A computer implemented method of composing an animation scene in a computer-generated animation, the method comprising: receiving a user input requesting to perform an operation on at least one computer-generated asset in the animation scene; determining, based on the user input, a type of operation and at least one attribute associated with the at least one computer-generated asset in the animation scene; in accordance with the determination of the type of operation and the at least one attribute: processing representations of one or more instances of the at least one computer-generated asset; projecting the processed representations of the one or more instances of the at least one computer-generated asset onto the animation scene to perform the operation; and generating metadata associated with the representations of the one or more instances of the at least one computer-generated asset, wherein the metadata enables re-projecting of the processed representations of the one or more instances of the at least one computer-generated asset irrespective of the one or more instances being constrained in place; wherein receiving the user input comprises receiving one or more paint strokes with respect to the animation scene, the one or more paint strokes being associated with a radius and indicating a curve extending across at least part of the animation scene; wherein processing representations of one or more instances of the at least one computer-generated asset comprises manipulating representations of the one or more instances of the at least one computer-generated asset in accordance with at least one attribute; characterized in that manipulating representations of the one or more instances of the at least one computer-generated asset comprises generating a representation of an attraction sphere having said radius; and wherein projecting the processed representations of the one or more instances of the at least one computer-generated asset onto the animation scene comprises disposing the attraction sphere in the animation scene based on the representation of the attraction sphere, the attraction sphere enabling an animation of attracting one or more instances of the at least one computer-generated asset positioned within said radius of the attraction sphere, wherein in a dynamic simulation of an animation, the one or more instances of the at least one computer-generated asset positioned within said radius of the attraction sphere move toward the attracting sphere's position. receiving a user input requesting to perform an operation on at least one computer-generated asset in the animation scene; determining, based on the user input, a type of operation and at least one attribute associated with the at least one computer-generated asset in the animation scene; in accordance with the determination of the type of operation and the at least one attribute: processing representations of one or more instances of the at least one computer-generated asset; projecting the processed representations of the one or more instances of the at least one computer-generated asset onto the animation scene to perform the operation; and processing representations of one or more instances of the at least one computer-generated asset; projecting the processed representations of the one or more instances of the at least one computer-generated asset onto the animation scene to perform the operation; and generating metadata associated with the representations of the one or more instances of the at least one computer-generated asset, wherein the metadata enables re-projecting of the processed representations of the one or more instances of the at least one computer-generated asset irrespective of the one or more instances being constrained in place; wherein receiving the user input comprises receiving one or more paint strokes with respect to the animation scene, the one or more paint strokes being associated with a radius and indicating a curve extending across at least part of the animation scene; wherein processing representations of one or more instances of the at least one computer-generated asset comprises manipulating representations of the one or more instances of the at least one computer-generated asset in accordance with at least one attribute; characterized in that manipulating representations of the one or more instances of the at least one computer-generated asset comprises generating a representation of an attraction sphere having said radius; and wherein projecting the processed representations of the one or more instances of the at least one computer-generated asset onto the animation scene comprises disposing the attraction sphere in the animation scene based on the representation of the attraction sphere, the attraction sphere enabling an animation of attracting one or more instances of the at least one computer-generated asset positioned within said radius of the attraction sphere, wherein in a dynamic simulation of an animation, the one or more instances of the at least one computer-generated asset positioned within said radius of the attraction sphere move toward the attracting sphere's position.