Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: rdawlud on 2015-12-04, 17:30:42

Title: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: rdawlud on 2015-12-04, 17:30:42: Hello. I am playing with motion blur in corona and I can't achieve effect which I am doing in vray. Corona blur is a little bit different. More like simple motion blus in PS and in vray this is much more realistic in my opinion. Can you tell me is it possible to achieve blur like I want? I tried different options and a lot played with settings but result is not good for me. Thanks for help.

Greetings,
Rafal

Corona:
(http://i1375.photobucket.com/albums/ag467/rdawlud/corona_zpstlefd9ch.jpg) (http://s1375.photobucket.com/user/rdawlud/media/corona_zpstlefd9ch.jpg.html)

Vray:
(http://i1375.photobucket.com/albums/ag467/rdawlud/vray_zpst3okfxpd.jpg) (http://s1375.photobucket.com/user/rdawlud/media/vray_zpst3okfxpd.jpg.html)
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: maru on 2015-12-04, 17:48:50: Sorry, but could you be more specific? What is the difference you are seeking? Can you provide some other examples?

Maybe the difference is different phase of motion? Below are two examples.
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: pokoy on 2015-12-04, 18:31:09: If the motion is linear for the whole range of motion blur/shutter speed range then it definitely looks wrong. Did you try to increase the segments in the motion blur settings? If this doesn't work, try slowing down the motion and compensate with a slower shutter. If this looks better than you may have hit a motion blur limitation which can occur with *very* fast moving objects.
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: Ludvik Koutny on 2015-12-04, 18:33:28: Motion blur in Corona should behave nearly same as in V-Ray. This comparison does not say much. You should compare exactly same scene from exactly same camera with very similar materials and lighting, and only then come to some conclusions.
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: Nekrobul on 2015-12-04, 18:58:27: For starters if we are speaking of realistic look, then you should rig the car and set the tyres turning.

And for achiving better realism try to setup lithing using photografic exposure+RL parametrs for example if it is going to be Daylight exterior shot you shoulf use something like ISO 100 Apeture 4-5.6 Shutter 125 or above.
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: DarcTheo on 2015-12-04, 19:08:29: Quote from: Rawalanche on 2015-12-04, 18:33:28
This comparison does not say much. You should compare exactly same scene from exactly same camera with very similar materials and lighting, and only then come to some conclusions.

This.
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: rdawlud on 2015-12-08, 18:03:59: Hello,
I prepared better images.
vray:
(http://i1375.photobucket.com/albums/ag467/rdawlud/vray_zpsqhgn2rvq.jpg) (http://s1375.photobucket.com/user/rdawlud/media/vray_zpsqhgn2rvq.jpg.html)
(http://i1375.photobucket.com/albums/ag467/rdawlud/vray2_zpsjvp2pvaw.jpg) (http://s1375.photobucket.com/user/rdawlud/media/vray2_zpsjvp2pvaw.jpg.html)

corona:
(http://i1375.photobucket.com/albums/ag467/rdawlud/corona_zps3epdgkj5.jpg) (http://s1375.photobucket.com/user/rdawlud/media/corona_zps3epdgkj5.jpg.html)
(http://i1375.photobucket.com/albums/ag467/rdawlud/corona2_zpsr7pxng4t.jpg) (http://s1375.photobucket.com/user/rdawlud/media/corona2_zpsr7pxng4t.jpg.html)

my problem:
(http://i1375.photobucket.com/albums/ag467/rdawlud/corona_problem_zpsncwwhyis.jpg) (http://s1375.photobucket.com/user/rdawlud/media/corona_problem_zpsncwwhyis.jpg.html)

I hope here I explained this better. In vray car edges dissapeard, everything is blurred. I can't see car lines, on the left and on the right. In corona, even in bigger blur left side of the car is more transparent, right side is blurred but I still see all car edges. Also wheels have some "smudge" effect in corona, and in vray everything is more "moved".
Settings are the same in both renders. In my opinion vray effect is a lot better for me in this and I want to achieve something similar in corona.

In corona I was playing with shutter spped ( car is more blurred but corona is blurring this in this way I don't like and also I tried different settings with transform and geometry segments but it didn't work.

Any suggestions?

Greetings,
Rafal
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: Ondra on 2015-12-08, 18:09:14: Maru's explanation is the most plausible one. The difference when compared with vray could be caused by Corona having different shutter offset by default.

Ondra
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: romullus on 2015-12-08, 19:52:38: Something must be wrong on your side, because Corona's MB works perfect for me. If you want to render MB on first frame, you have to either set keyframes before begining of timeline or simply set out of range types in curve editor. And as it was mentioned already, give some spinning to your wheels, otherwise it will look fake.
Title: Re: motion blur problem. I want to achieve blur like in vray but I can't.
Post by: maru on 2015-12-09, 11:47:48: Yup - which frame are you rendering? At which frame does the motion start? What tangents are you using for the keyframes? There are many factors. :)