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Mental Ray / Final Gather / Buckets problem


Ras
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Hi Everyone

 

I am teaching a Viz Class at my former school and have run into this problem that I´m unable to solve.

 

Whenever I use final Gather on an interior view I tend to get problems with the buckets showing up in the final rendering. I´ve definately tried upping the FG samples but it doesn´t really help.

 

My colleague Allan (AKA "Architect" in here) posted in the Max forum yesterday but we are working on Viz at the school so I thought I´d post here and show an updated piccy.

 

we were trying to not use too many lights in the scenes for educational reasons but now we have conformed to the need of using area lights instead of just a skyligt.

 

I´ve uploaded a revised scene and rendering to show the problem. I´d really appreciate your advice on this.

This is a project of one of the students. It has been particularly hard to get around because of the very few windows in the room.

 

Thank you very much

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Your hardware migh be reponsible for the problem. I just downloaded your attached file and rendered in on my computer. It works just perfectly fine.

 

( i only reduce the number of photon to 200 and click preview in FG in order to save time).

Definitely the problem is not because Camera Clipping

 

AUVN

(nice space and very clean model)

 

 

how can I upload image on the thread????

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http://www.cgarchitect.com/vb/showpost.php?p=45285&postcount=7

 

( i only reduce the number of photon to 200 and click preview in FG in order to save time).

Definitely the problem is not because Camera Clipping

 

how can I upload image on the thread????

 

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Hi guys

 

Great advice! Wouldn´t have thought of it if you hadn´t pointed it out. Thank you.

 

What do you do if hiding part of the geometry is out of the question? I know that its easy to detach parts of a mesh to an individual object and hide it from the camera - but is there another way?

 

Again - thank you very much!

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Yeah - but how does FG work - does it calcultate a solution for a room even if it is hidden from the camera? I mean if I don´t hide the wall that I want to near-clip in front of, then I don´t suppose MR calculates the light behind that wall?

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You can just try creating a camera without manual clipping and get it inside the room. It doesn't have to look pretty. Then do the final render from your clipped camera re-using the fg map. As far as I know, the fg map is view independent. It's just something you'll have to experiment with.

 

This is a known issue, but it's hard to say whether it is a bug with mr or the max camera - or whether it can even be resolved.

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Thanks a lot Fran - that cleared it up for me...

 

But it also imlplies that FG is calculated everywhere in the scene - like behind the camera?

Is it safe to assume then that once the FG map is calculated and saved it can be reused for a camera animation without further calculations - assuming that no lighting conditions are changed?

 

I haven´t really worked very much with animation. I know these are newbie questions but since I´m trying to help the students develop their skills, I better learn this...

 

How about the photons then - are they view independent also? Meaning - can I safely use the saved photonmap for an animation too?

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fg is camera dependent

photons are light dependent

 

so if you move the camera mray has to rebuild the FG solution

if you save the photon map you can re use it even if the camera changes position or is animated (if no objects or lights move or change in the animation)

 

the best thing for animations with mental ray would be to texturebake the scene, but you will need max 7 for that, max 6 and VIZ 2005 cannot texture bake mental ray

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  • 5 months later...

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