PML - Mesh

The "Mesh" panel allows you to adjust the polygon structure of your fluid mesh. You can also choose from different types of mesh creation, and you will find optimization tools when defining a camera-based level of detail. These functions directly influence file size and the amount of detail of the final mesh.

Build

By switching from "Yes" to "No" you can prevent the mesh engine from creating meshes during the simulation. It is highly recommended to perform meshing as a post process to have full control over the settings. Additionally it is often necessary to create sample meshes from different frames to achieve a consistent look.

Type

You can choose from three types: “Metaballs”, “Mpolygons”, and “Clone obj”. “Metaballs“activates the standard meshing engine to create the familiar fluid look. “Metaballs” creates spheres around the particles. These spheres influence each other based on the related "Field" settings.

“Mpolygons” works similar to “Clone obj”, but does not give you the possibility to define a custom object. RealFlow automatically attaches a 2D polygon to each particle to represent the fluid cloud. “Clone obj” unlocks the subsequent parameter field and lets you choose any available node. Each particle is then represented by the selected particle. The result looks like an instanced object, though it is not really instanced, but cloned. This means that you will need much more disk and RAM resources than with instances. The more complex the clone object, the bigger the final file.

Clone obj

This is the place to choose the node you want to use for the “Clone obj” type. It is only possible to select a single object – multi-selection is not supported.

Polygon size

This is the most important setting when considering structure and surface, because it strongly influences the final size. Smaller values create higher resolutions and more polygons. With higher resolutions you can generate a better-fitting mesh with more details. A mesh can be compared to a wireframe that is spread over an object. Now imagine a wireframe with just a few cells: It is very hard to sculpt the grid and wrap it tightly around the underlying object. The denser the grid cells, the more accurate the results will be, and that is exactly the effect with smaller “Polygon size” values: The mesh fits better to the outlines of the particle cloud, showing more details.

Please keep in mind that rounded or thick fluid borders cannot be removed with more polygons. If you want to create a mesh with thinner edges, use a “@ Tension” filter, change your "Field" settings, add more particles and consider scene scale.

@ Num Faces

This value cannot be changed directly. It depends on “Polygon size” and will be updated automatically when any mesh parameters have changed, and the mesh was built again. While building the entire mesh range, “Polygon size” will also display the number of faces with each frame. By using small “Polygon size” settings and large meshes, “@ Num Faces” can easily reach several hundreds of thousands or a few million polygons.

LOD resolution

With this option it is possible to adjust a view-dependent mesh resolution based on your camera settings and point of view. It is not only possible to define a distance range, but also the minimum and maximum size of the polygons. This feature allows you to customize your mesh to always achieve the best quality. The further away the polygons, the lower the resolution that can be adjusted. By activating “LOD resolution”, the associated settings are unlocked.

@ LOD Camera

Of course, “LOD resolution” needs a camera object to work. You can choose any available camera node from a list. The field of view and point of view settings are analysed and used for the calculation of the mesh’s resolution.

@ Min distance

This is the minimum distance from the camera and represents the area with the highest resolution. It interacts with “@ Max distance” and the range between both values is interpolated, building a range. Within this range, RealFlow calculates the appropriate polygon resolution. "@ Min distance" is measured in metres [m].

@ Min Polygon size

The minimum size of the high resolution area is determined here. If your camera is very close to the mesh, the “@ Min Polygon” size should be correspondingly smaller.

@ Max distance

The maximum distance from the camera is specified with this value. "@ Max distance" is measured in metres [m].

@ Max Polygon size

If the distant areas of the mesh are very far away from the camera, this value can be rather big. Make sure you avoid a coarse look of the final mesh.