ϵunc = fdiffusion(xt; t),
ϵpos = fdiffusion(xt; y, t) − ϵunc,
ϵpredict = ϵunc + wguidanceϵpos,

where ϵunc is the NSF of the unconditional data distribution,
and ϵpos is the residual NSF conditioned on the text embed-
ding y. ϵpredict is based on a classifier-free guidance formu-
lation [8], indicating the direction for updating the image to
match the text description y, and wguidance denotes the guid-
ance weight.

(2)

(3)

3
Instant3D