Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fixed handling of PLY with vertex colors as uchar #1441

Open
wants to merge 5 commits into
base: main
Choose a base branch
from

Conversation

eguendelman
Copy link

When a PLY model has vertex colors, they're typically saved as uchar rather than float properties.
For example, exporting a mesh with vertex colors from Blender will write it with uchar red, green, blue, and alpha properties.

Currently, Yocto is reading colors by casting to float without dividing uchar by 255. So the colors come out wrong.

This patch changes the logic to ensure that when colors are read, it will normalize any integral type to a floating point value. I didn't really find anything in PLY spec that defines the "right" way to normalize the various integral types, so this is just a best guess (that happens to work well for uint8). I can try to simplify this patch if we don't want to do general normalization and just handle uint8.

I created a PLY in Blender to test this, with a sample scene (materials5).

./ytrace --scene ../tests/materials5/materials5.json --samples 512 --resolution 640

This is what the render looks like before the patch:
image

And this is after:
image

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

1 participant