Like in the picture, the reflection produces jagged effects
AA.c4d (212 KB)
Hi @123456_1 - this is a known limitation of spline rendering. In general, rendering splines with the “Renderable Spline” tag is a tradeoff of speed versus quality. Such splines are rendered as combination of cylinder or cone primitives, which results in the artifacts you have observed.
If you need better quality while using the renderable spline tag - you can try to increase the spline subdivisions, which will increase the number of primitives that will be used for the rendering (see example below - left spline uses 25 subdivisions, while the right one uses 500).
But if you really need smooth normals for close-up rendering of a spline - I suggest generating polygon geometry by using the sweep generator and a circle spline.
Thank you for your answer