MTM2.com

Do the top-crush models only work when struck from the top, and not the side? (corrected text)

I'm working on a "paper-hoop" where the paper appears ripped after the first truck passes through it, but I'm getting no animation from impact....is this because I'm not hitting the top of the model?


Also, I think I may not be able to pass through at all.....this may be a dead-end project.

Top crush are special animated models that can be tricky to set up the way they were intended, let alone special applications. Using traxx to insert top crush wasn't well known until I did this page.

http://cownap.com/~mtmg/traxx/topcrush.html

Basically, that's all we have. I haven't tried side crush.

The page you refer to is the one I read for my experiment.....I believe I followed the instructions correctly....

The HOOP serves as the unchanged model, and there are 2 "paper" bins, one intact and one ripped, installed in an animated BIN. I installed it as instructed, but when the truck jumps in the air and strikes the center of the model, nothing happens.

I may have to try rotating the model horizontally to get top-crush to work, I don't know...I'll let you know of any progress.

Legwon's chair will have the same problems if top-contact is required.

After re-reading the page, a couple things stand out. First, the non-crush model will always be collidable (ie, not drive through). However, there is no size requirement (that I know) on the non-crush model, so it is theoretically possible to minimize it to very small (or flat) and move it out of the way. And/or. Second, there is nothing to suggest a crush model cannot be made of more than two parts. This may or may not apply here. But either way, you can (or should be able to) use the offsets to move the crushable part away from the non-crush part (I managed several unusual configurations when exploring back then). If that worked, you could use a standard model set to no collide as the facade of the main non-crush part. It's a bit of dancing around but in theory it might work. As for the top part of top crush, I think it's the force more than the direction - you can half crush models. The only draw back to crush models is that once they're crushed, they stay that way.

Well, I had some success, using your advice on using a separate model as the no-crush portion.

Apparently, the no-crush outer hoop was made solid, so nothing could pass therough it (and I could not reach the "crushable" portion. I modified the original no-crush hoop to be just a small portion of the bottom of the hoop, enough to satisfy TRAXX.

I then applied another object using the full hoop model, and setting it to no collide. That works.

HOWEVER:

I guess the routine works similar to animated bins....the computer calculates the amount the vertices are displaced upon impact, then draws the new shape.....it will always fall somewhere between the shape of the 2 animatd BIN models.

As a result, the first impact of my truck only tears the paper" partially, with the truck deflecting back or down.

On the second collision, the paper opens fully, but the truck still bounces back.....

Only now can the truck leap through the hoop......as a result of this, I don't think it would be suitable as a track item. A truck would have to be able to pass through the hoop on the first strike....oh well....

Here's a copy of the track with animated 'crush" hoop:
http://mtm2.com/~bigdogge/download/test ... h_hoop.ZIP



I have a new track idea, but it would take a lot of work (think "solving a puzzle" and "Mystery House")

> I had some success

I'll say. Good work

> I guess the routine works similar to animated bins....the computer calculates the amount the vertices are displaced upon impact, then draws the new shape.....it will always fall somewhere between the shape of the 2 animatd BIN models.

Yes, and why only two models are required. The amount of force needed is hard coded and roughly corresponds to the weight a monster truck will have on a car from the top down. (Interestingly, I got stuck on the second pass and was actually hung up on the hoop, lol).

> ...as a result of this, I don't think it would be suitable as a track item.

Ah ha, but I beg to differ. It may not be not suitable for what you had in mind, but it's perfectly workable in other situations. This could be a platform through which you access a rumble. Or a cover to a hidden/secret area. Or say the top part of the hole in a track like Anarchy in Wonderland. It can be textured to match the surrounding area and made hard to see. A hidden entrance or a booby trap.

> I have a new track idea, but it would take a lot of work (think "solving a puzzle" and "Mystery House")

lol, I have no idea what you mean.

Lol...I too hung up a few tiimes....

If you think you may have a use for it, then I wil develop the full version (this was a low-detail test model).

But I have a new observation that may put a damper on things....


I redid the ramp slightly to let the truck impact harder, resulting in the front of the body striking the paper head-on, rather than the tires underneath the truck hitting first as the truck's nose tilts upwards.......guess what?......no reaction from the paper.

It now appears that the TIRE models must strike the animated model to activate the top-crush effect.......careful track design will be very important to be sure the trucks hit correctly.

Perhaps the hoop can be tilted top-backwards a bit, so that the hoop is tilted back 45 degrees or so, to guarantee tire contact.

Let me know if you still want the model despite this limitation....I'll add it to my project list.

> It now appears that the TIRE models must strike the animated model to activate the top-crush effect.....

That wouldn't prevent anything I was describing.

> Let me know

However, I'm swamped. Good ideas are always worth consideration because you never know when you'll come back to them. I'm not ready to begin a new track at the moment, but this is not wasted material. I've saved your zip for future reference, and maybe you should leave it posted for anybody who comes along and wants to add to the train of thought here. It's all good.

btw, I have another track idea on the table too that'll take a while to get to, and another lurking near by. The best part is there's no shortage of ideas :-)

OK, sounds good.......At least the concept is out and circulating...let's see if anything sprouts from it.

Meanwhile, one workaround is to tilt the surface back a bit, to improve the chances of a tire impact....

a benefit is that the truck tends to sit on the surface longer, causing the paper to "tear" a bit more than before on a single impact...if the truck bounces a bit, even better tearing.

Here's the last version, with re-shaped ramp and tilted paper hoop.

http://mtm2.com/~bigdogge/download/test ... d-hoop.ZIP


...Could be nice for a 3-ring circus track beneath a big-top tent (hint hint).


Another idea...a wood bridge that collapses into a pre-defined "broken" shape......hmmmm.

Very cool trick BigDOGGe! (somebody get him a new squeeky toy or something, clown shaped perhaps)

But seriously, very well done. I've been wanting to see what could be done with top-crush and this sort of experimenting is great to see. Regarding top-crush my <a href=http://forum.mtm2.com/viewtopic.php?t=1188>previous</a> comment still stands, but if you click the "here" in Phin's followup you may like to check out what's there just for kicks - top crush without any models assigned to it, the original example from TRI if you've never seen it before.

Thanks for the link, Wint. I only wish I could see anything (arrgh!)

The mtm1 hillclimb track only allows 4 camera views (racecam, chase, chase-near, and blimpcam) and the racecam view seems to be in the cockpit? I can't get an external side view.

I tried observing from the side in Replay, but the cars are already crushed before the truck reaches it...LMAO!

Too bad the second Bin in the crush model animated bin can't itself be an animated bin.....then you may be able to put an animated object in motion by contacting it....it's worth exploring deeper.