After concluding our 3D body scan with Fuboss, we can obtain a file with a considerable size, in our example we start with a file of 36.8MB. Sometimes we need to make some type of post-processing in our mesh, like thicken some volumes that are too thin for the 3D printing process, to correct the color of some areas, to hollow the piece or simply to add a pedestal.
To work with such a big file could be problematic and to slow the entire task if we don't own a powerful computer.
In other cases may be we only need to upload our file to an externalized 3D printing service because we don't have a full color 3D printer. In such cases, this type of online services has a limit for the file size you can upload. Even if our file is under this limit, the quotation process or the use of their online tools for the analysis of the mesh, can take too long with the bigger files.
The main issue is that with a 3D scanner, even with the most economical ones, we obtain even more definition that which the color 3D printing process can achieve nowadays. We are talking about 3D selfies of 120-150mm height.
Then, we are overloading unnecessarily our computer, if what we need is to edit the mesh, or the server if we are processing an online order.
If we want to be more efficient, a way to do that is to reduce the number of vertices of our mesh, but this process could produce the loss of the color details, obtaining a blurred image.
Following I will explain a method to reduce the number of vertices of our 3D scan without losing too much detail in the color info. We will need the open source software Meshlab.
Open the ply file in Meshlab. At the bottom of the screen, we can read the number of vertices of our mesh. In this case is of 919.633 vertices.
If we make a zoom we can see how dense the mesh is.
We will try to reduce the number of vertex without losing too much geometry. First we will make a copy of the mesh. If you don't see the "Layer Dialog", go to "View/Show Layer Dialog" and select. Now you can see the Layers/Meshes.
Select the Layer 1 and with the right button select "Duplicate Current Layer". Now you can hide the first mesh by pressing in the eye icon.
If the new one appears without color, go to “Render/Color/Per Vertex”.
Now we will reduce the number of vertex of this second mesh. Go to “Filters/Remeshing, Simplification and Reconstruction/Quadratic Edge Collapse Decimation”.
The following window will appear. Enter a percentage of reduction from 0 to 1. I like to use a small reduction and press Apply as many times as desired.
In the following image you can see the reduced mesh. We have reduced the number of vertex from 919.633 to 324.423 that is a 65%.
If we compare the first mesh with the simplified one, we can see how much this process affects to the color information. The eyes appear blurred.
Now we will eliminate the color information of the simplified mesh. Go to “Filters/Color Creation and Processing/Vertex Color Filling”. The following window will appear. Select preview to see the result and press Apply. Now the color of the mesh is white.
Once we have the desired size of the mesh and the color information eliminated, we will "Project" the color information of the first one onto the second one. Go to “Filters/Sampling/Vertex Attribute Transfer”. Select as Source Mesh the first one and as Target Mesh the simplified one. Press Apply.
As you can see, with this process we don't lose so much color details as when we only apply the filter to reduce the mesh. Now export the reduced mesh as .ply and save it. We have reduced the file size from 36.8MB to only 8.31MB without a significant loss of definition.