# Hypot blending mode **URL:** \ **Category:** Flame Questions\ **Tags:** action, compositing\ **Created:** [December 17, 2025, 10:51am UTC](https://forum.logik.tv/t/hypot-blending-mode/13900 "2025-12-17T10:51:08Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Sinan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/sinan/32/155_2.png) [@Sinan](https://forum.logik.tv/u/Sinan)\ **Post date:** [December 17, 2025, 10:51am UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/1 "2025-12-17T10:51:08Z")
Yesterday there was a discussion on Discord about hypot blending mode. It works better than Screen and Add for comping lights and reflections. I vibe-coded a matchbox for batch but I think we need it everywhere in Flame. Please upvote the feature request: **FI-03614** [hypot.zip](https://forum.logik.tv/uploads/short-url/bkuaXJsmoI3dO0y8dnMytioP7gW.zip) (2.1 KB) ---
**Author:** ![BrittCiampa](https://avatars.discourse-cdn.com/v4/letter/b/ec9cab/32.png) [@BrittCiampa](https://forum.logik.tv/u/BrittCiampa)\ **Post date:** [December 17, 2025, 2:57pm UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/2 "2025-12-17T14:57:40Z")
I’m at the vet with a sick dog right now, but I’ll grab this matchbox and throw up a rig I made based on tony lyon’s Nuke gizmo to match blacks (that works best with hypot) ---
**Author:** ![bryanb](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/bryanb/32/136_2.png) [@bryanb](https://forum.logik.tv/u/bryanb)\ **Post date:** [December 17, 2025, 3:22pm UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/3 "2025-12-17T15:22:15Z")
**Hypotenuse** function. Instead of simply adding (A+BA+BA+B) or screening, it adds the _energy_ of the two signals (like a vector length). It works well with floating/over-range values (\>1). **Great for lights/reflections/glows** : it can feel “punchy” without washing out as aggressively as Add/Screen. You want to do this in **linear color space** ---
**Author:** ![Sinan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/sinan/32/155_2.png) [@Sinan](https://forum.logik.tv/u/Sinan)\ **Post date:** [December 18, 2025, 9:19am UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/4 "2025-12-18T09:19:18Z")
I was looking into other blend modes and found these two little gems. The second one is rather old but, so am I… > **[Help](https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_core_ac_layer_rgba_html)** > **[A Detailed Explanation of How Photoshop Blend Modes Work - Photoshop Blend...](https://photoblogstop.com/photoshop/photoshop-blend-modes-explained/)** > > A Detailed description of how Photoshop blend modes work. The math involved, and their interrelationships with each other are discussed in depth. ---
**Author:** ![AustinCampbell](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/austincampbell/32/3469_2.png) [@AustinCampbell](https://forum.logik.tv/u/AustinCampbell)\ **Post date:** [December 18, 2025, 11:50am UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/5 "2025-12-18T11:50:52Z")
Link to the feature request for those who are lazy like me: [Autodesk Feedback Community](https://feedback.autodesk.com/project/feedback/view.html?cap=5afe6c84-5cb3-447a-b36c-cbd7f0688f84&uf=a8fb5cfa-fa2a-4d7a-9c3d-818361dd7caf&slsid=6e5bb3d4-e595-4fd0-95cb-fc5b821100d0) ---
**Author:** ![BrittCiampa](https://avatars.discourse-cdn.com/v4/letter/b/ec9cab/32.png) [@BrittCiampa](https://forum.logik.tv/u/BrittCiampa)\ **Post date:** [December 19, 2025, 5:41pm UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/6 "2025-12-19T17:41:40Z")
This is the BlackMatch rig I had mentioned. Here’s the setup using Sinan’s hypot matchbox. I also included the plates used in the demo Here’s a little video that explains stuff: [https://www.youtube.com/watch?v=5BEvgE3pT9A](https://www.youtube.com/watch?v=5BEvgE3pT9A) [BlacksMatchHypot\_ForLogik.zip](https://forum.logik.tv/uploads/short-url/j4o1C2kQz6k1jaHgE8JoUFD65oC.zip) (88.8 KB) [DemoRenders.zip](https://forum.logik.tv/uploads/short-url/xuZRYJbCTLfCzNEj03totxwLuQ3.zip) (627.7 KB) ---
**Author:** ![andymilkis](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/andymilkis/32/11067_2.png) [@andymilkis](https://forum.logik.tv/u/andymilkis)\ **Post date:** [December 23, 2025, 4:24pm UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/7 "2025-12-23T16:24:09Z")
I love this!! ---
**Author:** ![nobbl](https://avatars.discourse-cdn.com/v4/letter/n/e9bcb4/32.png) [@nobbl](https://forum.logik.tv/u/nobbl)\ **Post date:** [December 26, 2025, 1:10pm UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/8 "2025-12-26T13:10:43Z")
> [@bryanb](#): > > …Hypotenuse function.Instead of simply adding (A+BA+BA+B) or screening, it adds the energy of the two signals (like a vector length). It works well with floating/over-range values (\>1).Great for lights/reflections/glows: it can feel “punchy” without washing out as aggressively as Add/Screen.You want to do this in linear color space There seems to be a misunderstanding here. The signal, as in the value of a (channel of) pixel in linear colour-spaces is proportional to the optical energy collected by photographic detector; or inversely, the output power of a picture element of a screen. Physically, the base quantity would be the electromagnetic field, which for optical purposes, we can model though solely the electric field **E** = **E** ( **r** , t), where **r** is the (three-dimensional) space-vector, and t is time. For planar waves of **E** (and superpositions of which) parallel to the detector of surface A, and shutter from t0 to t1, we measure the radiant energy Q itself the time- [t0, t1], and space A -integral over ½ε0 **E** 2. If now **E** = **E1** + **E2** , we get the total radiant energy Q=Q1+Q2 (as if calculated for the individual electric fields), **plus** the amount from the mixed terms **E1** **E2**. The latter is effectively the (positive or negative) degree of correlation, and over the time-integral will vanish for uncorrelated **E1** and **E2**. Hence, for such fields, or sources/images/…, the addition of pixel values (in scene-linear spaces) is the physically correct blending operation. The square-root of sum of squares (hypot) _would_ be correct if we instead dealt in terms of amplitudes of (uncorrelated) electric fields, which in itself would bring a lot of other caveats with it, in addition to the innate ones - like hypot as the nonlinear operation it is, being dependent on the colour-space itself (mixing under different primaries would yield different absolute colours). But for artistic purposes, naturally, it’s fair game. ---
**Author:** ![BrittCiampa](https://avatars.discourse-cdn.com/v4/letter/b/ec9cab/32.png) [@BrittCiampa](https://forum.logik.tv/u/BrittCiampa)\ **Post date:** [December 26, 2025, 3:20pm UTC](https://forum.logik.tv/t/hypot-blending-mode/13900/9 "2025-12-26T15:20:09Z")
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