a ryzen 6 or 8 core paired with a 1070.
a lot of 3d rendering programs still use the cpu so the more cores the better. things like volumetric lights are very cpu intensive especially if you have more than 1 light producing them.
a good nvidia gpu so you can use things like Vray gpu rendering.
PCPartPicker part list:
https://pcpartpicker.com/list/N7whwV
Price breakdown by merchant: https://pcpartpicker.com/list/N7whwV/by_merchant/
CPU: AMD - Ryzen 7 1700 3.0GHz 8-Core Processor ($299.44 @ OutletPC)
CPU Cooler: Cooler Master - MasterLiquid 240 66.7 CFM Liquid CPU Cooler ($89.99 @ Amazon)
Motherboard: Gigabyte - GA-AB350-Gaming ATX AM4 Motherboard ($91.98 @ Newegg)
Memory: G.Skill - Ripjaws V Series 16GB (2 x 8GB) DDR4-3000 Memory ($112.99 @ Newegg)
Storage: ADATA - SU800 256GB M.2-2280 Solid State Drive ($94.78 @ Amazon)
Storage: Hitachi - Ultrastar 7K3000 2TB 3.5" 7200RPM Internal Hard Drive ($62.99 @ Amazon)
Video Card: EVGA - GeForce GTX 1070 8GB FTW DT GAMING ACX 3.0 Video Card ($395.99 @ SuperBiiz)
Case: NZXT - Phantom 410 (Gunmetal/Black) ATX Mid Tower Case ($89.99 @ NCIX US)
Power Supply: SeaSonic - S12G 550W 80+ Gold Certified ATX Power Supply ($61.49 @ OutletPC)
Total: $1299.64
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-06-12 09:35 EDT-0400
something like this...