Problem registering multiple sequences - SOLVED


#1

My goal is to do a morph, from a simple arrangement of objects to having more in the scene, to simulate things being added. All of the objects are on a turntable and the camera is on a short path.

OPTION A: Would be the easiest way, but will take over 60 hours.
OPTION B: Is what I tried to do, but none of the sequences line up or register.

SOLUTION TRIED: I turned off tweening for both the camera’s position, target, and object’s rotation (using a proxy). It should be perfectly linear animation. Therefore, frame 50 from one sequence should be identical to frame 50 from another sequence.

PROBLEM : They never line up!

QUESTION: What is causing the camera position --or-- rotating geometry – in one frame 50 to not be the same as another frame 50???


(Luc Adriaenssen) #2

Dave,
I don’t understand exactly what you’re doing. I grasp that you are making various sequences which are compiled using some video editor according to scheme B. Correct? Question is how the sequences come about. Are they the result of the one Rhino/Bongo model, or multiple? How many frames counts every sequence, 50 or more? Isn’t, in your scheme B, frame 50 of the first sequence frame 1 (or 2 or 3 …) of the second? Seemingly it would be in scheme A!? Please some clarification.


#3

I am doing a ‘morph.’ At several intervals of time, there is more geometry in the scene. It simulates things being added.

Each layer is a sequence of stills from Rhino+Bongo+V-Ray and imported into After Effects. Think of it as a short video.

All sequences are from the exact same model. After each sequence is done, I turn on another layer and render the next sequence. You can see the actual frame numbers in Option B. These are absolute tick/frame numbers from Bongo and SHOULD BE the same, regardless of (a) when I start and stop a sequence or (b) which layers are on or off.

This process is actually pretty common to show a scene fade from a wire-frame to a shaded view to a rendered view, all while stuff is moving. I’ve typically done version A and just made each sequence equal & full length. In After Effects, I then transition (via opacity fade) from the top layers to the bottom layers.

See image with more stuff.

The problem is that frames with the same number should be identical, except with the new layer stuff. They’re not. They’re from a radically different position. It’s like there is tweening happening to each short sequence, when I have turned it off / changed to linear.


#4

I think I have the solution. It’s the difference between ticks and frames … and how one tick refers to an absolute position while frames are more relative AND can be scaled independently. (One tick = 7.5 frames? Sure!) I never ran into this before because I always have rendered the entire timeline.

An example: you want to render from tick 30 to 100 on the timeline, for a total of 71 ticks OR frames. But, the Active time segment, in frames, goes from 0 to 70. Makes sense? Didn’t think so.

Here are the steps:

  1. Open the Bongo Render Animation dialog
  2. Under Input, select the exact start tick and stop tick, using the timeline.
  3. If you click the ‘Apply’ button, the time-bar will update
  4. Under Output / Number of frames = type in the number of total ticks + 1 (includes both end frames)
  5. Under Frames, select ‘Active time segment’ which is now a relative number that always starts at zero. Why? Don’t ask.

My recommendation to improve this software?

JUST USE FRAMES and dump the separate ticks, like all the other animation & motion graphics software I am aware of. People should be able to add or subtract frames WITHOUT using another unit of measurement that can be scaled independently. Who is the person who needed this? I’d like to slap their face.


#5

Personally I think that it’s a great feature. Think about it, you have a 300 frame animation of a bunch of objects running for 10 seconds at 30 fps and you want to slowdown a small segment say 10 frames for 40 seconds at 30fps. Normally, you would have have no choice but scale the timeline by 3000 times !! to have enough frames to run the original 10 frames smoothly for 40 seconds at 30fps and end you will end up with a 100,000 frame timeline !! (have fun scrolling up and down the keyframes) … and when you are done scale back to your original frame count for other animations that you might need.
Setting up the frames at rendering time you will choose the segment (still 10 frames) but then you specify the length in secs and fps and it will set the number of actual frames for you and render them.
The cool thing is that the motion is always continuous but is up to you how to divide it in frames. A ten frame animation running for 40 seconds would’t be very “smooth” at 1 frame every 4 secs …
I realize that the example is a bit extreme but real.
Anyway, I really like it (you can slap me in the face if you like). :wink:
I agree that it can be confusing at the beginning. The only thing I would change is to deafult the number of frames to the number of selected ticks which is what you would usually want. Right now it defaults to 100.


(Luc Adriaenssen) #6

Hear hear. Juan, I absolutely do agree. Many thanks for you input.

Not only does the abstract notion “tick” correspond with the academic approach of Bongo (which I believe in strongly), it offers a nice flexibility in managing time. It allows experimenting with the speed of an action, the total length of the movie, creation of slow motions etc…. without having to manipulate the internal structure of the animation defined by its the keyframes.
When I start up an animation project I hardly ever have an idea on the length of the final result nor the precise speed of single actions. Once bussy a view on time and speed arises. Bongo’s Preview gives a fairly good impression of the timing (depending on the complexity of the model and the power of your CPU) but a precise evaluation in my experience can only be made after rendering – I mostly make a draft-render in a shaded Viewport display to appraise timing. Being able to stretch or shrink a scene by one of more seconds (without scaling keyframes) is a great benefit.

I feel a time-management-dialog-tool might be interesting. It would gather all elements in connection with time (timeline and rendering) is a spreadsheet-like environment calculated in seconds and frames. Allowing input in the appropriate fields gives immediate overview of the consequences. The values of the current position of the TimelineSlider can be consulted

To simplify the use, an option to synchronize preview and render (length in seconds) can be included. The default settings would look like this:


(Luc Adriaenssen) #7

Dave,
The ‘Frames’ section of the Bongo Render Animation dialog is more or less made for your multiple sequence project.


You simply leave start en stop tick as they are for the whole animation, select the overall length in seconds or frames and then select the range of frames you want rendered (i.e. 38 … 106) in this section.


#8

Thaks Luc. Fantastic idea to include such great time management tool.
The notion of ticks vs frames is explained too briefly in the help resource under 'Render the Animation’chapter:

Number of frames: Determines the actual number of frames to be output. As ticks do not equate to frames, this value can be anything you like. Changing this value will alter the Length in secs. value.

I feel that this important concept deserves way more space in the help file and possibly a video tutorial explaining more in detail its advantages and how can be used to manage time. I don’t think that everybody is aware of its power.


#9

By the way … does anybody know how to sort the forum thread with the newest post at the top rather than having to scroll all the way down ?


(Luc Adriaenssen) #10

I posted your question on the category Meta which discusses Forum issues.
http://discourse.mcneel.com/t/can-posts-in-a-topic-be-ordered-latest-up/32741


(Luc Adriaenssen) #11

There is a little bit more in the Timeline Ticks paragraph of the Timeline Window Overview:

but I agree it deserves better.

I’ve been toying with a plan for a tutorial on time-management for some time (it’s not the first time the issue arises on the forum). I’ll highlight it in my to-do-list :slight_smile:.


#12

Thanks Luc. A video tutorial would be great !


#13

The problem is that all of the options are at the same level and are not intuitive. These options are only ‘obvious’ if you wrote the code or use the app every day. This is known as the “*curse of knowledge.” For casual users and especially beginners, it’s unnecessarily complex.

For example, let’s say this need to use a range of ticks equal to a different range of frames is helpful for 2% of advanced users. So, why are the options always shown? It’s not helping the other 98% – or vast majority of users.

I suggest a minor revision:
The first option should be ticks = frames. If you select ‘yes’ then all of the other fields are disabled or hidden.
If the ticks = frames = no, then you can have additional options become select-able.

“The Curse of Knowledge: when we are given knowledge, it is impossible to imagine what it’s like to LACK that knowledge.”
― Chip Heath, ‘Made to Stick: Why Some Ideas Survive and Others Die.’


Output options issue
(Luc Adriaenssen) #14

Dave,
Don’t forget the ‘Curse of Knowledge’ also applies to yourself. It’s obvious you are a wizard with Adobe’s Creative Cloud and accustomed to thinking in terms of frames. I assume though that most people (I wouldn’t dare suggest a percentage) will think of seconds (or minutes or hours) when it comes to measuring and communicating time.

But indeed, an option “1 tick = 1 frame” is certainly a meaningful option in a time-management-dialog. Evidently this technique simplifies matters by downsizing the number of input fields to 3 (start and end of the animation and framerate (15, 25 or 30 fps)). This would give something like this (for your morph-project above).

Obviously the images of the TimeManager above (which I edited) are only drafts (in Excel) who need to be styled and formatted properly.
You are right; in the default setting ‘synchronize preview/render ‘ the contents of preview can be hidden since the render settings are identical, hence reducing the number of input boxes.

In the timeline-playback-skips-frames discussion the use of ratio for Timeline speed is argued. The idea is to offer (via radio buttons) 2 alternative ways of defining the relationship between ticks and preview-duration: either by defining the absolute length in seconds (which length will then remain constant) or by defining one of both ratios. In the latter case adding ticks to the timeline would automatically alter the duration in accordance to the ratio.

The current-tick-line is plainly the actual position of the Timeline-slider as any informative bonus.


Output options issue