Projet image 2017 : Tools for interaction with Animated Paint

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Abstract

Nowadays graphical engines aim to be more powerful, complex, expressive and realistic. As an advance improvement step towards thees goals in current work it is proposed to animate the paint behaviour. Subjecting to a possibility that the novel animated paint can have the desirable of complexity and realism, it will be needed to find a efficient way of interaction with it. The more sophisticated model would be, the more sensors, controls, settings the user will have to care about. In current work we proposed the manipulation strategies for some of possible characteristic of animated paint such as intensity, direction and history tracking. We also studied general user impression regarding such kind of design workspaces, trying to find out the most prospective applicational field and target group of users.


Introduction

Motivation

Throughout the history of the fine arts painters all over the world came to the point, that for human eye the best esthetics is in natural-based forms. Of course it does not mean that all the painters should come back to Renaissance and follow only natural shapes to create a masterpiece. But it means that it is a powerful instrument of manipulation with humans perceptions abilities. So what stops us to bring this principal to digital tools?

We can admit that nowadays graphical engines made a huge progress and provided a powerful instrumentation for artists. But still digital editors are not always able to give a good feeling as working with analog tools. For example, there are very interesting techniques with alcohol ink and watercolour, which are still very challenging to reproduce using graphical software: https://www.youtube.com/watch?v=ZGI9y9N3jlg

Intro000.jpg

That is why digital artists are often using analog materials to achieve some unique effects, which implies a lot of issues majorly connected with paint unpredictable behaviour. Moreover, after that a painter needs to scan the piece to work with it further, which means loss of quality, the result is just a 2D picture which is not flexible for manipulating (no layers, no shapes, no changing history).

Observation of existing solutions

Continuing the criticism related to existing design tools I should point the next shortcomings:

1. Most of the tools do not model the dynamic of paint behaviour itself, they show just final result (brushes in Photoshop).

2. The tools (Adobe Aftereffects) which allow to model the paint behaviour are taking the principle of after processing, so that you can not control your virtual paint in a real time.

3. More sophisticated materials are not represented in popular engines such as products of Adobe and Corel.

New engine concept

I would like to propose a tool for designers which main purpose will be to provide a feeling of work with analog materials such as alcohol ink, watercolour, acrylic. Apart of it I would like to propose a quite new principle of interaction with artistic software, which will be oriented not only to the result of work itself, but could be used for animating/filming of painting process.

The main features of this engine will be:

1. The program will show all the process of paint spreading: starting from a drop on a canvas finishing with a final state “when the canvas is dry”

2. A designer will be able to stop the paint spread in any moment, track it back or forward, change the speed of process

3. The tool will allow to record a video of painting process, so that the process of painting creation could be done as a performance.

4. The tool will allow to imitate change of behaviour of paint spreading depending on angle of canvas, external forces (as wind), collision with other paint.

Application domain

Due to feedback of target group of users I would like to specify at least several application fields of this engine:

1. Digital painting. Creation of advanced artistic effects.

2. Feature for artists bloggers who record the video of painting process.

3. VJing, interactive / life-generated decorations, performance art. As this tool will allow generate animations based on painting process itself.

4. Marketing. Let us take an example when a new model of tablets appears on market. A manufacturer needs somehow to gain a new interest of potential customers and motivate them to select particularly this model. In case a company will distribute this tool, outlining that the target group of users are artists, it will rise the interest to new brand as well.

5. Animation effects for video.

6. Engine for fast banners creation.

7. Analog-like textures creating. In some cases adding fume/sparkles/fire/paint flows either does not look artistic enough either tend to take much time.

Focus of research. Problem formalisation

First of all, it should be noted, that in current work I am trying to propose an interation approach for a system which supposed to be complex: it should animate the behaviour of paint flows, fume, sparkles, fractals... The variations, how exactly the animated paint should be represented should be as much as to cover the great variety of user needs in this specific domain.

But suppose, we have this sophisticated tool, how user will control it? And in fact we are facing with a classic trade-off in the field of computer graphics and animation: complexity vs. controllability. That is why the main goal of this work is to make the first steps to find the balance between thees two features.

Info00.jpg

In current project we would like to investigate the strategy of manipulation with animated paint and propose suitable tools for it. Obviously, we are dealing with a complex system consisting from thousands of particles. It makes no cense to specify the motion for each of them, so we need to propose more easy way. It was decided to control the intensity with pressure, direction and state of paint with widgets.

Info01.jpg

In particular, we will focus on, how native the controls for direction and history are for user. Additionally, we would like to find out the general impression about usage of the novel tools, presented in prototype.


Why studding of the controls for manipulation with moving paint is important? To change the behaviour of paint an artist needs to stop painting and change the pre-sets of drawing application. The problem becomes even more explicit, if we imagine that an artist needs to do it in real time with minimal interruptions from the painting process. In other words we are observing context switch problem.

The process of context switch can bring overall degradation in task performance, so that it is important to find how to make it less painful for user.


The New Engine

Prototype

We designed the system in order to appear to the user as an application for a tangible interface - graphical tablet. The challenge point was that in fact we want to study the interaction with something which not yet exists yet. It was observed that it is difficult for user to give a clear picture regarding animated paint just from description, as this is something that user needs to try and to feel. To give an artist a better impression about "alive" paint for the simulation we used a particle system with some physics-based behaviour assigned to particles. To give a user a better impression of what kind of product we hope to implement in future and help the user to detect the possible problematic spots of interaction with it, we designed 3 versions of prototypes.


1) Prototype 001 https://youtu.be/8p3Obt4pDgE For comparison of direction tools.

Pr001.jpg

2) Prototype 002 https://youtu.be/w1OIqNCqiDA For evaluation of history and direction tools.

Pr002.jpg


3) Prototype 003 https://youtu.be/0HcEHs7Jd9E For evaluation of general impression of usage of novel tool. Evaluation of intensity control with amount of preasure

Pr003.jpg

Implementation

To evaluate the techniques for direction and history controls and to find out the general impression about usage of the novel tools I created 3 versions of prototype. It is known that liquid phisics behaviour similation is resourse demanding and complicated task, so , technically, it was not always possible to find a perfect compromise in controllability of particle system, complexity of implementation, efficiency of performance. On the other hand, different sets of prototype allowed user to focus better on particular problem or task.

Technical overview of prototypes proposed:

1) Prototype 001. Implemented on C++ using Qt libraries. Performs a simple animation which could be interacted using propose controls.

2) Prototype 002 Implemented on C++ and QML using Qt libraries. Uses OpenGL particle system and render. Provides better visual impression though has less controlability due to technical limits of Declarative System.

3) Prototype 003. Implemented on Unity. Based on Unity particle system. Compromise between controlability of the system and visual effects.

Conducting experiments

Experiment Protocol

Proto06.jpg
  1. 8 participants were asked to test 3 versions of prototype. Among participants : three are professional artists, three doing art in free time, two do not have big interest to do painting or fine arts by themselves.
  2. Participant is informed about the goal of the system and about its functioning.
  3. Participant can play with our application and to get used to the interface for 2 minutes.
  4. A brief interview with the participant to know there background and impression of tool.
  5. Ask the participant to fill the questionnaire Google Form to provide additional feedback for the application.
  6. For testing process we used graphical tablet (Wacom) and a touchpad.

Scenarios

It was proposed two test scenarios to a user:

1. You need to generate the background with splashes for some particular image. Add stars to winter landscape image.

2. You would like to record a video for your blog about the process of painting. The process of your work should demonstrate your professionalism and give good impression of working with “alive” paint.

Assuming thees situations we asked a suer to add some effects on image using different engines and evaluate the prototypes.

Evaluation

We made a small discussion with users, letting them give answers in free form. However, we also used the evaluation proposed in IBM Computer Usability Satisfaction Questionnaires[2]. Full set of questions could be found here: https://docs.google.com/forms/d/1eeWJHPO4X5b1t1mdWsf97HKR1PP2CD2ahnRWF2pfCbU/edit?usp=sharing .

Provided set of questions is splitted into sections:

Section 1. Problem background

Figure out the background of user. Comparison of new tool with known ones (Photoshop, After effects, Corel Painter) in terms of proposed scenario.

1. You need to generate the background with splashes for some particular image. Add stars to winter landscape image, for example.

  • Briefly explain, how would you do this task and what software you use?
  • How much time it will take?

2. You would like to record a video for your blog about the process of painting. The process of your work should demonstrate your professionalism and give good impression of working with “alive” paint.

  • what factors/situations you would like not to show to viewer?
  • How would you do the painting process interesting for viewer?


Section 2. RadioDialog vs Slider

Prototype 001. We compared the RadioDialog and Slider for specifying of direction. We also evaluated if the general idea how to control the direction is clear and comfortable for user. We found an average in even and odd questions responses separately, which corresponded to votes for RadioDial and Slider tool.

Direction control evaluation (prototype ver. 001)

1. It was easy to learn to use this system.

  • With radioDialog;
  • With slider;

2. I believe I could become productive quickly using this system.

  • With radioDialog;
  • With slider;

3. It was easy to find the information I needed.

  • With radioDialog;
  • With slider;

4. It was easy to specify the direction of spread which I need

  • With radioDialog;
  • With slider;

5. It was easy to find the state of paint (with direction tool) which I need

  • With radioDialog;
  • With slider;

6. In case the result I obtain (in terms of direction) does not satisfy me, I know how should I improve it next time.

  • With radioDialog;
  • With slider;

7. I consider the direction tool easy to use.

  • With radioDialog;
  • With slider;

8. I consider the direction tool precise.

  • With radioDialog;
  • With slider;


Section 3. Direction of motion control.

Prototype 001. Direction control evaluation. General impression. We asked a user questions regarding how comfortable for them to control the directions in the way we proposed.

Quest001.jpg


Section 4. History control.

Prototype 002. We asked user to focus on evaluation of history and direction tools.

Quest03.jpg


Section 5. General impression.

Prototype 003. Evaluation of general impression of usage of novel tool. We also tried to figure out if the idea with animated paint is more appropriate for non professional users.

  1. In case you do not know how result should look like are you satisfied with the time spent on work?
  2. In case you do not know how result should look like are you satisfied with the result of work?
  3. In case you do not know how result should look like did you get some interesting ideas during work?
  4. Your suggestions.

For all tests we counted the average of responses in percentage.

Analysis of the results

Section 1. Problem background

Here we reviewed how user will solve the given task with existing tools and how effective is it in comparison with novel tool.

We have found out that even adding of quite simple effects to picture normally takes around 10 min for professional artists and up to 25 min for the ones who are doing it on free time only. From this point, everybody gave a responce that having a good preset of effects with our new tool it will be possible to accomplish the task in several minutes. If we consider more complicated tasks, the time difference will be even more explicit.

Based on all 3 prototypes all the users ( of different background in digital painting ) admitted that in case of good implementation the proposed engine can be times faster solution for this case and reduce the time of work to several minutes.

Artists gave an opinion that this tool will give a good feeling of painting process thanks to animated effects:

  1. "If the painting process would be more realistic, or well-animated, it would be interesting for user."

Section 2. RadioDialog vs Slider

In this part user evaluated the prototype 001. We compared the RadioDialog and Slider for specifying of direction. We also evaluated if the general idea how to control the direction is clear and comfortable for user.

Slider and RadioDialog were approved by user (more that 50% of possible score). But RadioDialog gave much better impression to user ( 92,2% ) in comparison with Slider ( 62,2% )

  • Among users voted for "RadioDialog" the explanations were:
  1. "It is more intuitive, easy corresponds to 'arrow' angle."
  2. "It is also fine to use Slider, just a bit more time is needed to get used to."
  • Other direction control proposals:
  1. "I would like to use the controls of tablet with one hand and paint with other, so that not to switch my attention."
  2. "On right button of stylus hold allow to draw an arrow right on canvas. On button release - update the direction."

Section 3. Direction control

Dedicated to direction control evaluation based on Prototype 001. We asked a user questions regarding how comfortable for them to control the directions using the system we proposed in general. Focused on help information.

Overall, users were satisfied with the support information and the proposed approach to manipulate the paint. In average the evaluation gave 94%.

  • Remarks from users which were not fully satisfied with arrow position:
  1. "It is not always suitable/possible to find out precisely the angle you need using the arrow from aside of canvas. It could be more efficient to draw an arrow on canvas directly as a preprocessing step"
  2. "If I would like more complicated direction than just a line, how can I do it?"
  3. "If I work with a part of picture, which is remote from control panel, it is hard to see what is the angle. It would be better if arrow will appear somewhere near working area"
  • * Remarks from users which were not fully satisfied with arrow position:

"It is not a precise plot. It is a hand painting! It does not need to be that precise."

Section 4. History control.

Based on Prototype 002 were e asked user to focus on evaluation of history and direction tools.

Generally we received positive feedback regarding the idea of history and the history control proposed to manipulate the paint. In average user satisfaction was evaluated as 87%.

  • Feedback, which came from amateur painters:
  1. "History control is what definitely will help the artist. In Most times I have a good line/effect and do not want to redo it from zero for a slight modification. "History" will help to make it even better by selecting the best 'state' of paint."
  • Feedback, which came from professional painters:
  1. "I most likely will not use "History" control, as I know which result I want to see. But it is good for improvisation or searching the idea" "
  • Feedback, which came from others users:
  1. "Add history to all layers, not to just the last one"

Section 5. General impression.

With Prototype 003 tried to figure out if the idea with animated paint is actually demanded? Is it easy to work with

Topic actuality. General impression.

In average user satisfaction was evaluated as 78%.

  • We have also obtained interesting general remarks from professional artists regarding the idea of spreading paint:
  1. "It is not always demanded, as in most cases you know what you want to see. In case I would like to improvise, it is a demanded approach".
  2. "This is a very interested idea including the common tendency of increase of interest to animation"
  3. "I see this idea rather for animation creation rather than for drawing"
  4. "I would use this kind of tool for creation of effects on picture."
  5. "I would show how I am using this tool, when will record video of my speed painting to attract more viewers."
  6. "It is a known feature when it's allowed to control the amount of paint by pressure. I think it is also logical to apply for case with animated paint"
  7. "Looks like it can be an advanced tool, so for new user learning time would be required. Make sure you can motivate the artist to master it."
  • Non-professional artists were generally satisfied with the result they could obtain and with time spent on a task.
  1. "Some times if I do not know which final result I expect , it is useful to see different options."
  2. "It gives better feeling of a process of drawing. It is relaxing"
  3. "Normally, the video and image post processing tools are quiet complicated. It is useful to have a program which can provide the animated effects in real time and create and save as videos or banners"
  4. "Randomnes I can see in paint behaviour is something new and attractive, but I would like to control the amount of it."
  • Part of users without artistic background did not see any interest behind the novel tool. Other users were generally impressed with the idea of the tool as , probably, were not demanding to the quality and professionalism of the result.

Positive feedback from users without artistic background :

  1. "I would use this tool to add some effects on pictures, as I have no idea how to do it with at least that quality in professional programs."
  2. "Feels good that I can do something nice without having any clue how to draw."
  3. "Mostly for fun. Very relaxing"

Conclusion.

In current work we proposed and evaluated several ideas how to control a complex system in easy and native way. Proposed idea to control of direction and history of animated paint received positive evaluation from the side of users. It was supposed that the implemented board of tools would be easy and effective for changing of the parameters of paint motion. Still, the evaluation showed that the context switch, which user needs to perform to change the properties of paint behaviour, still interrupts the work process. It means that the controls, proposed in current project, need further improvement. As a way to increase the productivity we need to think of how to engage both hands of a user in painting process.

Generally, we received an impression that for now professional artists do not see the proposed engine as effective enough for accomplishing general work tasks. Main reason was that the system still behaves unpredictably for them. It is more likely to be a tool for fun or improvisation. At the same time some users resumed that as any new tool, it requires some time to master it. On the other hand, this engine could be very useful for cases when user does not know which result he wants and can get, to receive some inspiration in process of work.

Future Work

In the next versions we would like to add more tools to control more physical properties of paint behaviour such as speed, fluidity, noise . We also would like to propose other interaction strategies, more focused on graphical tablet design - assign control buttons for direction changing, or history tracking.

Support information which was provided in software was helpful and intuitive for user. However to obtain more precise controllability it is needed to show information closer to focus area. On the other hand it is not obvious solution as help information might overlap with work context.

Taking into account the feedback from users, we will try to develop the idea of paint animation in real time for "Life Decorations" or VJ-ing. We also will try to enhance it in fiend of video post processing and animation effects creation.

Attachments

[1] Evaluation questions: https://docs.google.com/forms/d/1eeWJHPO4X5b1t1mdWsf97HKR1PP2CD2ahnRWF2pfCbU/edit?usp=sharing

[2] Prototype 001 https://youtu.be/8p3Obt4pDgE

[3] Prototype 002 https://youtu.be/w1OIqNCqiDA

[4] Prototype 003 https://youtu.be/0HcEHs7Jd9E

[5] Evaluation video recording: https://drive.google.com/open?id=0B4NfUY-qnTL8NzJqcUNCWUZzSG8

References

[1] http://www.slideshare.net/Abd0/multimodal-interaction-an-introduction

[2] IBM Computer Usability Satisfaction Questionnaires: Psychometric Evaluation and Instructions for Use. Technical Report 54.786, James R. Lewis, Human Factors Group, Boca Raton, FL

[3] Lecture notes: http://mosig.imag.fr/ClassNotes/UIS-AHCI

[4] The Startup Owner's Manual, 2012, Steve Blank, Bob Dorf