How can I reduce visual snow

Let there be snow - Polysnow for 3ds Max

This article originally appeared in the DP 02: 2019.

The Polysnow plug-in for 3ds Max was published by the user batuha nozer52 on the CGTrader - - platform at the end of 2018 and can be easily found using the search function. After purchase, the tool is installed in 3ds Max using drag and drop. If there are already permanent plug-in folders connected to 3ds Max in the system, the script file can be stored there.

For the sake of simplicity, the tool window is called up using a keyboard shortcut that has to be assigned in advance. The user can expect an intuitive user interface with a manageable number of setting options. There is no danger of getting lost in the complexity. The function of the little helper is based on the detection of underlying objects and the application of snow cover. A snow cover consists of a multitude of particles that are used to define a volume that is covered with geometry.

The first blanket of snow

In order for users to be able to create a snow cover, a geometry must be selected. As soon as a selection has been made, the "Create Snow Preview" button must be pressed in the Polysnow window. The object is immediately covered with a blanket of snow. A loading bar was placed above the button as visual feedback. After the construction has been carried out successfully, a window appears with a note about the process sequence - it would be commendable by the developer to design the window or its appearance as optional. In terms of structure, the geometry resembles the type of snow that is predestined to build snow families or to create trails for cross-country skiing.

Users can determine the resolution of the geometry. The responsible global parameter increases or decreases the value listed below for the particle size - which can be adjusted manually, regardless of the global multiplier.

Usually, the two values ​​are enough to create blankets of snow that agencies can use to render numerous Christmas cards. If you want more detail, you can look further down in the window. In the Snow Paint area, a button can be used to selectively apply additional snow to existing snow. A small new layer of snow can either be applied to the existing snow cover by pressing the "Create Snow Preview" button again or using the "Snow Paint" function. Additional particles are applied to existing particles depending on factors such as particle size.

The snow job, however, looks less like an order, regardless of which method was used, but rather like overlapping geometry. The “Merge Snow” function in the “Extras before Bake” field provides a remedy. The name of the function gives another property of the tool price. They are particles with attributes that are used to enclose the geometry. Users are allowed to adjust the appearance according to the available setting options. If you are satisfied, the snow cover can be baked. A state is created which creates a polygonal object from the modular object. In short: all Polysnow functions are created as modifiers of the respective object on the basis of a blob mesh. By pressing the Baking, all levels are merged into one and converted into an editable mesh.

Live adjustments

If users have any wishes regarding the appearance of the snowpack, there is the option of checking the "Live Parameters" field before baking. This contains four adjusting screws for the representation of the snowpack. The first parameter is the Mesh Resolution - the resolution of the geometry. The smaller the value, the greater the number of polygons. It is gratifying that the topology works with quads. This facilitates the later application of further modifiers. The particle size expands or rather thickens the snow surface. The tension, the surface tension, ranges between zero and one. The full surface tension creates a fresh blanket of snow as one is used to from fresh snow. The lower the surface tension, the looser the snow appears - filled with moisture. The fourth option for making settings is via the relax parameter. The more relaxed the geometry should be, the larger the value, the softer the surface of the snowpack appears. In conjunction with the particle size and resolution, the effect of wet snow can be enhanced.

The adjustable values ​​are rounded off by a handful of buttons. The five buttons are in another compartment called “Extras before Bake”. The first way to give the snow more realism is to add more detail using the "Add Surface Detail" function. Here, two further modifiers are introduced, the result of which is similar to a 3D noise, but with two different grain sizes. However, users quickly get detail that improves the visual impression of snow.

The second function is called "Move Snow Up". The selected snow object is moved upwards a bit. A function that is useful when working with thin layers of snow. The third function called “Edit Particles” is self-explanatory. The basis of the system are the particles. Users are given the opportunity to edit the particles. They can be moved or deleted in the event that the snow cover occurs in places where snow in the respective version is unthinkable and / or possible.

The fourth function, “Merge Snow”, is exciting - there are snow cover and snow details in the most varied of designs. Created by users, any number of layers of snow can be placed on objects. either numerous layers of snow or by using the paint-snow function. The Merge Snow function comes into play so that all individual snow objects are now welded into one and overlapping geometry dissolves, similar to a Boolean operation on two bodies.

If there are too many snow objects (particle objects) in larger scenes, which may not make sense for a structure, then users can use the "Scene Cleanup" function to clean up automatically. Then nothing stands in the way of the baking process and a static object for further steps or the final rendering can also be prepared at the push of a button.

The final look

The snow has been prepared and users have to take care of the final appearance themselves. We are talking about the material or the creation and assignment of materials. With the large selection of renderers and material descriptions, it is obvious that this does not necessarily have to be incorporated into the Polysnow system.

For 19 US dollars there is a fast and solid-working tool for creating snow cover that does not raise any big questions and does what it should. It is also compatible with the latest version of 3ds Max. Material creation can be just as easy. Since 3ds Max natively supports Substance Archive and Allegorithmic offers a free plug-in for Max, it makes sense to take a look at the Substance Share and Substance Source portals to get hold of snow material for free or to buy one for little money, that was created by experienced users.

Rainer Duda is a lecturer at Furtwangen University in the field of computer science with a focus on computer graphics and managing director of rd | innovations.