One thing I can proudly proclaim is I can really destroy things in 3D. Not just tear them up… destroy them. In fact, I was fortunate enough to spend a few years of my freelance career in creating destructible props and scenes in 3DS Max and later in iClone.
I’ve fractured, exploded, imploded, splintered, spindled, and mutilated many a mesh under the guise of gainful employment.
Some of you are thinking… hell… I can do that. I can tear stuff up. I can destroy things. There are many pitfalls between destroying things and believably simulating a disaster or act of war.
With iClone physics and some help from Blender, we can recreate some visual special effects with somewhat believable results. For this, we will simulate a vehicle crashing through a wall. An easy enough effect for beginners while showing the basics.
One of my most popular destructible props in the Reallusion Marketplace is just such a wall. It has some drawbacks though. That prop was made years ago, in the early days before iClone had internal physics. Therefore, the animation is baked in from 3DS Max with no way to re-simulate.
In this example, we will fracture the wall prop in Blender and then use iClone physics to simulate the wall impact and outward thrust of debris. I am not a regular Blender user so there may be better ways to achieve some things than I show you as I’m taking what I do in 3DS Max to Blender as best I can.
TIP 1: TEXTURE your wall in Blender first. I didn’t for this How-To as I wanted the fragments to show up better. Once in iClone, they are 200 separate pieces requiring texturing… so do it in Blender first!
TIP 2: If you are working with a texture you can barely see then try using the TOON shader to temporarily highlight the edges of the fragments.
TIP 3: When working in iClone 7 physics go from Realtime to By Frame AND turn your visual setting down to minimal if your computer struggles with simulations.
To start with I reshaped the cube to a wall-type mesh then used the annotation pen to draw where I wanted the impact to be. Be sure to select SURFACE instead of 3D Cursor at the top of the workspace to get the pen to draw on the mesh surface. This drawing shows Blender were to fracture the wall mesh.
The inner blue circles are the impact area and outer blue lines define the limits for the fragments we will be using in iClone 7. There are many ways you can draw this so experimentation is encouraged.
If you have never used Cell Fracture then you need to go to preference in Blender and enable it. Search for Cell Fracture under Add-ons. Check the box to enable it. Once you’ve done that press F3 then type in frac to filter down to Cell Fracture. Click on the Cell Fracture entry which brings up the Cell Fracture popup shown on the left side of the image below.
Select Annotation Pencil, Source Limit: 200, Recursion: 1 and name your fragment collection (group).
With the wall selected and the appropriate setting entered you can press OK which will now fracture the wall whatever number of fragment specified by the input panel.
Go to annotations and delete the note to remove the lines we drew.
Next, delete the cube as we only want the fragments.
We want to export all the fragments (fragments only) as an FBX file for use in iClone.
Drag and drop this FBX file we just created into the iClone 7 workspace. Answer YES to the popup message telling you how many meshes are included and asking if you would like to break them up into sub props. Very important you answer yes here.
Another important step is to select ALL of the fractured props and DETACH them from the main prop which in this case was Wall1… the file name I saved it under. This is a container that can be deleted as it is not visible and no longer needed.
Select only the fragments in the area of the impact. This does not have to be precise but instead of burdening the iClone engine with Frozen objects you simply do not activate physics on those objects. Only activate fragments directly impacted by the simulation. What objects you end up activating is up to you and again, experimentation is encouraged.
Set these fragments to FROZEN.
Next set up your impact object. This can be a simple box with Kinetic physics enable or you can you a 3D object like a car. In this case, I’m using a Jeep from the early days of iClone. While this Jeep had point and click MOVE animation built-in I didn’t use it. Set a keyframe at the beginning position and ending position of the impact object’s line of travel. The number of frames between can vary with a short distance between keyframes speeding things up and a longer distance between keyframes slowing the impact down. I only used 30 frames between keyframes.
Press the run button, tweak things you don’t like and that’s it. You can use this method on columns, buildings, all sorts of shapes, and lots of 3D objects but remember… you try to fracture a mesh that already has a lot of pieces you might bring your machine to a halt. Try to keep your objects, including your impact object to minimal polycounts when possible.
There are lots of options in iClone physics that you will want to get familiar with by just trying them out and noting what they affect. Things like Mass and Drag. Anyway, this should get you started on being able to bring at least some rudimentary destruction to your animations.
M.D. McCallum, aka WarLord, is an international award-winning commercial graphics artist, 3D animator, published author, project director, and webmaster with a freelance career that spans over 20 years. Now retired, M.D. is currently working part-time on writing and select character development projects. You can learn more about MD on his website.