BN: The Cycles F.A.Q

Ever since Brecht announced his work on a new GPU-powered renderer Cycles, it’s been the biggest buzz in the Blender community that I’ve seen in a long while. If you need to catch up,…

[read the full article on blendernation.com]http://feeds.feedburner.com/%7Er/Blendernation/%7E4/Kt-0uF0Lcfw

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After Cycles replaces the Blender Internal, will they still leave it there (perhaps as an addon) so that people can still use it if they want to? That would be great.

Why would anyone want to use BI?

FreeMind - you wrote that Internal will be gone in a year or two. I understand that this is the time needed for Cycles to be ready? Is there any schedual for new releases? I also understand that development of Blender Internal is now abandoned?

wesburke doing blender news ;D cool. I guess blendercookie is more than 50% of the traffic for cgcookie nowdays.

Here is link to faq.
http://dingto.org/?p=157

it’s a bit like saying “why would anyone use any other renderer than cycles?”
Because it’s good for a lot of stuff, bad at others…

cycles will be good at different stuff and bad at different stuff…

it’s the nature of the beast that one renderer does not fit all tasks…

Approximate AO is great in BI (but in some situations becomes impractical…) but AAO will not get added to cycles because it needs a pre-processing step… which is against the first rule of cycles design…

SSS is great in BI, but because it has a pre-process step means Cycles implementation of SSS will also have to be different…

which means these sorts of fast approximations will have to be implemented in a different way that is compatible with instant progressive rendering… which will have a different bottleneck… (probably more time to converge…)

It’s interesting of you read the FAQ that GPU rendering already means some stuff will take a lot of work and may never get supported unless you use CPU…

Mostly external libraries that are currently CPU only: stuff like Ptex and OSL…

I’d agree that BI will probably not get updated much, but hey, it’ll still be the best choice for a lot of stuff for a long time… and even when cycles has all teh same or better functionality (motion blur, hair, particles, sun lamps, scattering, render passes…) BI will likely still be better in a few cases.

I’d love to see BI extended as a glsl renderer too… as it is now + viewspace AO, motion blur, shadows/soft shadows from all light types and dof…

When you have tools for photorealism, don’t forget that it’s not necessary for everything to look real.

Cycles is a phenomenal tool for physically correct photon-based rendering with GI and caustics and such, but there’s a huge demand for simple non-photon-based renderers too. I make stylized animations with Blender, that need to render fast, noise free and don’t require any physically correct rendering. Here’s an example. Animations like these are rendered best with something like BI or OpenGL-export. It would be very foolish to stop developing these simpler renderers.

The render branch is on the list of possible branches to be included in the upcoming development, so there is still some improvement to be had. I’ve always had an inkling towards animation and optimizing for it, so for me BI is awesome in that regard. At the same time, Cycles is very interesting, because it will eventually be an engine for animations.

Jay

really ??? This would be great new - I found it quite decent to use for animation. The lack of AAed raytraced mirror reflection and the slow speed were an issue for me however. It would be great in case they could just speed it up and leave BI at that.

I think it is a quite great system for semi realistic to graphical render styles.

As great as Cycles is - it is not that fast on my computer where a smart light rig can be enough to get the desired look.

lack of AAed raytraced mirror reflection and the slow speed were an issue for me however
In my experience I’ve never attempted AAed raytraced reflection in an animation (I’d probably cheat it), and in my experience I’ve never had a frame render in over 20 sec, with nodes. Then again I was rendering for internet output, so not that huge. But, I was making my work with animation in mind- that’s a specific goal. Low poly and minimal texture size, plus the technologies that were animation friendly. I think if you are starting off with animation in mind you tend to optimize towards it.

Edit: and given BI’s history, Cycles will be an animation friendly engine, I feel in the end it will be optimized toward motion. When sculpt first was developed, I almost crashed my system playing with it, when the optimizations were done, it was no problem at the same res. Cycles as we are seeing it is un-optimized, I believe it will be much nicer in future iterations.

Aa retraced reflection is much much faster in the 2.5 series… I’d agree that it gets slow when you reduce the glossyness.

I was really pleasantly surprised that a straight reflection had little impact on speed for a scene I was rendering at 720p a few weeks ago…
(in BI)

I agree with jay though. It’s easy to fake reflections with nodes for fast render times…

Cycles doc and glossy roughness and Gi are a thing of beauty though!

Thats what I would love to see!!! I think the GLSL rendering could be very powerfull!!!

This imagefor example looks almost the same for me in GLSL. Of course I have some postproduction on this image, as DOF, some color correction and so on. But imagine what would be possible if the glsl renderer gets some love so you can use it with your compositing node system!!! At the moment my render of this image(1920x1200) takes about 50 seconds. As an GLSL Renderer with opencl support for nodes this will probably Render less than 10 seconds!


But I also have to say, that I love to use the BI Renderer!!! I really don’t understand why people say it is useless… I just think most of them just don’t have discovered it’s power yet(press render and expect an awesome result as in cycles)!!! Or just don’t know how to properly use it! Of course it is not suited for all tasks, but I also think that even realistic product design is possible with it!

I am also looking forward to the cycles renderer! I hope it will give me as much freedom as the BI! That is what I really love about the BI renderer!!!

Just my 2 cents ^^
Andreas

When you have tools for photorealism, don’t forget that it’s not necessary for everything to look real.

Don’t think that Cycles is only for photorealism. It’s really not.
It may be very limited at non photorealism now (Use 0 bounces and get BI like render)
But i bet it will be good at this in the future.

FreeMind - you wrote that Internal will be gone in a year or two. I understand that this is the time needed for Cycles to be ready? Is there any schedual for new releases? I also understand that development of Blender Internal is now abandoned?

Is Cycles can use cpu AND gpu for one image?

I also understand that development of Blender Internal is now abandoned?

Nope, it’s not. Well, not yet.
Quote Brecht:
“There may of course be developers that want to continue developing Blender Internal, and the intention is not to drop it immediately.”

I understand that this is the time needed for Cycles to be ready?

Depends on what you mean by “ready”.
It might or might not be ready for merging for 2.6. The plan is to release a version of Blender every 2 months, so 2.6 is going to come in somewhere around 3.5 months. It doesn’t have to be feature complete to get merged, it just has to be stable, clean, easily compiled, etc.
But BI won’t leave until Cycles can do everything BI can and more. Which will take years.
Once Cycles reaches that point, there is no more use for BI.

Is there any schedual for new releases?

There is no such thing for cycles. It’s only speculation. However, it always takes longer then one expects.

Is Cycles can use cpu AND gpu for one image?

Not yet.