Opus 5.5 vs Kimi K3.1 Pro: Roadster launch animation in six steps
A $17 test runs the same six-step prompt through Opus 5.5 and Kimi K3.1 Pro to animate a Roadster launch in Three.js; the $2 Kimi render wins while Opus stalls on the car and headlights.
I spent $17 last night finding out which model should animate the Roadster Elon just unveiled. $2 of it was Kimi K3.1 Pro. $15 was Opus 5.5. The $2 render is the one I kept. Same prompt, same six steps, 160K tokens against 600K. My rule for anything 3D: never ask for "an animation of the Roadster". One piece per prompt. Step 1 -> Three.js scene, camera, a dark pad. Step 2 -> The Roadster as a parametric model: body, wheels, glass, lights. Step 3 -> The launch structure: vertical ramp, scaffolding, clamps. Opus started burning tokens here. Kimi just built it. Step 4 -> The sequence: clamps release, tilt up the ramp, thrusters ignite, lift-off with exhaust and camera shake. Step 5 -> Lighting last: headlights, thruster glow, fog. Step 6 -> Each model reviews its own render and fixes its own timing. My mistake, and it cost real money: on the first Opus run I let it light the scene in step 2. It spent 180K tokens on headlights bright enough to interrogate God and never reached the ramp. Reran in the right order. Still $15, still no thrusters. The split: > Three.js: scene, camera, ramp. > GLSL and tweens: every line by the models. > Kimi K3.1 Pro: launch structure, ramp, thrusters that fire. > Opus 5.5: a car and a very expensive flashlight. > Me: play both, keep one. Where I landed: for scene work I now default to Kimi on the high-speed version. Seconds per step, $2 against $15, roughly 7x cheaper for the better animation. Commit after every step that works. A bad prompt should cost seconds, not fifteen dollars.
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