Animating Dripping Liquid with LightWave 3D Hypervoxels

A LightWave 3D Tutorial – Animating Dripping Liquid with LightWave 3D Hypervoxels from a 3D Product Animation Project for Freelette

This is a simple technique for animating dripping liquid with LightWave 3D hypervoxels. This is only one of many different ways to animate liquid drips, but it is a quick and easy method that can be used to animate drips of a wide variety of liquids from water to honey. This method uses a set of animated null objects with LightWave 3D’s hypervoxels applied to them.

LightWave 3D’s surface hypervoxels work well to create such drips because multiple overlapping hypervoxel nulls blend together to form a smoothly flowing solid shape. In this example we’ll use a set of four nulls. Two to form the liquid pooling at the bottom of the object that’s dripping, in this case a simple sphere, and two to form the actual drip itself. By using two nulls for each it’s easy to control the elongation of the drip and the dripper. By adjusting the animation speed and motion of these nulls you can simulate a wide variety of liquids from simple water to more viscous liquids like honey, oil, goo, extracts, etc.

Step-by-step Tutorial of Animating Dripping Liquid with LightWave 3D

The following is a quick-start tutorial to show you how to animate a simple dripping liquid in LightWave 3D using surface hypervoxels and a few nulls. Once you get the hang of it you can use this simple technique anytime you need to animate dripping liquids in your own scenes. While you could work with just two nulls, one for the dripper and one for the drip, using four nulls allows you to more easily control the elongation of the liquid as the drip forms and then separates as it falls away. These settings should get you started, then feel free to experiment by changing the settings to suit your particular needs.

NOTE: I’m using the Studio Production Style menus preset in LightWave 3D 11.6.3 in the following steps. If you are using a different version of LightWave 3D or a different menu preset/layout your menu selections may be slightly different.

In a new scene set the camera to position: X 0, Y 450 mm, Z -500mm and set view to camera view.
Create a simple sphere to use as the object that the liquid is dripping from.
- Modeler Tools -> Create -> Geometry -> Sphere
- Set radius to 50 mm, Center Y to 495 mm, Sides 48, Segments 24, Activate Save Object
- Open Surface Editor and activate smoothing for the sphere object.
Create the null objects.
- Items -> Items -> Load/Add -> Objects -> Null…
- Set its position to X 0, Y 500 mm, Z 0
- Items -> Clone -> Clone Current Item
- Set Number of clones 3 (OK)
- Open Scene / Dope Editor
- Right click -> Manipulate -> Rename each of the nulls in the Scene Editor as follows: Dripper Null, Dripper Tip Null, Drip Null, Drip Tip Null
- Then Parent the tip nulls to their main nulls by dragging each under their main nulls
Set up the Hypervoxels
- More Windows -> Hypervoxels
- Select all the nulls and activate each in the Hypervoxels window.
- Set each Object Type to Surface, turn off Align to Path
- Set the following settings for the corresponding null.
  - Dripper Null: Particle Size 40 mm, Stretch Direction Y 75%
  - Dripper Tip Null: Particle Size 15 mm, Stretch Direction Y 300%
  - Drip Null: Particle Size 30 mm, Stretch Direction Y 125%
  - Drip Tip Null: Particle Size 10 mm, Stretch Direction Y 300%
- Select Dripper Null’s Blending Group -> New Group
- Default name is fine: “Blend Group(1)” (OK)
- Set each of the nulls to Blending Mode Additive and Blend Group (1)
Add another light as a fill light to the right side @50% intensity to better see the scene
Set the viewport to Camera View, VPR and activate the viewport OpenGL Preview so that we can see the hypervoxels in the viewport. Use the camera view rather than any of the orthagonal views to avoid a potential issue (see below)
Set the following animation keyframes in the Scene / Dope Editor for the nulls
- Frame 0: Drip Null Y 512 mm, Drip Tip Null Y 20 mm, Dripper Tip Null Y 30 mm
- Frame 14: Drip Null Y 473.5 mm
- Frame 18: Drip Tip Null Y 21.6 mm, Dripper Tip Null Y -20 mm
- Frame 24: Drip Null Y 327.65 mm, Drip Tip Null Y 6.35 mm, Dripper Tip Null Y 30 mm
To simulate a viscous liquid drip, we need the liquid to gather and pool with the drip slowly building and pulling down, then pausing slightly before breaking free and falling away. We need to adjust the animation motion graphs, so select the Drip Null, Drip Tip Null and Dripper Tip Null in the scene editor and then open the graph editor to load their motion curves.
Click the Channels… popup and filter channels by: *Position.Y (OK) to isolate the three Y motion channels of the nulls.
Set the following Tension-Continuity-Bias keyframe values in the Graph Editor, leaving unspecified values at 0 and Pre/Post Behaviors to Repeat
- Drip Null.Position.Y: Frame 0 – Tension -1, Frame 14 – Tension 0.8, Frame 24 – Continuity -0.335 Bias 1
- Drip Tip Null.Position.Y: Frame 0 – Tension 1, Frame 18 – Tension-Continuity-Bias all -1, Frame 24 Tension 1
- Dripper Tip Null.Position.Y: Frame 0 – Tension 1, Frame 18 – Tension-Continuity-Bias all -1, Frame 24 Tension 1

That should give you a good start. From this starting point you may further tweak the motion curves and keyframes as well as apply surfaces to suit your own needs and objectives.

Viewing Hypervoxels In-scene in LightWave 3D with VPR View

LightWave 3D VPR Camera View - Animating Dripping Liquid with LightWave 3D Hypervoxels

LightWave 3D VPR Perspective View - Animating Dripping Liquid with LightWave 3D Hypervoxels

LightWave 3D VPR Orthographic View - Animating Dripping Liquid with LightWave 3D Hypervoxels

When working with hypervoxels in LightWave 3D you can see them in the scene viewport by using the VPR view. If you enable the OpenGL Overlay in the VPR viewport you’ll also see the null objects that the hypervoxels are attached to. Be sure to use the perspective view or a camera view with VPR to avoid an issue in LightWave 3D. If you view the orthographic views (front, back, top, bottom, right, left) in VPR it may draw the hypervoxels in the wrong location and they may appear offset from the null objects that they are actually attached to. This issue has been reported (LW 11.6.3 – LW 2015) and should be fixed in a future upgrade of LightWave 3D. Until it’s fixed the simple work around is to use the perspective or camera views in VPR instead of the orthographic views. This viewport offset only affects the viewports. The hypervoxels will render in the proper locations.

Animated Drip used in Full 3D Product Animation Commercial

This animated drip tutorial is a small peek behind the scenes at the production of a 3D product animation commercial we created for Freelette as seen below.