@Dr-Sassi Thank you for your quick response Dr. Sassi. Just found some tutorials about Volume Builder I am going to try. In the meantime here is a C4D project. Smile_animation_reveal.c4d

Hello, I would like to achieve a consistently smooth drawing effect with rounded corners during the animation. I attempted to use a Spline Mask to reveal the object, but encountered shape mismatches. Additionally, animating the points of the spline proved challenging as there was no option to apply an easing curve to those keyframes, resulting in a strange-looking animation. I would greatly appreciate it if you could provide some techniques to help me achieve the desired effect, particularly when working with a 3D object that needs to react to bevel edges and geometry.
C4D scene screen recording using Spline Mask :https://drive.google.com/file/d/1_JdnST7KaL5d4xhEnJutuWfGM-F6H61h/view?usp=sharing

Thank you in advance for your assistance.