Light Path Node Demystified and Visualized in Blender
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- Опубліковано 10 лип 2024
- This node is so powerful, yet often overlooked. It sadly does not work too well with Eevee and will probably never work at par with its Cycles version in Eevee, but even then it's a worthy node whose applications could come in handy for anyone in various situations.
If you have any node that you think needs to be demystified, let me know and I will create an in-depth version as I did for this node.
Relevant Previous Videos:
Vector Math Node demystified and Visualised:
• Vector Math Node Demys...
If you have any queries, questions, or suggestions, comment below and I'll respond as soon as I can!
More sci-fi animations, wallpapers, loops, motion graphics, etc. using blender3D or other completely open-source free software will be coming soon! Stay tuned!
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Time-Stamps:
0:00 Intro
0:11 Understanding Render Engines
2:18 Types of Rays in Cycles
5:42 Limitations in EEVEE
6:04 Example Scene Set Up
8:11 Is Camera Ray
8:41 Is Shadow Ray
9:12 Is Diffuse Ray
9:47 Is Glossy Ray & Is Singular Ray
10:36 Is Reflection Ray & Is Transmission Ray
10:57 Ray Length
12:41 Ray Depth, Diffuse Depth & Glossy Depth
15:42 Transparent Depth
17:17 Combining Different Effects
18:40 Transmission Depth
19:49 Things you could do in EEVEE
22:50 Final Thoughts / Outro
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![Easy Blender Lighting HACK [Blender Tutorial]](http://i.ytimg.com/vi/Hyhew7kuhgA/mqdefault.jpg)
![Easy Blender Lighting HACK [Blender Tutorial]](/img/tr.png)
Knowing that "depth" refers to bounces and not a distance helps me so much.
Thanks for the comment :)
I'm glad it helped!
Many people have that misconception initially.
Tip: In case something doesn't work the way you expect it to, checking out the blender manual is always a good practice.
This made me feel like I was back in my high school physics class 😂.
This is a very comprehensive explanation without boring the viewers to "alt + F4".
Thanks for the video it was really helpful👍
Thank you so much! It really means a lot to me. I'm glad you found it helpful :)
Wow! Can't believe i just watched a whole 23 minute video in 6 in the morning, about the mighty lightpath node nonetheless! Truly an incredibly well made tutorial! Loved the explanations and practical examples, great job!
Thank you so much!
I'm glad that it was interesting enough to keep you watching!
The best video on the light path node I've seen. Thanks for making it!
Thank you so much! I'm really happy that you found it useful :)
This is the only video on the light path node ive seen.
Thanks!
I believe that there aren't too many videos on the light path node mostly because it isn't fully compatible with Eevee. Hopefully there'll be more channels using this node soon.
What a brilliant explanation. And extra credit for including a mention of Snell's Law
Thank you so much!
I genuinely appreciate it. I hope more people get into the underlying physics of it all because it often helps in unforeseen ways!
possibly the best blender light paths video. i would definitely recommend this to someone wanting to learn about it
Thank you so much!! I genuinely appreciate these comments and support a lot :)
Now THIS is how people should teach. I love how you broke this down in a way that makes the information accessible to all experience levels. Yet, you didn't detract from the complexity of the subject. Outstanding job. I subbed and would love to see more tutorials on demystifying nodes in general. Keep up the awesome job 🙏
Thank you so much!! I really appreciate it and I hope to live up to the expectations.
I'll definitely make some more videos on demystifying nodes, very soon. 😊
I was just failing with this node last night, Thank you for the tips!
Thanks!! I'm glad it helped!!
Hey my friend. I really don't know how to appreciate this. You gave me a deep understanding. I really love this.video. thank you so much!
You deserve a better laptop!❤
Hey! Thank you so much!! It means a lot to me :)
I'll possibly get myself a new laptop in the near future. Until then, this shall suffice.
Honestly, using this has helped me learn to be more efficient. So it's not all bad.
@@deayanstudios
I wish you for a brighter future.. and also I am hoping more explanations like this for nodes ❤️❤️
Thank you so much!
I'll keep making more like this, but until then, you can check out the ones I've made on the voronoi texture, Vector math node, noise texture, white noise texture, etc.
we really need this kind of demystifed content👌
I'm glad you liked it :)
We have quite a few other demystifying videos. I hope you like those too :)
Already watch some of those btw👍
Super helpful and insightful video and leaves no questions open. Many thanks.
Thank you so much! I'm glad you liked it and it really means a lot to me :)
Amazing video, thanks!
Thank you so much! I'm glad you liked it:)
incredible video - Thanks!
Thank you so much!!
I really appreciate it :)
Crazy informative thank you so much!
Thank you! I'm glad it was informative :)
amazing stuffs, best light path node tutorial at the moment!
Thank you so much! I really appreciate it! :)
that was incredibly succinct and informative, thanks man
Thank you so much! I'm really glad you think so. It really means a lot to me :)
Just brilliant! The best, most concise explanation of Light Path functionality. Now I understand. Thank you so much for sharing your knowledge. THANK YOU! Dg
Thank you so much!! I'm really glad the video is helping out! :)
Excellent expanations, thank you.
Thank you so much! I'm glad you like them :)
This is an amazing breakdown!
Thank you so much! I really appreciate it :)
Very clear and helpful to my current project! Thanks
Thank you so much! I'm glad that you found it when you needed it :)
Great explanations, thanks!
Thank you so much! I'm glad it was helpful :)
Excellent video with great examples
Thank you so much! I really appreciate it :)
This is so useful! I can't believe I've gone so long without knowing how raytracing works - I've basically just treated these "samples" and "bounces" as numbers that I can increase and it'll improve the render quality and decrease and it'll speed up the render, without actually knowing what I was doing. Thanks so much for this video!
Thank you so much!
I'm happy to hear that you found the video interesting. I realy appreciate it :)
Thanks for this ❤
Thank you for watching! I'm glad it helped :)
very good describtion, I am finally going to understand light path node with your clear explanation. thank you very much.
Thank you so much! I'm glad that my video helped you understand the light path node better :)
this is so great
Thank you so much! I really appreciate it :)
Really well explained
Thank you so much!
Fantastic explanation.
Thanks!!
Great explanation; I've learned a lot
Thank you so much! I'm really glad that it was informative :)
Very well made. Thanks!
Thank you! I really appreciate it and I'm glad it was helpful :)
Incredible explanation 👏
Thank you so much!
You are a hero I really needed this info!
Thank you so much! I am really glad that it helped you at the right time :)
Thanks for the quality content!
Thank you so much!
I'm glad you found the video to be useful :)
this is a really useful tutorial with the best explanation for light path node i ever saw on yt tutorials
Thank you so much! It really means a lot to me :)
Brilliantly thorough analysis of the light path node; please make more videos like this one and welcome to the community :)
Thank you so much! I'm glad to be a part of the community!
I'll definitely be making many more of such videos, so stay tuned :)
Very good way to explain Light Path Node. Thank You!
Thank you! I'm glad you liked it :)
Yh, the BEST explanation i have seen - i have always hated the Light path node. You might have just changed that.👍
Thank you so much!!! I really appreciate it. Glad it helped 😊
every tutorial i wanted new and accurate i couldn't find specially this one because youtube search depends on how they are famous, so old and famous youtubers didn't explain it completely, but every time i get a suggestion in your guys small channels its amazing idk why youtube didn't bring you to me at the first place, i swear you guys are underrated , hope you get more and more subs soon
Thank you so much! I really appreciate it.
I'll definitely try my best to continue improving my quality and making better videos as the days go by and I too hope that I'll get more subscribers soon enough.
goated video. TY!
Thank you so much!! I'm glad it was useful!
FINALLY a video about lightning that even my brain can compute lol...Thanks a lot - got ya a sub
Thank you so much!! I'm glad it was easy to follow along!
Thank you for the sub as well! I really appreciate it 😁
Great info clearly presented.
Thank you so much! I'm glad you think so :)
super useful❤
Thank you! I'm really glad it was useful :)
Very handy video!
Thank you so much!!! I'm really glad you enjoyed the video :)
*_Wóóóów!_*
_Thát is interesting!_
Thank you very much for these very clear explanations!
Thank you so much for the kind comment!
I'm really glad these explanations are helping :)
Best things ever man!
Thank you so much!
There's quite a few more demystifying videos coming up, so stay tuned :)
Nice explainer video. I might use this for a logo animation.
Thanks!
Good luck with the logo animation! I'm sure it'll come out to be amazing!
excellent video.
Thank you so much! I really appreciate the motivation :)
Nice video!
Thank you!! :)
Very nice explained, i will see your other videos, pls make more tutorials like this one!
Thank you so much!
I will definitely be making more like this!
For now, I have videos on the Vector Math Node as well as the White Noise Node and I will be adding in more nodes and converting it into a series very soon! I hope you will enjoy them as much as this one :)
I will watch your Vector Math Node video as well!
I will be glad to see your explanation of how attributes are replaced in Blender 3.6. New workflow!
Alright!
I'll definitely take a look at that and see if I can contribute to an explanation and if I can, I'll make a video on it too!
Thanks for the suggestion.
I wish I was just a little better in mathematics, such a great tutorial thank you so much
Thank you so much!
It just takes a little bit of practice and the will to understand exactly what's being done and with that much, you will definitely get much better at mathematics very soon!
Good luck!
Fantastic tutorial! You explained everything needed!
One little nitpick/suggestion: it would be nice if you avoided strictly white backgrounds for text. It felt fine at the render part, but the first six minutes I had to squint my eyes :P
Thank you so much!!
I'll definitely keep that in mind for future tutorials.
Awesome video; Subbed
Thank you!!
I really appreciate it.
the enthusiasim for 3D menifests itself in this video.
Thank you so much!!
Holly shit dude, that was awesome. Thank you!
Could this be useful for rendering out reflections only? For example, like a shadow catcher, but a "reflection catcher"?
Thank you so much!
This could definitely be used as a reflection catcher.
The is camera ray could ensure its transparent to the camera, but an is reflection ray could make sure the reflection remains.
Amazing, thanks again. @@deayanstudios
Very informative, every time i watch i learn new things. Please explain about baking light, texture, material on object for fast render animation
Thank you so much!
I'll definitely try to make a video on that someday soon as I am sure it would help out a lot of people! Thank you for the idea!
I did not know about how shadow rays work. Thanks, I've been wanting to make the toon shader's shadows have a different color for a while.
That's great! I'm glad this helped and I hope you'll be able to get the exact effect that you've been trying to achieve with your shadows now!
@@deayanstudios Looks like I misunderstood how they work. I thought it effected self shadows, but it mostly does not.
In my testing, I was able to turn any shadow (both shadows cast on itself or onto other objects) into whichever color I wanted.
If you can explain exactly what you're searching for in some more detail and maybe send me a blend file of what you wish to achieve, I can take a look at it and try to help you achieve that.
Remember, the object casting the shadow has to have the mix shader with a transparent shader determining the color of the shadows that are being cast. Apart from that, you must be using cycles.
@@deayanstudios I'll explain further. I set up a test sphere, a light, and a camera. I thought I could use this to change the color of the shaded part of the sphere, but it dud not. It did, however, change the color of other objects I put in it's shadow.
Hey, so I understand what you were trying to go for.
I think it would be much more powerful if you used EEVEE. However it is possible in cycles as well.
I have uploaded a tutorial that will show you how to solve your problem in both Cycles and Eevee, I really hope it helps :)
ua-cam.com/video/99IP_NiF7RM/v-deo.html
Do let me know if this helps :)
I had Ray Tracing backwards. I thought the paths were generated from the light and either hit the camera directly or eventually bounce in. I guess it does make way more sense to reverse engineer the lighting based on the camera's POV though, as calculating from the light would likely be very memory intensive with many of the calculated rays never reaching the camera. Basically a ton of wasted math operations.
Ah yes, I too had the same misconception when I initially started.
The various optimisation techniques used in render engines is genuinely astonishing.
If the rays come from the camera how does the algorithm know what areas are affected by the light
@@iluvpandas2755
It traces the path backwards from the camera to the light source, through any necessary bounce angles. My guess after that is a ton of math I couldn't possibly comprehend. LOL.
@@iluvpandas2755 Each Ray has a max number of bounces set by the user. The last bounce will always go towards a light source. If it is blocked by an object, it will simply be dark. However, over multiple samples, it'll slowly average the value out, to create a realistic amount of light for that pixel.
That's why sometimes with low samples, you get really dark spots in random places, which makes the image very noisy overall..
Good explenation
Thank you so much!
GREAT GREAT information! I mostly use Is Camera Ray in World to hide an HDRI background image but still have the light of the HDRI work. e.g. Texture Coordinate -> Mapping -> Image/HDRI -> Background -> Mix Shader top input, (Light Path Is Camera Ray to Mix Shader Fac, second Background to bottom Shader on Mix Shader) -> World Output. With your tut i will for sure explore more of what Light Path can do in my renders!! THANKS!!
Thank you so much! I'm glad it helped.
The use of this node for HDRIs is very powerful and it's also where I use it the most. Thanks for sharing the process here so others can follow along and try it out :)
is there any difference between doing this and just doing Film -> Transparent in the render settings?
Using Film transparent will allow you to render out transparent backgrounds and if you choose not to have transparency, the background will be black only.
By using this method, you can customise the colour of the background to whatever you want, while having the scene lit up using an HDRI.
@@deayanstudios i guess so but with the transparent you can add any image or colour or gradient in the background with the compositor nodes
Yes, that's possible too. Just another way to get similar results.
That's the best part of softwares like this. There are many ways to reach the same end goal
i love you!!!
Thank you so much!!
What I want to see is a tutorial on how you did the intro! nice.
Hi! Thanks!
The intro was made as a combination of the following two tutorials:
The electric arcs:
ua-cam.com/video/TKQsIw2XMyw/v-deo.html
The metalic node:
ua-cam.com/video/356AkOyANDc/v-deo.html
great
Thank you so much!
Thanks a lot. Do more deep explanation of other staff. Very good job.
Thank you so much!! I really appreciate it :)
underrated Video
Thank you so much! Means a lot :)
@@deayanstudios I understood every single thing bro, and the way you explain and switch to the next topic is flawless, Subbed
Thank you!! I really appreciate it!
I never thought physics would be helpful in this profession. Finally, my physics teacher's existence makes sense to me😂. Although I am not good at physics, I understood the concept to its depth. Thanks a lot for the quality content. You gained a sub.👍
Thank you so much! I really appreciate it :)
Knowing math and physics actually comes in handy in many areas of 3D animations, texturing and Motion Graphics. I try my best to explore multiple applications of math and physics within many of my tutorials
Does this node affect the light rays coming from some light source? for example from lamp in the scene?
Not directly. The light coming from the lamps will remain the same. However the way the light appears after interacting with certain objects can be changed using this node.
Great video, thank you! But I still don't understand the example with background in evee. How exactly we get different results if in evee all rays are going to the camera? I'm talking about making two background nodes so that object get lit in one color and background get another color. IF all the rays in evee are camera rays than everything sholud be in the colour from the second background node, right?
Hi, thanks!
Not all rays are camera rays in eevee. Rays that do not come from a diffuse, glossy or transparent objects are camera rays. If they originate from a diffuse/glossy/transparent object, they will not be considered camera rays.
I hope that makes sense and clarifies your question.
Thank you! @@deayanstudios
Wow, how do you learn blender in that much depth?
Thanks!
It always starts with reading the blender manual and documentation.
From that point on if you still wonder about how things are done, you can always search up various research papers and articles that often explain all the algorithms in very good detail.
how can i know the number of how much time the ray was reflected when it comes to ray depth?
So the ray depth is used generally when you want all the rays of a specific number of bounces to be changed. If you don't know exactly how many bounces a ray is undergoing, you'll need to use trial and error until the desired ready is affected.
👏👏👏
Thank you :)
Why don't I have any nodes for the lights or why is it not possible to put them in nodes?
Nodes for the light shaders is possible only in cycles.
It'll allow you to create custom light profiles and gobos, but you'll need to check the use nodes button within the shader editor, with a light selected while in Cycles.
I'll definitely make a video on this technique later on in a few weeks.
Till then, I hope this explanation helped.
Why did you remove the "save" option?
Hi, I didn't play around with any of the default UA-cam settings.
Was it possible to save the video before, but not possible anymore? I'm not sure why that might have happened. I'll take a look at it.
❤🔥❤🔥❤🔥
Thank you so much!
Huh, I always thought that ray tracing worked the same as actual light physics, where photons bounce off of materials and the ones that hit the camera are the ones we see in the scene
I had the same misconception when I first started blender. However, that would be an extremely inefficient algorithm.
The light sources would not know which direction light is to be emitted and hence there would be hundreds of thousands of rays that are calculated, but never reach the camera. Considering that each ray could have multiple bounces as well, it ends up being very impractical for the computer to handle. Which is why we back trace the rays, resulting in the same outcome, but just far more efficiently.
Very nice explanation. also use lubuntu instead of debyan, it is much faster and lightweight.
Thank you so much!
I'll definitely try using other operating systems sometime. Thanks for the suggestion!
I personally prefer Manjaro.
Danke . thx . merci
💪💥🗯💭💨❤🕊
You're welcome 😊
Thanks for the comment!
i am very sad to inform, but you can not use light path in combo with displacement
(it wasn't mentioned in the video, but it would be cool)
Ah yes... It's definitely sad that the combination of those don't gel together.
The displacement in cycles caused by a parallax method, which essentially would be very hard for the light path node to calculate. Maybe some day in a future update?
Slow down
I'll definitely try to go a bit slower in future videos.
Great content but ... speak slower
Thank you so much!
I will definitely try my best to slow down to make it more accessible to everyone.
Thanks for the advice :)
Amazing video! finally a detailed video talks about the light path node, but can you show us some tricks using each light path node? Only theory is a bit too abstract.🥸
Thank you so much! I'm glad you enjoyed it!
I'll definitely be using the node in practical examples in future tutorials, once I start making things using the Cycles render engine.
But thanks for letting me know. I'll try to add some practical examples in future demystifying videos. Thanks!