I agree with what all the others said.

However, if what you mean by changing texture is using a bought or free character designed for your figure that came with material settings and all you did was double click on an icon to apply the materials then it maybe designed to look 'smooth'. This is especially true for cartoonish style textures. Or it could be a fluke that the bump/displacement wasn't figured in properly. However if the the bump is there and you still are not getting the desired results try doing what the previous comments suggested and creating your own bump map.

 

Can I ask which version of Victoria are you using in Poser?

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