[Brian Jones]

I agree, it looks like Broadcast has only Rigid Body without connectors etc. But I don’t have broadcast either. Would be easy with Studio, without it (and without the AE solution) it is possible with dynamics to make a chain (with links) it is slow and very touchy but can work but it’s a chain not a string. Would be possible with bones/joints but dynamics in joints ‘self damp’ if set up like you’d need for a string and it would look wrong (unless someone wiser knows how to defeat that).
Without another solution I’d probably do it by hand, the old way, dynamics take the work out and add realism not possible with lots of objects but a card on a string should be possible to do by hand and make it look ok.

[Brian Jones]

found it – in the Timeline window View/Show enable “Show Min/Max Values” – that adds a dashed green line at the min and max values and you can grab either min or max and scale. Scales toward/away from the other line not both toward the center.

[Brian Jones]

it looked promising but the help says you are correct, just the f-curve is changed without changing the actual values – it’s to enable you to have f-curves with wildly different values all be visible at the same time. Can’t find an actual value scalar on a second quick search.

[Brian Jones]

select the tracks you want to scale and in the AM you should see F-Curve Offset and F-Curve Scale

[Brian Jones]

Collisions are a problem, yes. increasing the subsampling has to help (in the expert tab) but also increasing the number of points. It slows everything down but it’s a better chance for accuracy.

I don’t know about soft bodies haven’t tried anything quite like that in a soft body. They seem intended for round things (or at least ‘volumes’). However that being said they also handle collisions pretty well. I’ll try a test just to see what happens.

[Brian Jones]

cloth was created for cloth on a character, collision with the character is important but self collision is not even turned on by default, and your sim requires it. Same for stiffness it was setup for clothing not with the kind of materials in a camera strap in mind (I’m guessing).
Your sim is more similar to cloth dropping in a pile, self collision is absolutely necessary but in reality cloth is billions (trillions?) of points colliding, it would likely be more accurate with tons of vertexes but the performance hit is massive…

Rather than bones I’d try to model it so it’s already in position rather than moving it into position. Right now, if you look at the movement of the cube (up close) it jumps from frame to frame (like it has to) to it’s next position (for that frame) and the cloth *jumps* to try and catch up, it’s no wonder it has too much energy…

Flexion is stiffness, torsional stiffness – the image in the help for Flexion makes it clear (I think) it does get stiffer as the Flexion value goes up (not down)

[Brian Jones]

subdivided the long polys (the thicker bit between the end and the fat part of the strap), added a vertex map so some areas are stiffer (the transition areas particularly where there are vertex’s so close to each other).
Turned down Iterations (more than needed). Increased Air Resistance, set Global Drag to a constant 1%. Turned on Self Collision in the Expert Tab and increased it’s sub-sampling a bit, rotated the moving cube so it ends up the right rotation when it ends (don’t know if that helps). Lowered Stiffness and increased Flexion (actually a form of stiffness) and added some Rubber so it can stretch a bit a take up some of the energy (all modified by the Vertex map). Decreased Bounce in the strap, you don’t need extra energy in the sim maybe even 1% is too high.
Don’t know if that’s what you need and maybe Softbodies would be something to investigate but FWIW…

9731_clothstrap3.c4d.zip

[Brian Jones]

I have XP3.5 so for what it’s worth the help there says
“You can use the Dynamics engine first introduced in Cinema 4D R12 with X-Particles. To do so, you must:

add a Generator object or a Sprite object to the scene and link it to an emitter (you must generate objects for Dynamics to work, the engine will not work on bare particles)
if using a Generator object, add an object to be generated; if using Sprites, select the type of sprite you want – note that this will not work if you generate lights, since they have no geometry
set up Dynamics tags on the objects you want particles to collide with in the usual way
add a Dynamics tag to the Sprite or Generator object, NOT to the object to be generated – this is important!
set the required options in the Dynamics tag
finally, in the Dynamics tag, Collision tab, set ‘Individual Elements’ to ‘Top Level’ (or any of the options in the drop-down other than ‘Off’) – if you don’t do this you won’t get any dynamics effects
Now your particles and their objects can be used with the inbuilt Dynamics system.

You should be aware that Cinema’s Dynamics will take control of the generated object away from X-Particles. The particles themselves remain under the control of the emitter, but the objects may be completely divorced from their source particle. Unfortunately there is nothing we can do about this, as the Cinema 4D SDK does not provide any functions for controlling dynamics or accessing the dynamics data.”

It’s possible with XP3.5 but if it does work with 2.5 you’d have to go to Project/Dynamics/Gravity to 0 since trying to set the Mass of your spare to 0 won’t work it will still drop when your collisions do work.

[Brian Jones]

when you plug a value into the xpresso port of a parameter in your light (or any parameter) you should notice an arrow in the keyframe dot – it indicates there is xpresso driving the value. If nothing else is changed the xpresso gets listened to not the keyframes.
But you can add the light’s intensity (I assume you are using intensity) in the xpresso by using the intensity Outport from the light node and add the xpresso value (I assume Noise) to that. Then plug back into the light’s Inport – that way the keyframe’s value and xpresso can be added together.
Here’s an example with that – it also has the noise being multiplied by the light’s up-ramping intensity so the light starts off and then flickers as it ramps up, then some code to add the noise calculation if the light’s intensity is less than 100% (1) or add nothing after that so the light stabilizes at 100%.

9723_lightflickersasitturnson.c4d.zip

I left two nodes from my first test as an example there is usually more than one way (is the animation at less than an 30 frames? – where the keyframed values are for this test but I figured your lights will be turning on somewhere down the timeline and maybe not altogether so why not use the light’s own intensity to control whether the flicker occurs or not)

[Brian Jones]

I wouldn’t think you’d want python to interact with xpresso in this case, only with the material