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matroid

Re:Show HN: Move Lights in a Photograph in 3D on Wednesday April 22, 2026 @01:45PM (#47866842)
I guess it would be a good experiment these days, to see how Nano Banana or OpenAI's latest image to image models will be at transferring lighting while preserving the original style domain, like you suggest.

Thanks for the thoughts :)

Re:Show HN: Move Lights in a Photograph in 3D on Wednesday April 22, 2026 @11:14AM (#47864798)
That's a good question!

We made the training data for this using a physically based renderer (i.e, Cycles in Blender).

For non-photorealistic art, there are way too many ways in which artists communicate lighting (even in sketch, which is different from pixel-art / video game, there are at least a couple of ways (a) solid shading (b) hatching).

I'm not sure how to extend our methodology (synthetic data in 3D modeling software + train model) to these settings.

Ooh, I didn't know about Myst-style games. I'll definitely check them out!

Hello, I have this project where you can move lights in 3D inside a photograph.

This is the project page and has some cool demos (atleast I think!). Do check them out and let me know what you all think!

Re:Simple 3D Packing on Friday January 02, 2026 @12:38AM (#46461770)
Thanks. I'll link it in the first line in the README. I think the interlocking-free part can pack cups like you suggest. They propose a flood fill algorithm which computes all the reachable places for the voxelized shape. It doesn't put assumptions on convexity. I think it would be a great example to try it out on though.
Re:Simple 3D Packing on Saturday December 27, 2025 @03:21AM (#46400159)
A while back, I implemented a paper that had showed up on HN for a course project (Dense, Interlocking-Free and Scalable Spectral Packing of Generic 3D Objects).

Over the holidays, I cleaned up the implementation (with the help of Claude Code, although this is not an advertisement for it) and released it on GitHub.

If anyone needs fast 3D packing in python, do give this a shot. Hopefully I have attributed all the code/ideas I have used from elsewhere properly (if not, please feel free to let me know).

Re:FaceLift [ICCV 2025] on Wednesday October 22, 2025 @04:04PM (#45674431)
Hey everyone, I wanted to share my friend's work on Single Portrait Photograph to 3D Head Model. He has a Huggingface demo that you can play with!
Re:Detecting Sign Language in News Videos on Friday August 16, 2024 @12:47PM (#41268052)
Thanks Zie for the message. I'm sorry to hear about your "interpreter" encounter :(

I do think these problems are much, much worse for ISL as you rightly noted.

I think I should have been careful when I said "solve" in my post. But that really came from a place of optimism/excitement.

Re:Detecting Sign Language in News Videos on Thursday August 15, 2024 @06:13PM (#41261023)
Also, in India, many hearing-impaired people know only ISL.
Re:Detecting Sign Language in News Videos on Thursday August 15, 2024 @05:49PM (#41260748)
That is correct. We want to translate between English and ISL. English, because it is by and large the language of the Web and I think we should try to connect ISL to it rather than Indian Languages.

From my understanding, they are quite dissimilar. A person who knows ISL will not understand ASL, for example.

Re:Detecting Sign Language in News Videos on Thursday August 15, 2024 @05:46PM (#41260720)
Thanks for the feedback. You raise great points and this was the reason why we wrote this post, so that we can hear from people where the actual problem lies.

On a related note, this sort of explains why our model is struggling to fit on 500 hours of our current dataset (even on the training set). Even so, the current state of automatic translation for Indian Sign Language is that, in-the-wild, even individual words cannot be detected very well. We hope that what we are building might at least improve the state-of-the-art there.

> It's more of a bad and broken transliteration that if you struggle to think about you can parse out and understand.

Can you elaborate a bit more on this. Do you think if we make a system for bad/broken transliteration and funnel it through ChatGPT, it might give meaningful results? That is ChatGPT might be able to correct for errors as it is a strong language model.

Hello everyone, we are trying to make a large dataset for Sign Language translation, inspired by BSL-1K [1]. As part of cleaning our collected videos, we use a nice technique for aggregating heuristic labels [2]. We thought it was interesting enough to share with people on here.

[1] https://www.robots.ox.ac.uk/~vgg/research/bsl1k/

[2] https://github.com/snorkel-team/snorkel

I have never seen 1x H100 available on Lambda Labs. Don't know why though.
Re:Segmenting Comic Books Using SAM (Segment-Anything) on Tuesday February 27, 2024 @12:27PM (#39526760)
This is such a good resource! Thank you!
Re:Segmenting Comic Books Using SAM (Segment-Anything) on Monday February 26, 2024 @11:55PM (#39520324)
All that sounds definitely a lot of fun. I was also working on colorization with SD ControlNet recently (https://vrroom.github.io/blog/2024/02/16/interactive-colorin...).
Re:Segmenting Comic Books Using SAM (Segment-Anything) on Monday February 26, 2024 @11:32PM (#39520166)
Wow! Thanks for sharing this.
Re:Segmenting Comic Books Using SAM (Segment-Anything) on Monday February 26, 2024 @11:06PM (#39520038)
The author here. I would just like to say that this project is definitely work-in-progress and the AI elements often fail miserably.

As amazing as recent AI progress has been, we do overrate it a lot (I'm including myself in that).

Re:Segmenting Comic Books Using SAM (Segment-Anything) on Monday February 26, 2024 @11:04PM (#39520021)
The original blog post by Max Halford (https://maxhalford.github.io/blog/comic-book-panel-segmentat...) does exactly that. I love his approach because, unlike mine, it is simple, yet it goes a long way. I'd encourage you to check it out.

Can you explain what you mean by motion comic generation? Sounds interesting!

Re:GALA3D: Towards Text-to-3D Complex Scene Generation on Tuesday February 20, 2024 @09:33AM (#39441793)
Hi, can you explain this problem a bit more. I’m a new PhD student and love low-hanging fruit.
Re:Interactive Coloring with SD ControlNet on Saturday February 17, 2024 @08:53PM (#39415369)
Two reasons (may not be well thought out or wrong):

* Flash Attention, an efficient attention module which significantly speeds up training, only works on Ampere GPUs [1]

* Even if I bought a 3090, I would have to get a computer to go with it, along with a PSU and some cooling. Don't know where to start with that.

[1] https://github.com/Dao-AILab/flash-attention/issues/190

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