Update: There’s a 2.76 build on page 12!
Now that 2.74 is released, it’s probably time to post a new build with all the experimental features I’ve been coding in the last time. However, since each feature has its own thread, I’m just creating a new post here
It’s based on the 2.74 release commit, with Adaptive Sampling (D808), Tonemapping (D947), Light Portals (D1133), Hilbert Curve Sampling (D1166) and a Shadowcatcher (not submitted yet) on top of it.
Quick summary of the features:
Automatically stops tiles from rendering once they’ve reached a certain quality level.
Important: The “regular” sample limit still applies (if you want to diable it, just set the samples to something like 1000000)!
The settings panel only appears in Experimental mode. “Adaptive distribution” should be enabled for bigger tiles (roughy 32x32 and above). The Confidence slider sets the quality (80 is pretty conservative, 60 should also be quite clean). Map interval can remain at 25, you should only lower it for Branched Path Tracing (it sets how often the error estimate is updated, and since BPT needs fewer AA samples than regular PT, it should also be lowered).
Reduces the dynamic range of the image, often used if certain parts of the scene are too bright.
The setting is called “white value”, it’s found under the color management settings in the scene tab. It sets the brightness that will be mapped down to brightness 1, in stops (just like the exposure). 0 means no tonemapping. Tonemapping is applied between exposure and gamma control.
Portals reduce noise when rendering interiors with background/HDRI lighting. The resulting image should be the same, but with portals it will require less samples (although each sample will take slightly longer).
To add a portal, add a Area Lamp and check “Is Portal”. This will disable the lamp and use it as a portal instead. Note that portals are unidirectional and will only be used in the direcction into which the area lamp points.
Portals should be used to cover the main areas where background light enters your interior. Less portals are better, so for example, two windows next to each other should be covered with only one portal.
Adds a new tile sampling pattern. Hilbert curve will render slightly faster than Center, and IMO it looks awesome
This is just an experiment of mine, I’m not too sure whether it will be useful in practise. Anyways, to use it, set your plane/whatever to use the “ShadowCatcher” BSDF and activate Film Transparency. Also, to account for shadows from the background/HDRI, you must enable Multiple Importance Sampling for it.
Also, there currently is a bug if you plug the ShadowCatcher into a Mix Shader with a Factor that’s not either zero or one. This means that mixing based on i.e. “Is Camera Ray” works, but a 50-50 mix of ShadowCatcher and diffuse won’t.
Enough talking, here’s the build:
CUDA works, this time the sm_52 kernels should also be included.
I can only build for Win64 (no Mac here, and I’m too stupid for static linking on Linux;)), so if anyone could build for Mac/Linux, that’s be awesome! Here’s the patch, apply it to the v2.74 tag (commit 000dfc03):