How to make perfect final renderings
Hi, I decided to write up a post with a good technique that i've developed to render high quality images with octane render,
within the current limitations with regards to filtering and the lack of MLT.
This technique gives faster rendering, better antialiasing and less fireflies and requires only photoshop.
beta3 will adress these issues with MLT and probably built-in supersampling and/or improved filtering,
so this way of doing it is only valid for current beta1 and beta2 versions.
I recommend people to use this technique for submitting finals.
People are welcome to post modifications of this technique using other software like GIMP on other platforms.
When you are done configuring your scene, materials and lights,
save it to an OCS project file.
Before you save it, make sure you're camera is good and you have the correct resolution for rendering your final.
Fine tune your imager/tonemapping settings for the desired exposure, camera curves, gamma, vignetting etc...
When it's saved, exit octane render.
Start it back up and load your OCS project.
Before you click on your mesh node:
* Go to the render kernel settings and change the kernel to 'pathtracing'
* Disable the 'filter' option on the pathtracing kernel options.
* Go to the render resolution settings and enter a resolution that is 2x or 4x squared the size of your desired final resolution.
example: 1024 x 512 px
2x: 2048 x 1024 px
4x: 4096 x 2048 px
the 4x is the best option, but you might not have enough video ram on your GPU left for it,
so you can go for the 2x option if it does'nt fit.
if octane exits after the first renderpass, and windows reports the driver stopped responding,
you might have to do the registry fix to switch off the GPU driver watchdog timeout, see here: viewtopic.php?f=9&t=824
* Now, click on your mesh node, and octane will begin rendering.
The screen will update very slowly.
If you are running octane on your primary display card, now's the time to go for a cup of coffee as you're PC will be occupied.
You now only need 4x less samples per pixel if you're rendering in 2x resolution mode,
or 16x less samples per pixel if you're rendering in 4x resolution mode.
* Every now and then, save your image to png with the button above the render viewport.
* launch photoshop, open the large PNG file
(you can pause octane if you're on a 1 gpu only system)
* Apply a despeckle filter -> Filter -> Noise -> Despeckle
* Change the resolution of the image back to your desired final resolution.
menu: Image -> Image Size...
Change the resolution back to 1024x512 as in my example (or any other final resolution you chose),
and use the 'bicubic smoother' filter option.
That's it, you now have a smooth, fairly firefly free, finely antialiased image.
What i usually do at this stage is an Menu: Image -> Adjustements -> Auto Levels and sometimes Auto Color too,
on some rendings this can make it look a tad more neutral.
Remember to adjust image brightness and contrast with the exposure and gamma controls in octane render instead of in photoshop,
as you will work in high dynamic range within octane's tonemapper and if you do these in postprocess in photoshop,
you will lose colour fidelity.
Posting / Submitting
If you want to supply your image for use in our artwork competitions, you should save your image to PNG format and post that.
If you save it to JPG format, you will lose quality, and if we ever put your image in our website gallery,
it will have to be uncompressed and recompressed to fit the gallery again, losing much more quality.
Attached a scene that rendered for 3 minutes, using path tracing.
The first 2 images show a straight render with and without filtering.
The 3rd image uses this technique, it has nearly no fireflies, smooth antialiasing, does'nt require a 9000 or higher GPU, and renders faster.
No manual firefly removal is needed nor any tools like hotpixels. (although running hotpixels on the 4x resolution one would be good aswell)