Dmitriy Zub

kodra
Man having to put the images into a .zip manually is UX horror. They really should've made it work with embedded images and external URLs.

Possibly there's another, proper way that somehow does all those mentioned steps automatically But yeah, using [Image:opdef.?<IMAGE>]would be much more intuitive and expected

P.S. - I've submitted enhancement request.

After some digging...

Houdini markup page example images are stored at this path: C:\Program Files\Side Effects Software\Houdini 20.0.653\houdini\help(ZIP file) so they're not embedded.

Using the absolute path to images also doesn't work: Qt Error: Not allowed to load local resourceeven though using absolute paths in HDA is inappropriate.

Solution:
1. SideFX team, please, update Compare Images Markup documentation [www.sidefx.com] 💛
2. Copy-paste your images inside C:\Program Files\Side Effects Software\Houdini 20.0.653\houdini\help\images.zipZIP file.
2.1. (optional) In ZIP file, create a subfolder like my-mega-custom-folderto store custom images for HDAs.
3. Use your image without opdef.?. Use this: /images/spiderman2.jpg. If using a custom folder: /images/my-mega-custom-folder/spiderman2.jpg
4. Important: close and open Houdini. I believe that this is to compile all files from \houdiniand other folders.
5. Open your help page.

Result:

This is a solved issue. I want to document it for someone who possibly encounters it in the future.

SideFX team, if there's an option to improve the error message, it would be a blessing

Context:
- Substance Painter to Houdini USD workflow
- UDIMs
- Karma render

Error messages:
- libpng error: bad adaptive filter value
- libpng error: IDAT: invalid block type



Writing error message and a picture since it will better be indexed in Google search.

Solution:
- delete exported textures from Substance Painter
- export textures again
- optional: Render menu at the top -> update textures [www.sidefx.com] | Perspective -> Reset Karma XPU (or Shift+P)

I somehow understood that it's related to textures after reading through this and searching occurrences of libpng: https://www.sidefx.com/docs/hdk/png_8h_source.html [www.sidefx.com]

Why it happened (my guess)
Substance Painter exported 1 UDIM tile texture cropped i.e. half of the texture was black and only half of the top part was with texture. And Karma didn't know what to do about it. Although the Painter export message said, "export finished successfully".

All the best