need faster renders.. help

NiGMa · Post by **NiGMa** » Wed Apr 18, 2007 1:26 am

Hi guys, have a look at the settings for this scene, it rendered in 14hrs! I'm happy with the quality but not the time.

I rendered at 3600x2394 (300dpi A4)
AMD Opteron 4x1.8ghz 4GB RAM Win64

This is too long for this fast computer, help me find better settings or items that may make the scene slow. Its got Skylight shader as Texture Enviro, 1 Spot & 3 Area lights.

Thanks a heap!

NiGMa

Post by **jure** » Wed Apr 18, 2007 9:23 am

Hmm could you tell me which part of rendering was slowest? Antialiasing? Maybe transparency or reflections?
The settings look allright... You could try increasing spatial tolerance a bit (0.1 or 0.15) and upping prerender to 100%.

NiGMa · Post by **NiGMa** » Wed Apr 18, 2007 9:40 am

AA pass is by far the longest, I don't know whether transparency or reflection is slower... I know that plant added alot but I dont think its the only thing thats slow. I used to use progressive render for viewing but now I use scanline so i can see what slows it down. I should do render with no plants and see how that compares to 14hrs.

Also, I dont understand why AA needs 10-20 rays, maybe I should make that lower?

Post by **jure** » Wed Apr 18, 2007 9:47 am

AA does look pretty good in your render so yes you could try lower settings...

NiGMa · Post by **NiGMa** » Wed Apr 18, 2007 12:12 pm

Thanks for your consistant help Jure!

If I understand Kray correctly, increasing the photon count will improve the iradiance map and so allow me to lower the FG settings, which should get me lower render times but slightly increase the prerender calculation time.

Pavlov · Post by **Pavlov** » Wed Apr 18, 2007 12:23 pm

hi,
i'd try this, in alternative to Jure's suggestions:

- use less photons, something like 500000 is enough and raise N to 4000/5000. This should give you a cleaner irradiance so we can lower FG a bit.
- FG: use custom, and these vaules: 0.001 200 800, sp.tol 0.1, Angle tol. 30° or more (this can kill time a lot), ripoff paths (set them to 0)
- AA: use 0.001 - 5 - 30 to start, pixel filter box 0.5. If you raise this radius, you have better to use mitchell which is the slowest but gives best results, since times will become similar. Try also to raise edge abs and rel to 0.5. Make also a try with upsample 0, it will speed things, dunno about results.

Paolo

NiGMa · Post by **NiGMa** » Thu Apr 19, 2007 5:23 am

Thanks Paolo

I inputted ALL your settings and went for even lower rays for AA, I had it at 0.001 - 5 - 15, but it didn't turn out good. I was quicker, but I'm not sure because I didn't try it on the same angle and I also was trying at 50% res. Thanks for the tips though, i'll be playing with higher N numbers and Angle tol. 30%. I need paths=1 because I get light leaks in my scenes, walls + furniture.

I dont understand why pixel filters would change the render times, I thought it was just the way it combined the image at the end???

Pavlov · Post by **Pavlov** » Thu Apr 19, 2007 10:42 am

hi,
please post result so i can understand what is changing and how.. regarding filters, there are not "post" filters, but how pixels are resampled when doing AA. there's no post effect in Kray, at least not yet.
If you get leaks it can be bad geometry, can i give a look at your object ? having messed geometry can require higher setting and cause strange behaviors.

Paolo

awright · Post by **awright** » Wed Sep 19, 2007 1:02 pm

I think an image like this should be no longer than 15 minutes in your machine.

I did the 1.7 tutorial in 1920x1080 and was 2 1/2 minutes on a Xeon 8 core.

Post by **silverlw** » Wed Sep 19, 2007 1:21 pm

Nigma: Your settings look ok but there can be as paolo suggested something in your materials or geometry causing Kray to slow down so much. I also noticed that you used Octree 80 wich is tremendously high, could it ran out of mem? Use as low as needed usually 20/30. Also i would suggest to use adaptive Grid AA 4-8 with some oversampling if needed ( i dont think so in that resolution)
If the room aint bigger than 8mbytes packed i would like to look at it to easier pinpoint what's happening. Im reachable at crapmess@bredband.net

Captain Obvious · Post by **Captain Obvious** » Wed Sep 19, 2007 4:18 pm

A bit of retouch on that thing, just for fun...

Post by **silverlw** » Wed Sep 19, 2007 6:34 pm

Nice!

Pavlov · Post by **Pavlov** » Wed Sep 19, 2007 7:43 pm

try also rendering without AA and SAVE GI, then LOAD GI with gradient_flags 0+1; command and AA on (i have expanded on this several times here, look around). this will give you a huge boost for sure.

Paolo

NiGMa · Post by **NiGMa** » Thu Sep 20, 2007 2:06 am

Pavlov wrote:try also rendering without AA and SAVE GI, then LOAD GI with gradient_flags 0+1; command and AA on (i have expanded on this several times here, look around). this will give you a huge boost for sure.

Paolo

yeah, especially because the AA pass takes the longest on this scene.

I am working a new animation job at the moment so I have been experimenting with this.

question, whats with the name "gradient_flags 0+1" how is this related to what it does???

vashts · Post by **vashts** » Thu Sep 20, 2007 3:44 pm

if I remember correctly, the right command is gradients_flags 0+1; it enables FG sampling during prerender pass only.. however, don't worry about all those commands: in future it will be much more easy.

vashts

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