Cineversity

Dr Sassmannshausen,

Hello.  I’m having a problem with the Xpresso_101_01_User-Data lesson and am hoping you might help.  I’m able to create sliders to control position, rotation and even change the color, but scaling doesn’t seem to work.

My set up for the data slider is as follows:

Data type: Float
Interface: Float Slider
Unit: Real
Step: 1
Limit Min: 1
Limit Max: 1000
Default Value: 200

In the xPresso window, the output of this slider is linked to the cube primitive’s input for Object Properties > Size > Size X, but it does not work.  I tried different units (like meters & percent), but these do not work either.  I remember learning somewhere that the scaling method in C4D changed between two versions and was wondering if this might be the issue here…

Thanks for your help.

Jerome Olivier

Thanks a lot, JeromeOliver, for the nice feedback.

There are two main things in XPresso that needs to be known 1. the data type that flows along the “wires” and 2. the nodes

One can’t really work without the other.

To know what is expected from each node input, you can place your mous indicator over the that “dot” (input or output) and in the bottom part of the XPresso Editor you will find the needed information.

Another idea is to connect the output of an object (for example) with the “Result” node (New Node> XPresso>General>Result) and while moving or rotating the object in teh editor view, you get an idea what “numbers” are created. I mention it, as sometimes a full rotation is “two Pi” (2x 3.14’) and sometimes it is expected in degree. Confusing, but solvable that way.

If a vector is expected—but a real value is given into the input for the vector, the real value will feed all three vector values! Attention is mandatory here, but again the bottom line informs you.

The step value might be ok, too small or too large. Similar to the Limit max. It all depends on your needs. If the slider needs to be moved for values between 2 and 7 for example, the setting of 1000 for the limit amx will make it really hard to move the slider precisely. I think you get the idea. If you need that large but also finer values, you can always set up two sliders and combine them mathematically.

I have attached a S.X user slider set up. Please note that this will be broken in the moment the cube is made “editable”. Let me know if there is another question or set up you like to try. I’m happy to help.

Perhaps we should open a Cineversity Q&A forums post for further questions, as this is the Tutorial Suggestion Forum. Thanks for considering.

All the best

Sassi

P.S. the User Data is set up at the Null, you can also set up User Data on the Cube, or even on the XPresso Tag itself!

Oops!  My bad.  Again, another typical newbie error.  I accidentally selected the output of the null’s scale, instead of the user data scale.  Lesson learned: always make sure to select the proper output, or better yet, use the xPressoMaker script to create the user data output ports automatically and avoid this silly mistake.

Onto lesson two.

Nice that this is cleared, Jerome Olivier.

During the learning phase I would suggest to avoid any automatic stuff. Seriously, as it keeps your knowledge flat. Every mistake you make will help you to get things working in the future. This is the time where you set up a good base and there are not really mistakes that you do, only feedback is given. Doesn’t work, OK, a chance to get more knowledge about.

Embrace the mistakes, celebrate the solves. Ignore the losses. ...and soon you will have mastered it.

My best wishes for your next explorations

Sassi

Wow!  Thank you for getting back to me so quickly.  I must’ve been typing my post when you replied.  Again, sorry for the silly mistake.  I’ll try and be more careful in the future.

Haha!  Again.  ;^)

I was just typing… when the new one came in. Thehehe. Perfect :o)

Again, there are no silly mistakes. Any mistake now will help you to “de-bug” a more complex set-up later on. Perhaps I copy and paste this, as we crossed our posts, as I find it important:

Embrace the mistakes, celebrate the solves. Ignore the losses. ...and soon you will have mastered it.

Thanks for letting me say it twice. ;o)

Enjoy your weekend

Sassi

Hope it’s okay to post homework.  Maybe someone will find them useful?

Lesson #3, Matrix.

Even after watching the video three times, it’s a bit confusing concerning the difference between scale and size.  I created a small scene to help wrap my head around the concept of the matrix, though I’m not 100% sure I fully get it.

Hi JeromeOliver, we need to change the forum soon, this is not supposed to be here. Other will not find it, as it is a Tutorial Suggestion, not a Cineversity Q&A. It sounds perhaps trivial—but after a while the complete forum would be just noise if we keep things not organized.

The Matrix. It is certainly even in Hands on classes a part of information that has a longer digesting time.

The simple way to explain it is, from the four you have one for the position in space: The Offset. That is pretty simple I guess, as it is similar to the position of an object.

The other three are—well, some will say more abstract. Lets start with one of the X,Y,Z arrows that you see when you select an object in “Move” mode. The red, green and blue arrow. OK, each them represents an vector, Vectors hare based in photographic terms on a point of view (where the camera is) and a point of interest (the subject to be photographed). between the two points you will have a distance. with this information, one will get a vector (or arrow if you like).

To define two points in space you need for each point three positions: X,Y and Z. To have not for each arrow or vector six numbers “Point of View XYZ” and “Point of Interest XYZ”, they all share the Offset XYZ values, the origin, or the first vector in the Matrix.

As these arrows are not always perpendicular to each other, nor have the same length always, these three values define the end point of the vector (point of interest—if that helps)

In that way every single object is defined in C4D. It has a position and how it is scaled or rotated will be expressed with these v1, v2, v3 or the three other vectors besides the Offset.

Any rotation or scale is expressed that way. I try normally to explain it that each vector X, Y or Z is defined by three invisible “sub-vectors”

This is the most complicated to grasp format in XPresso, and I haven’t seen a lot of people in the past ten years who got it in the first moment. The reason that I see for that is the image of the XYZ axis system and the idea that we talk on C4D surface in PSR (Position, Scale and Rotation) values, but internally it is translated in the Matrix. It is the base of the calculation inside of C4D.

I hope I could put a little bit more light on it.

Let me know if that has helped.

All the best

Sassi

jeromeOlivier - 10 August 2014 02:56 AM

Hope it’s okay to post homework.  Maybe someone will find them useful?

I quoted it as I went out of order, in believe that the Matrix question was more of your interest, and made more sense to answer that one first.

I think I have not to comment on any of these, as I see your fast progress in this. Well done. I have the feeling you get the idea and you move quickly forward.

In file three you have already done what I would have suggested for file two. The Subtract Node can be set to Vector, and in this way, you would have saved two nodes. Again, I saw this already applied to scene three, so no critic, just a little hint—just in case.

You see how much time you can save by using a Vector format instead of three “Real” values. Now comes the idea why I have answered the Matrix question first, because you get all PSR values (which are nine values in the User Interface normally) in one format: One wire, one connector. Simple and powerful. Leaves me only to point out the significance of the separation in Global and Local. :O) You will get there soon I guess, just to make you aware that there is a difference.

Have a great Sunday

Sassi

In file three you have already done what I would have suggested for file two. The Subtract Node can be set to Vector, and in this way, you would have saved two nodes. Again, I saw this already applied to scene three, so no critic, just a little hint—just in case.

Good catch, thanks for pointing it out.  I made the modifications and you’re right, huge savings in terms of nodes…

You’re welcome, Jerome Olivier. :o)

Dr. Sassi - 10 August 2014 02:07 PM

Hi JeromeOliver, we need to change the forum soon, this is not supposed to be here. Other will not find it, as it is a Tutorial Suggestion, not a Cineversity Q&A. It sounds perhaps trivial—but after a while the complete forum would be just noise if we keep things not organized.

I never responded to this, sorry.  Will the thread be moved to the Q&A section of the forum, or should I start another thread?

Thanks for this, Jerome Olivier.

The idea is that people can find what they are looking for. As we have no limitations in the number of threads, we could go theme by theme if you like.
A thread should have a clear question or theme, and if that is done, the thread should be left alone. Otherwise it becomes really hard to find anything in the future.

To have a discussion about functionality in the “Suggest Tutorials” forum is certain not ideal. Hence why I suggest to move.

So: Yes, please, if there is a question, please open a new thread.

There are two main groups who read the information here (I assume) people who just check for random information or people on a deadline with a question. Imagine to have a deadline and the threads are misplaced and noisy with digressions.

I like to help here if you have a question or any doubts about a function. I go with the idea that anything that is not clear will slow down the progress of learning in the future. Many tutorials that I spotted elsewhere are not designed for that idea of learning, they target a fast result and leave the user like a swizz cheese, with many holes. Not my taste, either way ;o)

So, please feel always free to ask, I will try to answer, or someone else from Cineversity. The more comfortable your feel the more fun you have with C4D, the better your results will be and that will reflect back to everything.

Have a great Sunday

Sassi

Understood.  Will continue in separate threads with clearly marked titles.

Thank you, Sassi.  And have a great Sunday too.