I place a standard shader ai on topology,and render,but I get a Xmas tree effect? Can anyone help

[Anonymous]

autodesk3.pdfautodesk2.pdfautodesk.pdf

[lee_griggs]

Does it happen with just this scene? Could it be a graphics card issue? What happens if you disable textures/shaders?

The Standard shader is deprecated now. If you are using Arnold 5, you should use the Standard Surface shader.