Great work! Looks quite accurate.
It's missing the minor details if one hasn't noticed, like Canard and control surface actuators and such. It's length is 20.3m and wingspan 12.7m so its on the slightly smidge lower estimate. The three-view drawing is well, just a bunch of random images I slapped together. There aren't many good orthographic views of the J-20.Great work! Looks quite accurate.
So you said the solid body volume is 64 m³ ? May I ask which three-view drawing and dimensions you used?