why init_sigma is 2.5?

[crj1998]

Theinit_sigma in the inference script is 2.5

SIM/README.md

Lines 34 to 42 in 6535530

	```bash
	python inference.py \
	--dit_model_path "/path/to/our_model" \
	--text_enc_path /path/to/PixArt-alpha/t5-v1_1-xxl \
	--vae_path /path/to/PixArt-alpha/sd-vae-ft-ema \
	--prompt "a colorful painting of a beautiful landscape" \
	--output_dir out-0 \
	--batch 4 --seed 112 --dtype bf16 --device cuda --init_sigma 2.5
	```

I try to change to 1.0 which is same as the pixart default, but the result is bad. I am wandering why use 2.5 as init_sigma?

[fetchniches]

We set init_sigma=2.5, following the convention established in prior works such as DI and SiD. Since this value remains fixed during training, modifying it may lead to unexpected behavior.