Texture2D 2022.2 bug

[JunkBeat]

1. There are bugs related to reading/writing Texture2D in Unity 2022.2. To fix this I changed the code as follows and it worked:

if version >= (2022, 2, 0):  # 2022.2.0f1 and up
            self.m_IgnoreMipmapLimit = reader.read_boolean()
            reader.align_stream()
            self.m_MipmapLimitGroupName = reader.read_aligned_string()
            reader.align_stream()

. . .

if version >= (2022, 2, 0):  # 2022.2.0f1 and up
            writer.write_boolean(self.m_IgnoreMipmapLimit)
            writer.align_stream()
            writer.write_aligned_string(self.m_MipmapLimitGroupName)
            writer.align_stream()

Example file: https://drive.google.com/file/d/1TyA0H9myZyvk46MYVAVDW_aiu-Cm2miQ/view?usp=sharing

2. I also encountered problems with poor compression in dxt1/dxt5. The visual artifacts appear on some textures. You can see it visually here (I used the same libraries as UnityPy): https://drive.google.com/file/d/1MZTIq6J_WSYR2IlZELi0rexfxKDO-WCZ/view?usp=sharing

[K0lb3]

You're right, there has to be an align_stream call after reading the m_IgnoreMipmapLimit value. The second align stream isn't necessary through, as read_aligned_string already calls align_stream.

The visual artifacts are caused by the c-library that is used for compression wolfpld/etcpak. As said library doesn't have quality settings, there isn't really anything that can be done about the visual artifacts, besides using a different library for compression, or simply enforcing rgba8 as texture format, which increases the asset size by 4x of the texture size, but should work for all normal material textures.

[K0lb3]

You can try using K0lb3/ispc_texcomp_py which I never came around to make a good build workflow for.

[JunkBeat]

You can try using K0lb3/ispc_texcomp_py which I never came around to make a good build workflow for.

Okay, thanks for the advice, I'll try it.

[JunkBeat]

What am I doing wrong? I'm trying to compress a 512x512 rgba image, but I get an error:

RGBASurface_new
RGBASurface_init
Traceback (most recent call last):
  File "dxt_bad_compression\pycompression_test.py", line 22, in <module>
    surface = ispc_texcomp_py.RGBASurface(raw, img.width, img.height, stride)
TypeError: The stride value is too big!
It has to be the size of a single row in bytes. (e.g. for RGBA -> 4 * width)

Here's my code:

import texture2ddecoder
import ispc_texcomp_py
from PIL import Image

img = Image.open("img_2.png")
raw = img.tobytes("raw", "RGBA")

# compress
stride = img.width * 4
surface = ispc_texcomp_py.RGBASurface(raw, img.width, img.height, stride)
data: bytes = ispc_texcomp_py.CompressBlocksBC3(surface)

# decompress
dimg = Image.frombytes("RGBA", img.size, texture2ddecoder.decode_bc3(data, img.width, img.height), "raw", "BGRA")
dimg.show()

However, this error does not occur if I specify a number one less, that is, 2047, and here is the result after decompression:

UPD. I looked at the code of your module and, out of curiosity, set the stride to 0, and it seems that now everything worked perfectly!

[K0lb3]

UPD. I looked at the code of your module and, out of curiosity, set the stride to 0, and it seems that now everything worked perfectly!

Great to hear. It's a bit weird that stride 0 worked, but as long as it works.

• stride == 0 => stride = byte count / height as the input should be rgba
• byte count = width * height * 4
• stride = (width * height * 4) / height = width * 4

[JunkBeat]

It's a bit weird that stride 0 worked, but as long as it works.

Yeah, I was surprised too, but when I did the calculations I was convinced that both options (set to 0 or multiply the width by 4) would lead to the correct result, even if the width differs from the height:

#Case 1. Height > Width
len = 698368
width = 341
height = 512

stride = width * 4 #1364
# if stride set to 0:
stride = len / height #1364

if (stride * height > len): #1364 * 512 == 698368
    print("Error")

#Case 2. Height < Width
len = 33554432
width = 4096
height = 2048

stride = width * 4 #16384
# if stride set to 0:
stride = len / height #16384

if (stride * height > len): #16384 * 2048 == 33554432
    print("Error")

You have an incorrect condition in this line: if (self->surf.stride * self->surf.height >= view.len) Instead of >= there should be >

UPD. However, yesterday I came across an rgba texture 490x490, the module could not compress it correctly until I enlarged it to 512x512. Is there a way to fix this without having to change the texture size? It seems that the dimensions must be multiples of the power of 2?