I have find some think good today, and drawing new picture with background when I study a tut in cgarena,
You can see difference in this pictures
Left : Render with low Image Precision, GI : 100k
Right: Render with Medium Image Precision, GI : 200k
thank Cgarena and Threed1, Mr namicg,
ð khong nen check vao Exclude GI caculator
ð Cach tot nhất khi ren không được là : xóa cái plane background và vẽ lại cái khác.