Exploding bunker - Blender physics

Physics engine and particle effects: neither new additions to blender, but both fun to play with!

Category:

Film & Animation

Tags:

• physics
• simulation
• blender
• explosion
• bunker
• particles
• particle
• effects

[AriesT1]

When I stack some bricks in Blender, they are either exploding or they collapse when I start the Game Engine.

How did you make that the bricks stay on each other without moving?

[SgtZAxis]

From the sounds of things, your bricks have a bounding box larger than the bricks themselves, which makes the game engine think they're all overlapping so it forces them apart, resulting in an explosion.

This usually happens because you scaled the bricks in edit mode. For some reason, the bounding box does not follow the size of a brick that was scaled in edit mode. The solution is easy: before changing the shape and size of your bricks, switch to Object Mode.

[enjoiskate11]

very good!

[SgtZAxis]

Initially, the building included a plane just under the roof. Using game logic, I had it set to disappear ('End Object') on collision with the expanding sphere of the explosion. For the final render, this was moved to a different layer so it wouldn't be seen.

If you look closely at the early frames of the video, you can just about see a gap between the uppermost bricks and the roof. That's where the plane was.

[hahli1994]

I'd love to learn how to do all them physics particles stuff but I just dont get it, or my version 2.54 is just too different from the rest that I just cant understand the tutorials. do you have any suggestions to books or certain tutorials that I can refer to?

[AriesT1]

And how do you avoid that the boxes are jumping when you start the Game Engine?

When I start the engine, by ridig bodies are jumping a centimeter - and then the wall crashes.

Maybe you can send me your .blend file if oyu want so I can learn from you how to make such brick walls which do not collapse immediately.

[SgtZAxis]

The clouds procedural texture caused it to have the variation in texture to make it look more like a cloud of dust. If you do this, make sure to click the HaloTex button or your texture will do nothing. In addition to the clouds texture, I set Shaded on, so the dust would receive lighting.

Finally, there's an alpha IPO curve which I made by manually setting keyframes that simply causes it to fade out after a certain point, as seen in the video.

[SgtZAxis]

The icospheres mentioned above resulted in each particle coming out from the flat disc having several halos attached to it (the icosphere had a halo effect, you see). This made a thick shockwave that still expanded on a very narrow plane.

Oddly enough, I seem to have given the shockwave a blue colour. The reason it appears brown in the video is because of the lighting. More importantly, it had a clouds procedural texture mapped to alpha, giving it the blurred edges. A little more to be added.

[SgtZAxis]

The second particle object is a circle that has been extruded to form a very flat cylinder with the tops removed - basically a circle of outwards-pointing faces. This had about the same amount of force coming from the normal but no damping at all, so the particles keep moving and don't slow down. This made a flat, rapidly expanding shockwave of individual particles.

Parented to the shockwave component was a very low-resolution icosphere. Explain more in *another* comment. Damn Youtube :D

[SgtZAxis]

OK, there are two objects that launch particles. The first one is an icosphere, that creates the big, bright explosion itself. The particles on that one get most of their motion from the normals, with some randomness and a fairly large amount of damping. The material is an orange halo with X Alpha turned on. I don't know how X Alpha works, but it makes it bright white where there are a lot of overlapping particles.

Running out of space here, so I'll continue in a second comment.