SPH - Maxwell Render

RealFlow does not only provide a convenient method to create plain previews from the viewports, but also to render photorealistic images and movies with Maxwell Render's FIRE engine. With FIRE you can evaluate the look and feel of your current scene together with materials and a physically correct lighting system in realtime. This absolutely unique feature is not only available with particle-based fluids, but throughout all node groups – even Hybrido and RealWave are supported. To make use of this high-quality preview system, each node provides a “Maxwell Render” panel where you can find specific settings for the render process. RealFlow also provides a wide range of predefined materials for watery substances, solid objects, ocean surfaces and many more. The concept of one-panel-per-node has another huge advantage: it is possible to render interacting with different properties, for example oil and water or milk and honey.

When we say “realtime”, we definitely mean realtime, because the “Maxwell Interaction” window (this is the place where you can see the current preview) directly reacts on any change of view you make in the viewport and updates the image accordingly, but also on parameter changes. Additionally, it is possible to create a complete preview sequence of your simulation and assemble the frames to a complete movie. This way you do not have to import the simulation data to your 3D application anymore, set up a complete environment and adjust lighting. Now, everything can be done directly within RealFlow and you can even control the quality of the render with just a few clicks.

To activate the Maxwell Render preview option, simply follow a few easy steps:

File (OS X: RealFlow) > Preferences > Preview > Renderer > Maxwell Render

Layout > Maxwell Interactive

If you are not happy with the current lighting setup or render speed you can either change this globally under “Preferences” again

File (OS X: RealFlow) > Preferences > Preview > Renderer > Maxwell Options

or you make settings for each scene individually with the “Maxwell Scene Preferences” from the “Icon Bar”. Please also visit the “Maxwell Options” chapter [ here ] for detailed information about the parameters.

Renderable

Each emitter can be excluded from the render with this switch. With “Yes” (the default setting) the node will be visible in the preview. Please note that the node's viewport visibility is not taken into consideration by default, and the “Yes” and “No” states work independently from the “Set Selected Visible” and “Set Selected Hidden” options. If you want to use the current state of visibility in the viewport for the node, choose “Same as display”.

Material

As mentioned in the introduction, RealFlow already provides many common materials, for instant usage, but there is more: with “From Node”, Maxwell will take the colour from the “Node” panel's “Color” parameter. There you can specify any colour by simply using the operating system's colour picker. Please bear in mind that colours are always rendered opaque (non-transparent).

“From File” gives you the possibility to load a Maxwell material file directly from your hard drive. If you already use Maxwell Render in your production environment, you can create your own material definitions with the “Mxed” application – the Maxwell material editor. You can also find a lot of ready-to-use materials in your Maxwell application folder. Another method is to freely register on Maxwell's online material database and download files:

http://resources.maxwellrender.com/

The “From File” option also unlocks the “@ File” field where you can browse your disk to search for a material file. Maxwell materials have the extension MXM. The last option is to choose from one of the listed materials which come with RealFlow. When you have a closer look at the drop-down menu you will notice that we have also included some light emitters. These materials can be applied to an object to light your scene.

@ File

This field is only available when “Material” is set to “From File”. A click into the empty field opens a file picker and you can load any valid MXM file.

Multipoint

If you want to render a fluid as a particle cloud then this is your option. With “Multipoint”, RealFlow adds new particles to create a denser and more realistic look. Especially with foam or spray, “Multipoint” helps to achieve a realistic impression. The value determines the number of extra particles that will be created per existing particle. An example: let's say you have a low-resolution fluid simulation with 50,000 particles and the preview looks a little poor. Now you enter a value of 7 and RealFlow will add 7 x 50,000 new particles to the render. Since this process is procedural, it is very fast.

By default, all these new particles are added at exactly the same position as the source particles and therefore they might not be visible. To change this, we have introduced the “Dispersion” parameter. Multipoint particles are not written to disk or the BIN file(s) and your simulation will not be changed. The particles are only visible in the rendered image.

Dispersion

By default, Multipoint particles are added at the same position as their source particles. With this parameter you can define a radius around a particle where the new particles are created. When the radius that is chosen is too big, it is very likely that the new particles interpenetrate solid objects in the render. To mention it again: Multipoint particles are only created at render time and then discarded. This value is given in metres [m].

Radius

Particles are rendered as spheres and here you can determine their radius. The default value is 0.006.