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Controlling stuff by disabling XPresso is not the best method IMHO, but you could either keyframe the enable checkbox in attrib manager, or make a second XPresso control window, drag your main XP tag in and use the enable port. In this snip the compare <= gives a 1 for upto F25 for enable, then a 0 to disable.It's a bit more flexible. I'd suggest stopping the follow inside your code - post your scene and I'll have a look. If it's a big scene (or has copyright models etc) strip it down to the relevant part.

I thought that's what the poster meant, although in my little (theoretical) test the string length changed by about 5% when stretched, so if my assumptions were correct the string diameter would only change by 2% - would you even notice a 2% change ? A rubber band gets thinner when you stretch it . . . I 'bow' to your superior knowledge on the subject.

I'm guessing that a string gets thinner when it is stretched on a bow, and the volume is constant. I think the vol of a string is the cross section X length ie volume = pi * R^2 * L so if the volume is constant, R is proportional to the square root of 1/L - so doesn't change much. Try pulling the center point on this 'string' spline - there's an exaggerated circle for comparison. It hardly varies. https://www.dropbox.com/s/disr7u4vjk82on6/bow.c4d?dl=1

Probably easiest to make a separate control XPresso window where your switch drives the enable port for your main XPresso. https://www.dropbox.com/s/m95k4ithd5tv9f8/enablexp.c4d?dl=1

I hate to say this graphos, but I've wasted your time here - that code is too advanced for me to understand, although in a way it illustrates the problems I have with Python. There's a ton of tutorials on YouTube and elsewhere that will teach Python from print('hello world') and up. That's how I am learning regular number-crunching Python. There doesn't seem to be anything explaining C4D-specific Python that starts at 'hello world' - it's either the MAXON manual or nothing, and the MAXON book might as well be in Russian. If I were to type any of the terms in your code into the MAXON website search box, the results would be meaningless to me. TBH I can't tell which are your vars and which are reserved words. It's the same at StackOverflow - you need to be an advanced coder to understand the answers to questions posted by noobs, which sort of defeats the purpose of a forum. As usual, there's an XKCD comic that sums it all up.

@graphos could you give an example of your basecontainer method - sounds interesting.

Same problem with frame dependent on or off. I've noticed a similar thing when I want to print to console for debugging - there has to be an output port connected to a result etc to get a print (although removing the Python output port lets me print). It's no big deal having an extra unwanted port - just puzzling. Maybe it's not a bug - it's a feature, as the saying goes.

Does an XPresso Python node need a connected output port to function correctly? I have a flying helicopter WIP that started life as an XPresso Python node with user data slider inputs and position etc output ports. It worked OK, but I decided to have a go at putting everything in the code ie reading my slider data and writing position + rotation vectors to the helicopter - no ports at all. Trouble is, it kept locking up - and intermittently at that. I thought it was my code, but after a lot of tinkering (trial and error) I found that having a 'dummy' variable connected to a result node - see snip - more or less guaranteed a flying helicopter. I tried a fix I read somewhere about c4d.EventAdd(), to no avail. I also tried copy/paste into a Python tag, but got even weirder reults - when I stopped the timeline, my helicopter kept flying ! Any insights into this output node mystery appreciated. Here's the WIP file - it has a bit of smoothing on the variables to make the aircraft react less jerky to the controls. File's 11MB due to some textures. https://www.dropbox.com/s/muln5vt8o3j4t0j/helicopter7.zip?dl=1

I could be being generous here, but I'm sure sometimes a noob is overwhelmed by the answer and feels a bit embarrassed to say 'can I have that in English'. I realise it's hard to guess the level of knowledge the enquirer has, but if the noob question is 'how do I make this cube look nice?' and the reply is 'use a matrix fracture with a Voroni object and turbulence noise in the reflectance alpha channel with PLA set to negative infinity with a spline deformer mapped to a random vector using Python', the noob will think 'maybe C4D isn't for me'. You see replies here that just say something like 'use a step effector', and I think if the guy knew what a step effector was and how to use it he wouldn't be asking. I've got to admit I'm guilty of both blinding people with science, and being ashamed to ask for a better explanation. Maybe ashamed is a bit strong, but you get my drift.

Thanks for comments. The math is based on how I generated the movement - both spacial and H rotation - of the helicopter, by adding a small value every frame. By varying the amount added, an object can speed up or slow down smoothly. This is a topic that crops up here from time to time when discussing rotation. Generating a rotation angle with angle = time in secs * a constant is fine for constant speed, but changing the speed by varying the constant usually results in the object going backwards or just glitching. Getting the angle by angle = angle at last frame + delta allows for smooth speed change by varying the delta. You can do this in XPresso usually needs zeroing at F0 or in Python def main(): global x frame = doc.GetTime().GetFrame(doc.GetFps()) # get current frame if frame == 0: x = 0 else: x += speed # increment x by speed the XP and the Python are evaluated once per frame, although when presented with the concept of x = x + 1 most folk go WHAT ?

I've been having a bit of fun today doing the math to fly a Lego helicopter I got from Google's Sketchup 3D Warehouse, so I thought I'd share the file. The file's 11MB because there's some tex for the background mountains. I made a short video to show how it works scene https://www.dropbox.com/s/tcnzx19uqtyucg9/helicopter.zip?dl=1 there's a bit of info in the XPresso remarks.

what is TD and TDMSC ?

Shameless plug for some of my pendulum stuff on Vimeo - Newton's Cradle, 100 pendulums, 8 pendulums and a 3-way jointed pendulum.

Am I missing something here ? What's wrong with a sweep, a circle and a rectangle ? doesn't matter if the rectangle is closed or not - the base hides it.

Was surprised to see this the other day - only kidding - I re-inked yesterday's XKCD strip. The original is here. For people who don't know what I'm on about, XKCD is a 3X weekly comic strip about computers, programming, physics and nerdy stuff in general. There's an 'explain xkcd' site for all the strips eg for the above here, where I often find hidden references in what I thought was a simple joke eg the above strip alludes to the Alan Turing film The Imitation Game (which I'd missed). It's quite hard to find a good comic font - I used VTC Letterer Pro for my re-inking. 2 of my XKCD favorites - GOTO, and Code Quality https://www.xkcd.com/

I loaded the preset, but for some reason couldn't see the contents. I unpacked it, and it seems to be 2 compares - is #1 lower than both #2 and #3. I replicated that in this file and it seems OK https://www.dropbox.com/s/263gawpledqc81h/2compares.c4d?dl=1 BTW - I'm out of my depth with baseobject-type python - I just do the regular number crunching variety.

A bit out of my comfort zone with base objects, but by trial and error I came up with this def main(): global x, y, z, position position = obj_in[c4d.ID_BASEOBJECT_REL_POSITION] x = position[0] y = position[1] z = position[2] seems like you can treat the position vector as a list and extract items. You might need ABS not REL. https://www.dropbox.com/s/1nmdpjwi9x3x87n/vector.c4d?dl=1 BTW did you post the wrong file ? post the original so I can have a look at the problem

Since you are a bit new to rangemappers (and possibly XPresso), maybe I should point out how % works in C4D (you have probably sussed this out already, but might help someone else). If you have RM input and output ranges set to 0 - 100%, and input say 50% from a slider or other node, then hang a result node on the output it shows 0.5 not 50. This because XPresso treats % as a decimal 0 >> 1. It confuses some people the first time it happens - double checking your math etc. A similar thing with degrees - if both RM ranges are set to 0 - 360 deg, and you input 30 deg, a result node on the output shows 0.524 because XPresso uses radians (2 * pi radians = 360 deg, 1 rad about 57 deg). For these reasons, I prefer to just use decimals and radians for my XPresso stuff then I know exactly what's what. A lot of C4D users think they have to use the degree node to (unnecessarily) convert degs + rads back and forth when using XPresso for wheel rotation calculations etc. There's no need - when you use degrees (or %) in the GUI, XPresso just converts them anyway.

Are you saying the rangemapper is calculating outside the range - have you got clamp checked ?

I see why you used 2D now. In fact I'd never noticed that 2D vector option in user data - so I learned something today as well.

Your file has a heap of stuff I don't seem to have. This is how I'd do random speed on a spline, using noise - it's smoother than random numbers that jump all over the place every frame. https://www.dropbox.com/s/gqtw4im42g0spk3/rndvarspeed.c4d?dl=1

Not sure why you are using 2D, but here's a 1D file. I think you are getting invert and negate mixed up> Invert is reciprocal ie 'one over' 1/x. Negate means multiply by -1. There's also a reverse checkbox in rangemapper. Percent often confuses people - percent in the XPresso window is actually decimal 0-1 eg 35% is .35 . Same goes for angles - degrees in GUI, radians in XP window. I prefer to stick with the units used in the XP window, then I know where I'm at. Some 1D teeth https://www.dropbox.com/s/watezvyegz5go68/teeth.c4d?dl=1

This is a project that came to being thanks to a free model from SketchUp. I've an interest in electronic traces on screens eg Lissajous curves, spirograph traces etc and needed an oscilloscope to display an audio sweep. Turbosquid wanted $100-200 for a really nice 'scope, but luckily I found a half decent one free on SketchUp that was usable with a few tweaks. The next problem was the math. The human ear is logarithmic ie works on powers of 2 (octaves on a piano is a doubling of frequency), so I wanted to use a log frequency sweep (linear just sounds wrong). I delved into exponential math and came up with this. The display and digital readout correspond quite well to the frequency heard. Screen is a movie used as a mat, font is Digital Readout Upright. 10MB file for screen https://www.dropbox.com/s/bfmfps9emp8dwtv/sweep.zip?dl=1 audio tone/sweep generator free from here just a bit of fun really

I don't think I've seen it mentioned here before, but I found a source of free 3D models yesterday - SketchUp 3D Warehouse. Seems to be a place where hobbyists upload their stuff, and reading through the T & Cs it looks like you can use the models for any non-commercial use. Here's a free computer I found I got a couple of semi trailer rigs, and there's also some half-decent city scapes eg NYC here the sketchup files have skp extension, and you can just drop them into cinema, although I've found that if there's a choice of versions an older one (say 2014) works best. https://3dwarehouse.sketchup.com/index.html apologies if this is old news - it's new to me

@SolarPH what I meant was - something like: I need to control a light so that switch A does this and slider B does that. Your simplified version is your solution to whatever the original task was. Trouble is, I can't work out what the original task was from your solution. I'm also not sure what C motion has to do with things. A simple bit of python in a node can often be a solution to a complex truth table type xpresso problem. Not number crunching, just something like if A > B and C < D: output = blah elif A == B and D > C: output = blah blah else: output = fall back default if you get my drift