How to fix badly meshed water in Blender (sea, rivers, lakes etc.)

Water does not mesh well. It is reflective and moves around a lot. In this article we are going to show you how to fix your badly meshed and textured water.

We made a scan of a garden pool, and this is how the water meshed:

We will be making the water in Blender, so the first thing to do is to simplify your model down to a manageable size for import to blender. This is just for reference so it does not need to look good or be textured. I simplified down to 10,000 triangles:

Then export the model model as an .obj, making sure to include the .rcinfo file as this will preserve the scale and orientation when we re-import the model we will make in blender:

Now it's time to import the model in Blender. Go to File > Import > Obj and make sure to set z as up:

Then model in blender roughly what you would imagine is containing the water, in this case it is the inside of the pool, but it could be a river bed or the seafloor, depending on what you are trying to create. If you are new to modeling in blender, you can find a lot of tutorials online for modelling for beginners:

Then make sure you have selected only your new sculpted model, and export it, over-writing the original model made in RC (same name), this way the .rcinfo file will be used on import as it has the same name. Also again make sure to set z as up, and check the box that says "selection only":

Now you can import your model into RealityCapture, and then unwrap it and texture it:

We have a nice clean mesh of the inside of the pool. Select the badly meshed water using the lasso tool, and then filter the selection:

Next export both this model (simplified to a manageable size) and the new model of the inside of the pool, and import both models into blender.

The only thing left to do is to create the water surface. We made this simple cylinder, but for the sea, lake or a river , a flat plane is fine. 

Then you can make a simple shader for the water, this is the one we made, with some noise going into the displacement to make some ripples. (There is also an hdri for the reflections in the water):

Here is a before and after: