iRay verus let's say Octane.. speed

[Cesar R]

Why is iray so slow compared to other real time engines?

at first I thought is was the GPU I was using, however after trying several engines (demo) I have noticed that iray is very slow when it comes to camera view updates and such.

 

Not bashing iray, I really like MR and I wish they were quicker. I am a revit user and really like the 3dsmax workflows I have developed.

[Phillip Miller]

Are you examining the speed of iray via its use in ActiveShade or as rendering requests via the render dialogue?

Then, are you comparing the interactive speed or the rendering speed (the time it takes to achieve a finished image) when you compare renderers?

 

Also, what type of GPU(s) are you using?

 

- Phil

[Francisco Penaloza]

Well yes, there is different speed depending of the software, each company has his own way to do the progressive path tracing, Maxwell, VRay RT, Ocane, Fry Render, and many more, each one of them develop his flavor for this trend, now IRay is very tight with NVidia CUDA development, so NVidia want you to buy the most expensive GPU cards combinations possible for you to have fast interaction with IRay, rather than other render engines that they just want to be fast

Remember Brazil render? well now they joint with Caustic company and they are trying the same NVidia Iray combo, develop the software and the hardware.

Ocane render has 2 ways to render, one is an approximation or fake AO the other one is the real path tracing, of course this one is slower but precise.

MODO as the fastest RT that I know of, is CPU based and you get all the effects that a regular render has, caustics, dispersion, scatter, Proxies, special shaders, that's the power willing to develop a good software without boards members asking you for more profits

[Cesar R]

^ very interesting answer / angle. Makes total sense from a business POV (which is important in all). However technically, would you say that in the Active render and even in the render windows iray wants to do its calculations more precisely than octane and hence it takes longer?

[Francisco Penaloza]

well I am not a programmer or that technical about it, so hard to say, all companies brag that their software is "the real thing" but if you look at their development, they archive feature little by little, V Ray RT was not able to do displacement, I Ray had problem with dispersion and caustics, Octane didn't do displacement, now Maxwell is offering grass system, so it depend really.

There is different way to approximate Fresnel effect, each one has his advantages and problems so for me is always about the consumer that decide if this or that software fits for their special work flow. I don't buy the thing of "this is the real Physically accurate way to do it". I like the artist freedom to tweak and adjust depending of the story you want to tell with your image/video.

But hey this is my opinion, so take it with a pint of salt

[Cesar R]

I agree with you. I am just wondering why is it that octane can cook a "real time" render so much faster than than iray. I am talking extremely noticeably. Someone asked about the GPU. I am using a very low end here at the 9-5 office GTX 620...

 

At home I have a 670Ti to install and try out.

Edited January 24, 2013 by Cesar R

[Cjmcphail]

I agree with you. I am just wondering why is it that octane can cook a "real time" render so much faster than than iray. I am talking extremely noticeably. Someone asked about the GPU. I am using a very low end here at the 9-5 office GTX 620...

 

At home I have a 670Ti to install and try out.

 

How does your GTX 620 got with heat

[Cesar R]

not sure, I will have to see next time. I don't think it got too hot. Remember it doesn't have many CUDA cores.

Edited January 25, 2013 by Cesar R

[Dimitris Tolios]

GPU accelerated renderers are claiming to be "unbiased", i.e. taking the brute force route in ray tracing.

That said, it is also obvious that each programmer has its own way of setting up the acceptable tolerances the rendering engine will operate within. Different algorithms and optimizations can lead to varied results in both quality and speed.

 

Depending on your "wants", some RT GPU engines might suit you for their speed, others for their accuracy (under ofc your subjective or artistic POV) in complex scenes (interiors, low light conditions, caustics, complex materials etc) and in some cases you might say that you don't care for their limitations and you prefer to push forward with the classic CPU production renderers.

 

Like it should be, there aren't always cookie-cutter answers

[Cesar R]

That is true, I guess in my comparison I would say that iray seems to like to use more a brute force approach.

I appreciate your response ! Thank you.