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This makes a cube visible when link is present https://www.dropbox.com/s/arqibkx1hi8p7hb/linktransfer2.c4d?dl=1

I think this does it, link is python node input from Null A link (ie Null B) import c4d #Welcome to the world of Python def main(): null_A = doc.SearchObject('Null A') if link: link[c4d.ID_USERDATA,1] = null_A[c4d.ID_USERDATA,2] link[c4d.ID_USERDATA,2] = null_A[c4d.ID_USERDATA,3] link[c4d.ID_USERDATA,3] = null_A[c4d.ID_USERDATA,4] I used if link because get yellow node error if no link present https://www.dropbox.com/s/uqrkqtyt64bjlna/linktransfer.c4d?dl=1 no guarantees - I'm also a bit of a Python novice edit - to get the correct userdata syntax, I just typed in null_A and dragged the relevant name in from the GUI.

Here's a rangemapper with this ease-ease spline - the spline represents input as X 0 - 1, and output as Y 0 - 1. You make points by ctrl-click - make sure start, end are on 0, 1 etc. Upper and lower must be clamped, or RM will calculate an output when outside the range. I used frame, but I think secs would also be OK https://www.dropbox.com/s/489z0asxthr9nl6/easemapper.c4d?dl=1 edit: just ease in, starts at 0 https://www.dropbox.com/s/sqcvar61wgg92yh/easein.c4d?dl=1

Yes it would be useful - that's what the rangemapper is. Can you explain the difference between what you are describing and this - utils boxstep does this in Python, or you could write your own with if, elif, else etc but that is just re-inventing the wheel.

I'm still not sure why XPresso rangemap doesn't do what you want - it has spline control. There's a Python equivalent Boxstep and an eased version Smoothstep - both map to 0 - 1 details (utils clamp just clamps). I noticed your Python maxoutput is 100 - you do realise that 0-100% for spherify (or anything) is actually 0-1 decimal ? Also GetActiveDocument is not required since doc is a built-in variable.

It's not very clear what you mean by clamp step by step - your file is already proportional between F25 and F50. Do you mean 100% in that range and 0% outside ? In XPresso that's just xpresso version https://www.dropbox.com/s/kju18ew7gbko25t/testxp.c4d?dl=1 python version https://www.dropbox.com/s/lf4mr4usmz1j5u6/testpy.c4d?dl=1 more info required . . .

If you just need to tweak the settings whilst setting up your scene, you could always 'tear off' the panel by clicking the + icon - you can have as many of these as you like

You are mapping 2D to 1D, so you need some trig. If you divide the spline point data Yt / Xt this gives you the tangent of the angle of the spline. Taking the atan of this gives you the actual angle. Dividing by 90 gives a %, take that from 1 and you have a number for the bias. https://www.dropbox.com/s/kbt0smfdeeso6ti/mapping.c4d?dl=1 maybe . . .

Can I just add that, unlike a lot of the free 3D models that are online (eg cars, trucks), the Turbosquid drones I bought were the correct C4D format, had sensible hierarchy with English names (ditto the mats) with all the axes centered and aligned - including the propellers, camera etc. Just need a bit of XPresso math to make them go.

I'm sure a lot of you guys have used Turbosquid in the past, but last night I decided to try them out for the 1st time - I bought a couple of quite decent quadcopter drone things for about 25 Euro. The thing that made me laugh though, was when I clicked 'buy' and a warning popped up reminding me I was buying a c4d model not an actual item. I had visions of someone googling 'remote control helicopter' eg for a childs Xmas present, finding a nice one for $400 at TS, clicking buy and when it said 'downloading . . .' going WHAT ? It must have happened at least once for them to have that disclaimer.

Sting makes his first post at C4D Cafe explanation well it does say off-topic, light-hearted + fun

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 ?

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.