Custom crash model

[Alexis]

This one should be quick:

Does anyone know if we can have a custom crash model instead of relying on the visual model for crashbox generation?

 

[arno]

Hi,

The crash model is always made up of boxes, so in that sense it's not really a model. I guess it might be possible to generate the crash boxes from a different model and then merge the results. For shadow models I've done that before.

 

[=rk=]

Granularity can go a long way to defining shape. At it's lowest level it is a single box that just covers the extremities of the model and at it's highest level appears to be a stack of bricks that exactly conforms to the model's dimensions.

 

[arno]

Yes, but if you do that the performance is gone due to the huge crash tree

Would be good to know why the OP wants the crash tree generated from a different object.

 

[=rk=]

Indeed. In my case, I was developing an aircraft carrier model and to complicate matters, it had a "ski jump" deck. I'd felt like I needed to bore a tunnel through the crash box. We have also seen this issue arise on hospital helipads and so far, the resolution has been to strike a balance between granularity and performance, such that the rotor blades can not touch the crash box during the normal course of operation.
I can't see how a substitute crash box would suffice, on this basis; we are always dealing with granularity as fidelity and the crash box is ultimately intended to define the fidelity of solid objects. So, you could compose a low granularity crash box, based on the immediate surroundings of the landing area and then add complex geometry with the understanding that the aircraft is not intended to encounter that portion of the model. This might be useful on a limited scale, for something like an oil rig model.

 

[Alexis]

I can see a solution being possible, through the use of multiple simobjects with different granularities; one for the Hull, then one for the Island etc. That opens another can of worms, though. I guess Unreal Engine beats us to it...

 

[arno]

But can you tell us what problem you try to solve with this?

 

[Alexis]

But can you tell us what problem you try to solve with this?

I forgot that. I am constructing a ship with walkable interiors for FSX and P3D. I usually compile without crash boxes to faciliate aircraft movement, in this case they are necessary as the avatar walks through the walls.

What I am thinking now is creating the carrier crash-free and merging in some strategically placed invisible walls to keep Casper from walking through the walls. Or using a separate simobject for the walkable areas.

 

[=rk=]

You could place hard platforms strategically that probably would do the trick, you might be able to set the auto function to cover every interior surface, I've done it on a very curved bridge to keep AI cars from falling through.