How to CORRECTLY use AMBIENT OCCLUSION | Blender Tutorial

I'm here to settle the score on how to use ambient occlusion in Blender CORRECTLY. None are without sin.

Blender Manual - "Shader To RGB":
Blender Stack Exchange post:

ASSETS USED:

Rustic Brick 2:
Coastal Cliff 2:
Tufted Leather:
Hammered Copper:
Wood Trim:
Old Metal (legacy):
Timbered Brick Wall:
SciFi Panels 09:
HDRI Japan Kabuchiko Night:
HDRI Faroer Bay A:
Earth model by Denis Cliofas:

[Zev_Reef]

Warning: Shader to RGB disables Screenspace Reflections and Subsurface Scattering.

[mateuscaetano]

FINALLY!!! An actual solution to a problem that haunted me for so much time but weirdly no one talks about. Thank you SO MUCH!!!

[no-lifenoah]

The righteous fury of knowing that other people on the internet are wrong came through beautifully here.

[ButterDragon]

You deserve more subscribers, good editing, explaination with humor.

[jhallcomposer]

"You might as well just merge the AO map into the Albedo in Photoshop". I always wondered why we couldn't just don't do this instead! Thanks for clearing this out.

[MercuryRisingFast]

I love how Blender goes out of it's way to be extra difficult, and time consuming instead of focusing on more intuitive, and less time consuming. lol... But I love it!

[artjunyent]

One of the best tutorials of blender i ever saw!
Thankyou so so much!

[EmiliaHoarfrost]

Thank you very much for the valuable input. I wish you success on your Blender video career. It was short, concise, not distracting, basically excellent as far as video editing is concerned. You addressed the targetted public right away, kinda advanced/knowledgeable users of Blender.

[MisterP]

Such a simple method yet adds so much to a render. Thx for sharing I'm definitely adding this to some of my old project files!

[zakinaufal]

wow this is really a great tutorial, thank you so much!

[jermesastudio]

Thank you for sharing this. It really help me while working on my commercial projects

[varadparmar]

Wow! Great explanation bro, basic understanding and great speech - style also...❤

[BlenderRenaissance]

Make more tutorials. You have a unique appeal that will get you far.

[sanketvaria]

I always knew this so I resorted to never use thinking that AO might be a technique for old times when Raytracing wasn't as efficient and PC's weren't strong so they faked GI using AO. Hence why also used in games. So basically AO is indeed in genuine use, just that it is being wrongly used by everyone.

[fsalad]

Very nicely explained 😊😊thanks! I recently started looking into Maya hypershade utility nodes and nodes in general, am a bit slow understanding stuff, but it is so interesting

[rogper]

This should be implemented on the Principled BSDF shader... up until today I still don't know why it just doesn't have the AO input!?

[IridiumZero]

99% of blender youtubers are just affiliate marketers. They don't know anything beyond the surface level.

[npip]

FULLY CORRECT SEEN BELOW!

~ Writing in caps here because I'm trying to solve this issue, and this YT video gave me what I needed to solve it (Shader -> RGB), but the solution given wasn't working in all cases for me.

Here is the correct math that works across many PBRs that I tested:

Starting Configuration: Textures => Principled BSDF -> Shader Output

Here's what you will do (Probably putting this all in a Shader Group),

- Take the Ambient Occlusion, and multiply it with albedo (Call this node NODE_Z). Then, take the Metal texture, invert it, and multiply with NODE_Z to get NODE_Y.

- Then, add Principled BSDF -> Shader to RGB; VectorAdd this result with NODE_Y, and connect the output of this VectorAdd to your Shader Output.

This now _adds_ ambient lighting (The YT tutorial doesn't actually brighten up the texture, it only darkens, which is incorrect); and, it works correctly on textures with metal in them (This YT tutorial breaks on any texture with metallicity).

You can also multiply Ambient Occlusion with any number (1, 2, 3, 4) to match the "Ambient Light" setting in your game engine (UE, Unity, Godot), and the result should match 1:1 with the game engine. This adjusts the intensity of the ambient light. You even multiply by a color to give the ambient light a tint.

Overall, the formula is this:

ambient_light = ambient_intensity * ambient_tint * ambient_occlusion; // intensity is a float, the other two are vector3's
ambient_light *= albedo;
ambient_light *= 1 - metallic;
BSDF_RGB += ambient_light;
// If you have a PBR without an AO map, set ambient_occlusion = vector3(1, 1, 1), so that lighting is still equal across all PBRs in the scene.

Hope this helps!

[namemanu]

I am learning how to create cs2 skins and that glow in the dark effect seems really interesting to apply in the game. Would you make a detailed tutorial about how can you achieve this effect and how to bake the occlusion sheet?

[TripTilt]

now that was interesting. I'll try to use that way more now :)