Where is the kategory "Questions "how to" ? automated change of color for a defined area

Hello Everybody,

I’m using some other userforums. Such different things like CAD, RC-Piloting, elctronics and coding. From al these forums I’m familiar that there is at least a sub-section for questions how to do XY. Maybe I have just tomatoes on my eyes but I could not find the “how-to”-Section of this userforum. I would be very thankful if somebody can guide me to where I can ask “how to” questions. @admin: if you think my question is offtopic move it to the relevant category:

my question is: is there any kind of tool that supports coloring a part of the screen continously with a certain color? I mean imagine an empty drinking glas. Now I would like to animate that the drinking-glass is filled with blue water slowly. I define the borders of the section that should do the colorchange. I define the direction (here bottom-up) and speed how fast or slow the colorchange should progress along the defined direction.

best regards


To answer the forum-related question, the intended category for that is “Installing Pencil2D / How to” (#support). Perhaps the double title is a little confusing? I think that category name is still from the old forum, before I joined the project, so personally I’m open to other suggestions there.

As for the tool you’re looking for, I’m relatively sure it does not exist, but I’m also not entirely up-to-date regarding recent developments. Probably one of the others can (and will) shed more light on that.

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@StefanL38 Welcome to the forum and thank you for your interest in Pencil2D. Sorry to hear you found the layout confusing. As J5lx expressed some labels were inherited from the previous iteration but we’re open to changes (in fact I’ll look into it later with the team to see how we can improve this)

As for your second question, I’m not sure I entirely understand the scope of your requirement, however I will mention some general concepts in order to round-up some potential responses to your queries:

  1. Pencil2D is oriented for traditional animation, that means , it is meant to be used to draw everything frame-by-frame. As such there is not automatic way to move or color elements yet, and while it’s possible these can be implemented in the future, such functionality will be limited in scope.
  2. As for having water being poured into a glass, if you want something automatic yet realistic, this enters into the realm of Dynamics and fluid physics, which are way beyond the scope of this program. That said I could recommend other applications that are geared towards this.

For automatic motion of drawings and elements you create, as well as the possibility of changing colors and other attributes between frames (and even having a mask functionality) I’d actually recommend checking out Synfig (https://www.synfig.org) which is a vector based animation software that has motion and shape interpolation along layer effects to change color and other properties over time with less work.

For dynamics simulation you should definitely try Blender (https://www.blender.org), while this one is a 3D application suite, it has a lot of elements that can help with CAD for Engineering and for creative purposes. Recently they added a new fluid simulation engine that is industry standard and you can take these simulations and render them to appear 2D, as if drawn by hand (via freestyle rendering, or grease pencil rotoscoping) though this too requires some studying.

Blender too works with vectors (meshes for 3D, bezier splines for grease pencil) and for 3D has automated interpolation between keyframes (containers that save the state of the object attributes over time)

To make a glass being filled by water in Pencil2D you’d have to draw the empty glass in one layer. And create another layer to draw the water being poured into it, frame by frame, so each state of the water, over time will have to be drawn by you, and in that sense the water will be as realistic as your ability to both understand and represent how water physically drops into a recipient.

I hope my answer is clear enough and help guide you to using a proper application for your purposes. either way you’re more than welcome to share your work in the future, even if it’s not made with Pencil2D.