Why Continuous Collision Detection and Broadphase are game-Changers for INTERACT
- julienicoloff07
- Jul 1
- 4 min read
New physics simulation features: How Continuous Collision Detection and Broadphase Elevate Your Experience
Thanks to our research partner CEA, we have integrated two groundbreaking advancements into the physics engine XDE integrated into our software INTERACT and XRTwin. These new features are called: Continuous Collision Detection (CCD) and Broadphase collision detection. These enhancements make simulations more realistic, intuitive, and performant, transforming how you interact with objects in our platform. If terms like “physics engine” or “collision detection” sound technical, don’t worry, this article is designed for everyone, no science degree required! We’ll break down what these features are, why they matter, and how they’ll make your experience smoother and more immersive.
By the end, you’ll understand how these upgrades eliminate common frustrations, like objects passing through each other or the need to tweak complex settings, and deliver a seamless, realistic simulation. Let’s dive in!
What Is a Physics Engine, and Why Does It Matter in INTERACT?
Let’s start with the basics. A physics engine is like the invisible puppeteer, controlling how objects move, collide, and interact in the virtual world. Since day one, LS Group software have been about one thing: making industrial simulations feel real, whether you’re designing complex equipment, validating an ergonomic workstation, or testing maintenance scenarios in VR.
However, simulating physics in real-time is tricky. Computers process the world in tiny time steps (think of them as snapshots), and fast-moving objects or complex scenes can sometimes cause glitches, like objects passing through walls (called “tunneling”) or sluggish performance. That’s where our new features, CCD and Broadphase, come in, solving these issues to make your simulation feel more lifelike and responsive.
Part 1: The Problem – Why Physics Sometimes Fails in Simulation
Let’s imagine you are simulating a machine assembly where a parts are supposed to collide and fit together.
If those parts are moving quickly, say in a fast assembly motion, and your physics engine only checks collisions once every frame, the parts can simply "skip over" the collision between two frames. This is called tunneling, fast-moving objects pass through other objects because the collision wasn’t detected in time, and it’s frustrating because it breaks the realism of the simulation.
What do users typically do to avoid this?
🔹 Decrease time step (slow down the physics)
🔹 Increase object size artificially
🔹 Tweak parameters like solver iterations endlessly
Bottom line? You spend a lot of time adjusting physics settings just to make basic interactions feel right.
Part 2: Continuous Collision Detection (CCD) – No More Tunneling
This is where Continuous Collision Detection (CCD) comes in.
Rather than checking for collisions once per physics frame, CCD predicts where objects will move between frames and checks for possible collisions along the entire path.
Think of it like drawing an imaginary sweep path for fast-moving objects and asking:
“Is there anything this object might hit along its way?”
If there is, the physics engine catches the collision early and prevents the object from passing through. If a collision should happen, like a bullet hitting a wall, CCD catches it, even if the object moves too fast for the standard time step.
Why CCD matters in INTERACT or XRTwin
Fast-moving parts stay realistic
Moving parts, tools, or robots won’t pass through other parts unnaturally anymore.
Less need to fine-tune physics parameters
You no longer have to manually slow down your simulation or tweak collision margins to avoid tunneling.
Improved training and validation
When teaching assembly, maintenance, or manipulation tasks in VR, what you see now matches what would happen in reality, even with quick hand or tool motions.
Your benefit? Faster, more reliable simulations with less manual tweaking.
Part 3: Broadphase – Smarter Collision Detection for Better Performance
Now imagine you have a factory scene in INTERACT with hundreds of 3D parts:
Tables, tools, machines, cables, screws… everything.
If the physics engine had to check every object against every other object to see if they collide, the number of checks would be enormous (and your PC would melt).
That’s where Broadphase Collision Detection helps.
Instead of naively testing everything with everything, Broadphase acts like a smart traffic controller:
🔹 It quickly filters out objects that are far away from each other
🔹 It only performs detailed collision checks on objects that are actually close together
It does this by using spatial partitioning structures (like bounding boxes or grids). You don’t see these, but behind the scenes, it’s organizing your scene much more efficiently.
Why Broadphase matters in INTERACT or XR TWIN
Better performance in large scenes and stable simulations
If you’re working with complex CAD and multiple rigid body parts, physics stays fast and fluid by reducing the number of collision checks. As scenes get bigger, the simulation performance doesn’t drop dramatically, collisions are still detected accurately without lag.
No Need to Optimize Physics Parameters
Previously, you might have had to manually adjust settings like collision layers or simulation distances to improve performance, which could be daunting. Broadphase automates this optimization, so you get great performance out of the box.
Your benefit? You can simulate complex industrial environments smoothly, and faster.
How CCD and Broadphase Work Together
CCD and Broadphase are a dynamic duo, addressing different but complementary challenges in LS Group software. CCD ensures that fast-moving objects collide accurately, preventing tunneling and enhancing realism. Broadphase optimizes the collision detection process, making it fast and efficient even in crowded scenes. This balance of accuracy and performance is exactly what industrial VR users have been asking for, and now it’s built directly into INTERACT.
The integration of CCD and Broadphase is just the beginning. At LS Group, our goal with is simple: Remove the barriers between you and your simulation. Now you can focus on creating, training, and validating, not tweaking settings or fighting unrealistic behavior.
We’d love to hear your feedback! How are CCD and Broadphase impacting your projects? Are there specific scenarios where these features shine, or areas where you’d like further improvements? Share your thoughts in the INTERACT community forums, and let’s keep pushing the boundaries of what’s possible.
