Creating images with smooth color transitions

Smooth color transitions is a recurring subject of requests that Artoonix developers encounter. We will show here how one can use already existing Artoonix drawing 1.9 tools to create smooth color gradients and create some stunning images in a very simple way. Naturally, Artoonix also lets you animate those to create even more beautiful animations .

We will use the “water lily” example (artoonix .icp project file for your own experimenting can be downloaded, simply follow the link at the bottom of this page). The final result looks like this:

As one can see it is rich in the use of halftones and smooth color transitions. And all this is fairly easy to make by using basic tools: the round and square section brushes, the transformation and deformation tools, as well as Selection area tools.

Creating a background || Creating a flower || Finishing Touches || Downloads || Animation

Creating a background

To start off, let us create the background as shown in the following steps (please, also refer to the picture below):

1. Set the current tool Brush / Free hand painting, and the largest size of the brush – 50 ( it will be easier to operate in the future). Now, in the options panel below, set the “Shape” of the brush to “Rectangular” (“W”) and “Hardness” to Soft (“S”). Choose Blue color in the palette and draw in a new object a short vertical “stroke”, so that it looks similar to (1) in figure below

2. Use Simple Transform (“T”) to stretch it to get something like (2). As you can see, we have a rectangle with a smooth transitions of blue around its center.

3. We will only use the bottom half of the rectangle to get a shift from blue to transparent (not white!). To do this, select the upper half (use “Rectangular Selection area” tool) and remove it (right-click, choose Selection area tools-> Clear area).

4. Stretch the gradient blue object to the desired size.

 

 

 

 

>> Repeat the steps above to a create a similar transparent-to-green object.

5. We can now blend two created objects, using, once again, the Simple Transform tool. The gradient effect is here!

6. Shadow: Create an object with gradient of black, and turn it like shown in (6).

Now, Merge objects.

7. Copy the part that you think looks like your background ( using the Selection area tools-> Copy area), delete all objects and then do the “ Paste from clipboard” into a new object. With a little bit of luck you will get something that looks like (7). This is the background of our image.

 

 

 

 

Creating a flower

Now let’s see how you can create a flower, water lily. Here’s a detailed description of the process:

1. Create an ellipse using a combination of tools Brush / Ellipse and lilac fills with Brush / Fill.

2. Create a new object (Alt + N). Just like when you were creating the background, select the Brush / Free hand painting, but now set the Shape to Rounded (“Q”). Take the maximum size as well – 50. Now select the pink, and click the mouse to get a dot like (2).

3 . Stretch the dot to the desired size using the simple transform tool. Now you can see that the pink grades smoothly from the center to the edges.

4. Combined (1) and (3) is the petal with nice gradient color transition. Merge them into one object.

5. Duplicate the petal object (4) and then use the deformation tool to make something like (5).

Make several petals and combine them into a pretty flower:

Finishing Touches

The next step could be to combine in one frame all the objects – created as described above, and those that were made in a similar fashion: a pair of leaves of the water lily, as well as light spots and shadows.

To conclude, it is very easy to create simple yet very effective color transition effects in Artoonix.

Downloads

Feel free to explore artoonix project with objects described in this tutorial, download it here (zip file, 518kb), unzip and place .icp file in your Artoonix Projects folder.

Animation

And do not forget – not only you can create beautiful picture in artoonix, you can bring them to life too!

 

Smooth Movement animation

Artoonix version 1.7 introduced so-called “frame-tweening”, a tool that makes it exceedingly easy to create movement effects in animation. Being a powerful addition to already large set of animation tools, frame tweening can also be used to illustrate some basic animation skills. This article discusses why some animations look smooth and fluent while other don’t (while seemingly they should have!). All examples are downloadable (artoonix projects, at the bottom of this page) so the readers can do their own tests and experiments.

Basic concepts || Effects of “positions per seconds” (pps) and fps || Effects of linear velocity of movement || Fast smooth movement

Basic concepts

To start off, let us introduce some terms that will be used throughout this article.

• pps – “Positions per second”, also sometimes referred to as “poses per second” (especially in animating a character). This value reflects how many changes object undergoes in the animation sequence per second. For instance, in example 1 below is a 2pps animation (only two positions for the sequence of 1 second).
• fps – “Frames per second” (fps) is the rate at which the consecutive images (frames) are displayed. This is a global property in artoonix and can be adjusted in main projects window “options” “Movie” tab. By default it is set to “16”, which provides the best trade-off of quality vs. filesize (of the exported to video animation). We use in this article 30fps rate unless specified otherwise.
• velocity – the linear speed of movement of the animated object. Typically it is measured in cm/sec, but here for simplicity we will use pixels/sec (as the actual computer animation will have different values of cm/sec velocities for the same resolution of video run on different screens).

Let us work with a very simple animation of a square passing from the top-left corner of the screen to the bottom-right. It doesn’t look like much animation yet, so let us have a look at the way we can improve the situation and test various parameters introduced above.

Effects of “positions per seconds” (pps) and fps

The next example shows the same animation but with 5 frames inserted using standard tweening tool in artoonix. The whole movement is done in 1 second (meaning that there is a 200 millisecond delay in change over of the frame). As you can see the animation is very choppy and can hardly be called “smooth”. Let me remind you that in this case the frame rate is 30fps, and velocity is 275 pixels/sec.

Let us now increase the pps to 30. Once again, simple in artoonix – use frame tweening in the original animation and now set the frame delay to 33milliseconds (to again have the movement completed in 1 second). The result is below.

It is clearly better and rather smooth. However it is not quite perfect just yet. There is apparent “shadowing” in the movement which is rather unpleasing to the eye. Can we improve it by further increasing the pps number? Unfortunately not – the fps is set to the maximum of 30 so whatever frames we would insert would be lost during export. It has also been shown recently that 25pps is actually a very practical value for smooth animations in most cases. So what is going on here? Let us try now the next parameter – movement velocity.

Effects of linear velocity of movement

The animation below is exactly the same as the previous example but the velocity has been halved to 190 pixels/second. This clearly results in much reduced “shadowing” effect.

which can be completely removed by reducing the velocity to 100 pixels/second as shown below:

So, the question that rises whether the 100 pixels/second velocity is a magic number to guarantee smooth animation? The answer is, in general case, “no”, as the actual perception of the movement depends on many factors, such as background elements, their relative movement, complexity of movement of the object itself and many others.. However it does give a good ballpark figure of ensuring smooth motion.

Fast smooth movement

From the text and examples above one could conclude that only slow animation can be smooth. It is so if only the three parameters (pps, fps and velocity) are considered. Another, very important one is the actual perception of movement that is created in human visual cortex (that’s a part of the brain where actual image processing is done on the basis of the “frames” that eyes capture). For instance, consider the animation below. The effect of fast movement is pretty solid, no jerkiness or other detrimental effects are visible.

And yet the sequence is extremely simple – what it is exactly you can see for yourself in attached to this article Artoonix project that you can download at the bottom of this page (the one that is labeled “FAST” ;)).

To conclude, it is very easy to create simple yet very effective animations in Artoonix, especially when used with frame tweening. We have demonstrated here that a number of parameters needs to be considered and applied properly to achieve perception of a smooth animation.

The complete set of artoonix projects that we used in preparing this article can be downloaded here (compressed with winrar, 227kb file).

Start experimenting yourself, and, most importantly, have fun!