Like Marian sais in the peek of the week:
One of the enhancements that sets Riftrunner apart from Divinity 1 is the 3D character system. The characters in Divinity 1 where done in 2D, which had the advantage that the minimum specs were low and that as an artist, you had full control over the render quality.
Unfortunately, it also had the disadvantage that we needed a tremendous amount of data to store it all. If I recall correctly, we needed 1.3 CDs alone for the hero animations in all their variations. The six heroes in Divinity contained together over 900,000 frames of animation, and the dragon you meet at the end of the game contained over 100 MB in uncompressed data. As a result, we animators had to keep the frame count relatively low, and because of that, the quality of the animations was compromised.
And making 2D animations do take a lot of time in comparison to animations with 3D characters. With 2D characters you have to draw all the animations piece by piece, and for each direction. With 3D characters you "only" have to make the animations with the use of skeleton animation.
