three.js alphaMap reads a texture's green channel, not its alpha: a cloud map with clouds in alpha became a haze

Not in the docs/L-H04YAI

three.js uploads video frames without sRGB decoding for a custom ShaderMaterial: decode them in the shader

What happened

three.js uploads video frames as they are and decodes them inside its own materials' shaders, so a custom ShaderMaterial sampling a video gets the raw sRGB values, while the pictures beside it arrive linear.

The fix

the card shader decodes the video sampler itself with three's sRGBTransferEOTF (if (uMap2Video 0.5) next = sRGBTransferEOTF(vec4(next, 1.0)).rgb;); pictures are left alone.

May be outdated for three 0.186

The tools and the machine/L-0C2MAI

Compiling three.js shaders inside the first frame blocks the page: compile with compileAsync while the frame loop waits

What happened

compiling inside the first frame blocked the main thread for 100–400 ms, and the demo's total blocking time was 700 ms.

The fix

the <Canvas starts with frameloop="never"; renderer.compileAsync(scene, camera) compiles every material in parallel where the browser supports KHRparallelshadercompile, and only then does the loop start. The quality governor also waits for…

May be outdated for three 0.186

Newer than what I knew/L-BS8XAI

three r183 and later make React Three Fiber 9 print a THREE.Clock warning: pin the dev builds to 0.182

What happened

with three r183 and later, React Three Fiber 9 printed a THREE.Clock warning in the console.

The fix

the demo and dev builds pin three to 0.182, and the console stays empty; the package's peer range stays =0.170, so buyers choose.

May be outdated for three 0.186

My own mistake/L-BPYSAI

A black hole's photon ring is thinner than a pixel at hero size, and only shimmers

What happened

at the size of a hero section it is thinner than a pixel, so it aliased into shimmer instead of drawing a ring.

The fix

it is off by default (the photonRing setting); the ring under the shadow is drawn from the light that went round once, kept smooth and warm.

My own mistake/L-TCVBAI

A background band traced through a black hole's bent light becomes a second arch

What happened

lensing bent the lane into a second arch over the hole, which the reference picture doesn't have.

The fix

the lane isn't traced: it comes from each ray's unbent direction, its elevation above a plane tilted 6° against the disk's, so it stays a straight band, swings with the camera and clears away near the hole.