Generating hard object shadows for general shadow receivers within digital images utilizing height maps

A non-transitory computer-readable medium storing executable instructions, which when executed by a processing device, cause the processing device to perform operations comprising:

• determining an object height map comprising pixel heights for pixels of a digital object portrayed in a digital image;
• determining a background height map comprising additional pixel heights for pixels of a background portrayed in the digital image;
• and
• modifying the digital image to include an object shadow for the digital object using the object height map and the background height map.

A system comprising:

• one or more memory components;
• and
• one or more processing devices coupled to the one or more memory components, the one or more processing devices to perform operations comprising:
• receiving a digital image portraying a digital object against a non-planar background;
• generating, utilizing a height prediction neural network, an object height map comprising pixel heights for pixels of a digital object;
• generating, utilizing the height prediction neural network, a background height map comprising additional pixel heights for pixels of the non-planar background;
• determining, utilizing the object height map and the background height map, ground points for the pixels of the digital object and the pixels of the non-planar background, a ground point for a pixel corresponding to a projection of the pixel onto a ground surface of the digital image;
• and
• generating, across the non-planar background within the digital image, an object shadow for the digital object utilizing the ground points.