Fixed the issue of not displaying when rendering multiple tilemaps (#18695)

Author: qiuguohua

cocos/tiledmap/assembler/simple.ts

@@ -74,9 +74,6 @@ class Simple implements IAssembler {
             const batcher = director.root!.batcher2D;
             _accessor = new StaticVBAccessor(device, vfmtPosUvColor);
             //batcher.registerBufferAccessor(Number.parseInt('TILED-MAP', 36), _accessor);
-            director.on(DirectorEvent.BEFORE_DRAW, () => {
-                _accessor.reset();
-            });
         }
     }
 

cocos/tiledmap/tiled-layer.ts

@@ -1520,11 +1520,10 @@ export class TiledLayer extends UIRenderer {
 
     private fillIndicesBuffer (renderData: RenderData, drawInfo: RenderDrawInfo): void {
         const iBuf = renderData.chunk.meshBuffer.iData;
-
-        let indexOffset = renderData.chunk.meshBuffer.indexOffset;
-        drawInfo.setIndexOffset(indexOffset);
         let vertexId = renderData.chunk.vertexOffset;
         const quadCount = renderData.vertexCount / 4;
+        let indexOffset = (vertexId / 4) * 6;
+        drawInfo.setIndexOffset(indexOffset);
         for (let i = 0; i < quadCount; i += 1) {
             iBuf[indexOffset] = vertexId;
             iBuf[indexOffset + 1] = vertexId + 1;