render two overlapping vtkPolyData using two different color(white and yellow) maps in the same renderer. i want to show yellow vtkPolyData. but, The result is as shown in the figure. what should i do. ![result](https://discourse.vtk.org/uploads/default/original/2X/6/6fa3561b673ccbeaa65c80acb3389d25653b76ac.png)

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### Author: ![lassoan](https://discourse.vtk.org/user_avatar/discourse.vtk.org/lassoan/32/50_2.png) [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [February 5, 2021, 2:45pm UTC](https://discourse.vtk.org/t/two-overlapping-vtkpolydata-render-flashes/5136/2 "2021-02-05T14:45:36Z")

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Search for “coincident topology” in the VTK documentation to find methods to force one mesh appear in front of the other when they are very close.