I’m having a bit of heartburn with this one. I’m trying to use reactor with a crane equipped with rigging slings. It will rotate around and boom up lowering the blocks (Hook) to an object and then pick it up. I have unyielding dummy Block geometry for reactor and they are linked to the actual animated parts. All of the rigging is ether dummy low poly parts for reactor or reactor ropes. I’ve been able to get the ropes to operate fine but the master links on the hook pulls through the hook when it starts to pull the rigging along as if the rigging is too heavy for the hook to support. I’m trying to get a realistic motion with the ropes and rigging. I’ve made many changes to the mass and other settings without effecting the results. Can anyone of the reactor master minds help me with this? I want to learn and use reactor whenever I can, but it just seems to quirky.

Also, when reactor says the density looks very low, can you increase this or is this the mass setting?

D.R.
3ds Max 2009
Autodesk Inventor & AutoCAD
HP xw8600 Workstation
Windows XP Pro 64Bit
Dual Intel Xeon 2.83 E5440 GHz
8.00 GB of Ram

Can you upload the scene with the reactor parts?

And the density being too low warning is fixed by increasing the mass, because density is the amount of mass in the volume of the object.

3ds Max 2010 SP1
Windows 7 Professional 64-bit
Dual Intel Xeon E5520, 6 GB Ram
NVIDIA Quadro FX 3450

This is it.

D.R.
3ds Max 2009
Autodesk Inventor & AutoCAD
HP xw8600 Workstation
Windows XP Pro 64Bit
Dual Intel Xeon 2.83 E5440 GHz
8.00 GB of Ram

	Attachment
reactor_crane_hooks_01.zip

D.R. 03 November 2009 01:20 PM

I’m having a bit of heartburn with this one. I’m trying to use reactor with a crane equipped with rigging slings. It will rotate around and boom up lowering the blocks (Hook) to an object and then pick it up. I have unyielding dummy Block geometry for reactor and they are linked to the actual animated parts. All of the rigging is ether dummy low poly parts for reactor or reactor ropes. I’ve been able to get the ropes to operate fine but the master links on the hook pulls through the hook when it starts to pull the rigging along as if the rigging is too heavy for the hook to support. I’m trying to get a realistic motion with the ropes and rigging. I’ve made many changes to the mass and other settings without effecting the results. Can anyone of the reactor master minds help me with this? I want to learn and use reactor whenever I can, but it just seems to quirky.

I noticed a couple things when looking through your file:

1) Your reactor world scale and gravity seem to be way off. Reactor works best when your scales and weights are accurate. I changed the gravity Z back to the default -32’2 6/32” or -9809.162mm, and the world scale 1m = 3’3 10/32” or 998.537mm. That seems to fix your density warnings as well. I also increased the collision tolerance to around 1”, or 25mm.

On another note, not sure if you’ll get better results with feet/inches than millimeters. I think I heard about reactor not working correctly with centimeters once or twice though.

2) Also with the scale, I don’t know if these pieces are to real world scale, but you should make them so they are, and give them an appropriate weight. Some chain pieces are about 16” tall right now, which is fine if that’s how tall they would be in real life. I also noticed you scaled some of the chain links and the hook so they aren’t at 100% scale. You might want to scale them at the vertex level, or use the Reset Xform to make them 100%.

As for the chain links going through the top hooks, it’s probably because they’re interpenetrating when you started the animation. You might want to make the links slightly larger to give them a little more room for the collision tolerance.

Hope this helps.

3ds Max 2010 SP1
Windows 7 Professional 64-bit
Dual Intel Xeon E5520, 6 GB Ram
NVIDIA Quadro FX 3450

Thank you for looking at the file and the very valuable comments. The world scale and the tolerance has always been a question mark for me. It seems to be so hard to figure out what these setting need to be from project to project. Everything is actual scale, the parts that appear to be chain links are dummy objects to link a shackle to. The master link at the hook didn’t look like it was intersecting to me but that’s why your input is so priceless. You know there’s just not allot of reactor help on the internet. I take it that the default world scale is what should be left alone, and then just tweak the tolerance. I heard the gravity should be set 10 times the world scale in the negative z axes.

How can you keep the rope from reacting like it’s under water. These are cables on the crane and they seem to have allot of drag. I had placed the gravity high to try and get them to move faster and not get left to far behind the hook when it moves.

D.R.
3ds Max 2009
Autodesk Inventor & AutoCAD
HP xw8600 Workstation
Windows XP Pro 64Bit
Dual Intel Xeon 2.83 E5440 GHz
8.00 GB of Ram

Also is the Weight figured in the mass? If so are the units the mass uses in a specific unit of scale for weights calculation, and do you have to give the rope mass to strengthen it enough to handle the load?

D.R.
3ds Max 2009
Autodesk Inventor & AutoCAD
HP xw8600 Workstation
Windows XP Pro 64Bit
Dual Intel Xeon 2.83 E5440 GHz
8.00 GB of Ram

D.R. 03 November 2009 06:49 PM

Thank you for looking at the file and the very valuable comments. The world scale and the tolerance has always been a question mark for me. It seems to be so hard to figure out what these setting need to be from project to project.

I would leave the world scale to the default, and you only really need to change the gravity if you want objects to fall faster, slower, not at all, etc…

How can you keep the rope from reacting like it’s under water. These are cables on the crane and they seem to have allot of drag. I had placed the gravity high to try and get them to move faster and not get left to far behind the hook when it moves.

Some of your ropes have a very high air resistance of 10. Try lowering those to in between 0.1-1.0 and see if that works.

Also is the Weight figured in the mass? If so are the units the mass uses in a specific unit of scale for weights calculation, and do you have to give the rope mass to strengthen it enough to handle the load?

The mass is the weight and it’s measured in kg, so you have to take that into account if you’re used to lbs or whatever. The rope should handle any load, it shouldn’t break or anything. Giving it weight should just affect how it moves through the air.

3ds Max 2010 SP1
Windows 7 Professional 64-bit
Dual Intel Xeon E5520, 6 GB Ram
NVIDIA Quadro FX 3450