How to refill holes after create triangle mesh?

I’ve created the mesh but remains holes. How can I fix that?

On the Cloud interface there is no editing tool at the moment to improve the 3D Textured Mesh. However, it is possible to download the data to the Desktop version of the software by clicking Download dataset > Export to Pix4D Desktop.

There it is possible to fill holes on planar surfaces by adding surfaces (planar constraints) on a group of points in the point cloud. Here is an example: 

The steps to achieve that are described in this article from our Knowledge Base: https://support.pix4d.com/hc/en-us/articles/211083803

Some holes can also be due to lack of coverage in the original images, it is difficult to tell without more information about the project (e.g. a screenshot, Quality Report,…). In certain cases, acquiring the images once more with a higher overlap in areas that had holes can improve the reconstruction.