🚩 Rendering itself is by far the easiest step. Here, we will just share a few considerations on performance and memory.
⚡ Before the final rendering, make plenty of incremental render tests.
💡 The point of rendering is that it should look noticeably different from the modeling viewport. This means that intermittent quick render tests are frequently needed. More than 99 % of all frame buffer starts are for quick testing. Use render regions and increase resolution gradually. Resolving more details helps spot new weaknesses to amend.
⚡ Ramp up the resolution generously for the final render.
💡 Using higher resolution than strictly necessary may give more freedom in the post-production stage. High resolutions bring weaknesses to the fore, encouraging discipline.
Render times will vary greatly depending on scene setup. If you know how a renderer works under the hood, it is easy to make scenes that more or less break it. That said, for typical scenes at up to about 10 megapixels, any current computer should calculate a complete production render at least overnight.
Many want more raw performance. The longing for performance is mostly some kind of computer nerd revenge fantasy. Few really need it for artistic reasons. By liberally test-rendering in interactive mode, your production render should be free from big surprises. It is rare that the actual problem sits in the computer – more often, it sits in front of it.
That said, more performance is good. Get a faster system if you can. If you find yourself needing still more cpu performance on a regular basis, try local swarm rendering or cloud rendering.
Switching to gpu on an up-to-date graphics card can be much faster than an old cpu. Note that gpu still does not support all subtleties in materials and lights, and is bound by the graphic card’s typically soldered ram.
Calculation times are one thing. But when scene complexity and output resolution soar, available system memory can set a hard upper limit to output resolution. If your computer runs all out of memory, your render will crash. The memory tax is as real as real tax.
⚡ Guard yourself against out-of-memory crashes by adorning your system with more ram.
💡 How much ram is enough? A good baseline is twice that of your smug rendering colleague’s. If system modification is not an option, there fortunately still remain many ways forward.
⚡ Deploy memory-conserving methods to enable larger scenes and output resolutions.
💡 To conserve memory:
· Turn off or delete needless geometry. For scattering, use features like camera clipping.
· Render in bucket mode rather than progressive mode.
· Turn off displacement. Use only where necessary.
· Turn off render channels.
· Turn on features like embree conserve memory.
· Close all needless concurrent programs.
· Export your project as a V-Ray scene file and render it with V-Ray standalone, bypassing the host modeling application.
· Make several lower-resolution renders and then stitch them together in postproduction.
· Render with V-Ray Cloud cpu.
⚡ Finally, make sure Save image is enabled – for instance to a multichannel exr – then hit that render button, or preferably, use a shortcut to start rendering, sit back, and relax until it has finished.
😄 – Done!
🤔 – No.
😦 – Hey, we’re through now, aren’t we?
🤨 – Not so fast, mister. You’re forgetting one thing…
There is always “one more thing”… Join us next week!