Just a few "quick" responses.

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dr_bernie wrote: "The issue of CPU versus GPU based renderers will never be settled. Each technology has its supporters, and we can debate it for months without any tangible results."**

Actually, my last post was more about demonstrating why you can't really consider Embree and GPU rendering to be equivalent technologies, and that no matter how much Embree improves perfomance, under equivalant conditions, there is no way that current common single box cpu configurations can even come close to GPU processing power/capabilities. This is simply a matter of available instruction/computation cycles per second on each respective processing platform.

If you don't want to use GPU based rendering, that's your choice. I just wanted to make it perfectly clear to anyone reading this thread (if they haven't fallen asleep half way through it) that even though Embree might make CPU rendering faster, it will still be slower than GPU rendering, and why.

dr_bernie wrote: "What I am trying to do is to see which one of Embree or Octane make more sense for Carrara."

Honestly, at this point this is kind of academic, and sort of a mute issue. This isn't an either/or proposition. The plugin for Carrara is being developed, regardless. When it comes out, you, and every other user of Carrara, will have the option to either purchase and use it, or not. If you don't want to use GPU rendering with Carrara, great, that's your choice. But I can tell you that most people I've communicated with who have actually tried Octane find some real value in using it - your mileage may vary.

dr_bernie wrote: "3. Embree will run natively in Carrara and will support Carrara's lighting and shading systems, including hair shader and volumetrics, for a total estimated development cost of 6 months or $100K.-, asuming that the developer assigned to the project knows what he/she is doing."

Really? Everything I've been able to find indicates that Embree 2.0 does not support shader based hair or volumetrics (including an Intel generated Q&A sheet on Embree 2.0). Where did you find that it does support these?

I think integrating Embree into Carrara could be a really great thing. The question arises though, why haven't more companies used it, or announced that they are integrating it? I think quite possibly some may have already integrated many of the SSE instructions into their code, and retooling everything to include Embree to get what might be marginal performance gains for them, simply isn't worth it. Or, they may be waiting to see if the next version of Embree will include support for features that are currently missing. Only time will tell how wide the use/acceptance of Embree will be.

Regardless how much it might cost, or how great it would be for Carrara, talking about it here will do nothing to promote the idea with the owners of Carrara. You really need to present your case to DAZ (I wouldn't say this if I didn't see merit in it).

dr_bernie wrote: "5. Embree could make Carrara's renderer go up to 30x faster by my estimate, while at the same time improving the render quality noticeably. This is more  than enough for most Carrara users. Actually if you look at this list (link) of all the movies rendered with 3Delight, which is a CPU based renderer, you will wonder  why the producers of these movies did not use a GPU based renderer. Certainly it is not a question of budget, since these guys have all the multi-million dollars budgets that they could wish for. Therefore there must be other reasons. Render quality maybe? Or speed? Or reliability in handling large projects?

First, how are you generating your speed improvement estimates? Have you run actual tests that indicate this, or just guessing based on what you've read. If I were to send a feature request to DAZ, this would be an excellent point to include, however without real data to validate my claims, I could only say that based on what I’ve read, there could be significant speed improvements with the implementation of Embree.

I don't have to wonder why the big studios aren't using GPU based rendering, I know why. Here are the obvious reasons. First, typically their scenes won't fit into video RAM, and it's not uncommon to have scenes in the 16-32Gb range. Second they have huge investments in projects that run over multiple years (i.e. Pixar usually has four films in their pipeline at the same time, each one taking about four years to complete), they can't afford to change render tech mid stream as this could require re-working everything done prior to changing to the new tech. Third they need to have a stable, proven environment for their massive render farms, GPU rendering isn't there yet. Fourth, they use biased render engines to improve render speed, and create special effects in the render rather than in post - the focus for GPU renders has been unbiased, as that is where the speed increases are most needed.

Also, keep in mind that even if GPU rendering made sense for them (and at this point I honestly don’t believe it does), it would be a huge undertaking to move to a GPU render farm. They would have to either purchase, build, or rent additional facilities to build the new GPU render farm, because it is highly doubtful they would transfer any current productions to GPU rendering – there is just too great a chance that there would be inconsistencies in renders that would be unacceptable. Second, it would require a whole new team to manage the second render farm, the purchase of thousands (yes thousands) of computers and vedio cards for the new render farm, and no doubt re-engineering workflows.

I don't think anyone using Carrara has requirements similar to the big Hollywood studios. In fact, I doubt very many users even do network rendering. Octanes target demographic is more the small graphics/3D studio, architects, freelancers, and serious 3D enthusiasts. They definitely aren't targeting even medium to large studios, as Octane has no multi-computer rendering controls built into the software (render nodes).

Now really, in you last sentence your actually questioning the quality of unbiased GPU renders??? You do know what unbiased is don't you? But seriously now, there can be some background flickering issues using unbiased renders for animation However a quick look through the videos posted on the Otoy site shows that this probably isn't an issue with Octane (Si Fi Funk is already working on moving his workflow for animations to Octane)

While we're on the subject of the big studios, you are aware that Pixar has incorporated GPU rendering in their workflow aren't you? If not, take a look at this video, pretty cool tech. Set up all your lighting near real time using Nvidia Optix GPU rendering tech, then us Katana to consistently transfer the exact same lighting setup to PRman for final production. So, even though GPU rendering isn't being used for final production work, it is definitely moving into, and accelerating the workflow of the big studios.

dr_bernie wrote: 6. Embree will positively contribute to Carrara sales going through the roof, i.e Embree could potentially turn Carrara into a self-sustaining product. This will be a huge benefit for Daz, for Carrara PA's, and for Carrara users, because nobody wants to drag along, develop contents, or work with a 3D app whose future is uncertain.

I would like to know where you are getting your estimates for these sales figures. Did C4D, Vray, or Simlab sales go through the roof because of the addition of Embree? I'm all for something that will improve Carrara's sales and use. I ask because you state this as fact, so you must have some information on another similar situation. I have no doubt that it would be a great upgrade bullet point, and that it very well could increase sales. But, if I sent an enhancement request to DAZ, before I would include a claim like this, I would want to be able to include real data to back up my claim.

 

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