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lalabell
06-07-2010, 01:34 PM
actually, it's not mine but someone else's question.
I tried to render an oncclusion passe of a scene, in my scene, there is only a little house modeling and a low cylinder to have a base, adding a custom camera which move around my litle house during 10 seconds
and I wanted to render that small animation with a very old PC ( I bought 5 years ago) with the configuration : pentium 4 3ghz, 1gb ram, xp pro 2002, graphic card radeon x1300/1550 series
and it took 2 days to render 10 seconds.
so the question is
do you think it's normal ? because that person won't stop telling me it's my problem and not the PC slow/old performance.
I use Maya 2010 if you want to know
thank you for your reply

Kanga
06-07-2010, 02:30 PM
I use Maya 2010 if you want to know
thank you for your reply
Why would we want to know that you are using Maya? What, so we can put this post in the right forum?
Render settings are vast and not the easiest things to set properly. Also there are a couple of different types of render engines. There are so many settings that you could have set too high, or incorrectly.

You dont say what engine you are using.
What resolution you are rendering at.
What frame rate.

Its a kind of a weird post actually.

lalabell
06-07-2010, 02:40 PM
oh, yeah, I totally forgot about that, sorry
I use mental ray in Maya for render
and I want to make a HD version, so it's 720x1280 px 24fps
file output is tga
I don't put any change in the render settings other than that
and I put Maya in the bottom is just for performance purpose, nothing specially with Maya, because it's almost the latest version, in comparison with my old PC, I think it's must consume a lot of time than if I use Maya 5.5 per example.

Sorath
06-07-2010, 02:54 PM
that kanda post is kinda weird..

lalabell - what matters to know is the samples you've used and a proper answer with suggestions how you could optimize - but hey - it's cg-talk
Occlusion is kinda slow also on modern machines - if you want to have it completely smooth - I know people using occlusion with more than 128 rays.
if you're fine you can use 32 rays and try with jitter off and or reuse-sampling aka sample lock on.
make sure to set your raytrace settings to 0, 0, 0 - but leave it on.

a proper solution to slow rendering occlusion would be the baking of it.
you can try baking it under lighting/shading - with the mentalray batch baker.
You need proper uv's for that and it can be quiet some pain getting the results.
otherwise you can try with x-normals importing the exported obj geometry and generating occlusion there. quiet fast but looks shitty.

I'd go for baking with batch bake and then photoshoping until it is fine.

I'm happy to hear other solutions.

lalabell
06-07-2010, 03:06 PM
thank you for you suggestion
I followed a tutorial
http://www.game-artist.net/forums/spotlight-articles/1317-tutorial-ambient-occlusion-maya-alchemist101.html
so I have 256 samples and I put 10 10 20 for raytracing settings
it's my first try at occlusion so :p
you see, I put super noob in the title
and I know for sure there are a lot of things to optimize but that person just won't stop bugging me to ask professionals the question " is that normal, bla bla bla " ...
thank you for your suggestion, I'll redo it to see :)

Kanga
06-07-2010, 03:15 PM
that kanda post is kinda weird..
Not really.
The application is important and the engine is important and the end result is important.
Default settings in an engine are never ideal because every job is different. mymentalray.com forums are the best place to solve your render problems with that engine. Your settings can be the difference between it working or not.

Sorath
06-08-2010, 08:58 AM
..well that's why he wrotes that he uses maya.
he would have written if it was vray or 3dlight or finalrender or whatever.
so it can only be mentalray.
but yeah, as we see raytrace settings and occ rays are way off.. so set your occ rays to 32 and raytrace to 0,0,0 kanga. there are a lot of other things you could optimize in terms of kd-tree optimizing with bsp in mr. and other performance stuff. best thing is to get a bit more familiar with mr. and look out for tutorials on renderoptimization.

btw. with 32 occ rays you might get heavy flickering - try increasing the rays until it is gone - by 64, 128 ...
set the spread low (0.7) and the distance according to your scene size. I use 12 for default grid sized models.

best
Bastian

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