Does "nicely rendered the drawings" mean "made the drawings much better"?

Context:
Many others have assisted in the birthing process of this
book: Judy Hutchinson faithfully transcribed my dictated drafts,
Michael Hagelberg nicely rendered the drawings from my
sketches, and important critiques of early drafts of chapters were
provided by Drs. Frank Albrecht, Ewan Birney, Eric Lander, and
Bill Phillips. As my agent, Gail Ross has provided the practical
experience that this novice writer sorely needed, and Bruce
Nichols has been a perfect editor!aprovidig encouragement for
the possibility of this book before I was convinced it could hap-
pen, expressing confidence over the rough spots, and setting
high standards for clarity and accessibility.