#430 World shadows jump to a second sun angle for 0.33 s every ~1.3 s (any shadow-map mode, DX11 and DX12)

Status: Open · Area: Graphics & Art · Lighting & Shadows

All world shadows periodically jump to a second angle and back every second or so, as if there were two suns.

Current behavior

(Client 1.60.1.70532.) With shadow maps on, every shadow in the world periodically jumps to a slightly different angle and back, as if there were two light sources. It is easiest to see on tree shadows on open ground with the character and camera standing still. The timing is very regular. I measured it frame by frame from screen recordings (60 fps capture): - the shadows flip to the second angle, stay there for 0.33 s, then flip back - the cycle repeats every ~1.29 s (0.96 s normal + 0.33 s flipped), about 90 flips per minute - the rhythm is real-time: it does not change with the frame-rate cap (maxFPS 20, 30, uncapped all give the same timing) What I tested (one setting at a time, standing still, measured over 20 s each): - DirectX 12 and DirectX 11: same - graphicsShadowQuality 3, 4, 5: same - shadowMode 2 and 3: same. shadowMode 1 (blob shadows only) is the only setting without it - shadowSoft 0, shadowBlendCascades 0, shadowNumCascades, shadowTextureSize 4096: same - giQuality 0 (global illumination off), graphicsLightMode 0/1/2: same - vrsWorldGeo 0, vrsValar 0, vrsParticles 0 (the VRS fix from #384): same System: RTX 3060 12 GB, NVIDIA 610.57, i9-12900, 3840x2160. I play on Linux (Proton), but the same symptom is reported by Windows players on the official forums (link below), and it is identical on both graphics APIs, which go through different translation layers here, so it looks like it's in the client's shadow update rather than the driver or platform.

Expected behavior

Shadows stay still while the sun moves slowly and smoothly with the time of day, with no periodic jump to a second angle.

How to reproduce

1. Graphics: shadow quality Fair or higher (shadowMode 2 or 3), DX11 or DX12.
2. Stand still on open ground next to a tree shadow (I used Lake Mennar, Azshara; also seen elsewhere), camera still, top-down helps.
3. Watch the shadow edge: about once a second it jumps to a slightly different angle for a third of a second and snaps back.
4. /console shadowMode 1 makes it stop (but only blob shadows remain).