Hunting down long rendertimes??

[k-arts]

Hi,

we are having major issues right now with long rendertimes and i am trying to find the reason for it. Are there any settings that usually tend to produce long rendertimes without knowing it. I tried a few things. I went to the object itself and right clikced it to get the vrayproperties and turned off all the stuff i dont need. I tried to keep the subdevision of my reflections around 10. I found a vray material with a subd of 50 in refraction but i guess since the color is pure black it wont matter. GI is turned on with 2 vraylights and one omni no shadows turned on.

Following settings are also enabled:

Globalswitches:

default lights unchecked

Adaptive QMC min2 max4
AntialFilter: Cubic

IRMAP High Animation Preset
HSph 30
Interp. 20

InterpType: Least squares Multipass checked
samplookup: density basedRandomized checked

IndirIllu

On checked
GI Caustics Reflective checked

Primary mp 1 GI engine Irradiance map
Secondary mp 0,75 GI engine Quasi-Monte Carlo

QMC GI
subdiv: 6 secbounce:2

QMC Sampler:
Adaptive amount: 0,85 Min Samples:8
Noise threshold: 0,005 GlobSubMul:1
TimeIndep. checked

G-Buffer ColorMapping
Linear multiply
dark 1
bright 1
Clamp checked
Affect Bkgr checked


The scene includes a car with floor set to renderable and visible to camera turned off. As soon as we get too close to the car we ger render times as much as 9 hours a frame which just doesnt work. The materials we used are not too fancy. Mainly reflections with a few falloffs and refl. glossiness set to 0.8.

So far so good any help is greatly appriciated.

Cheers

ralf

[joconnell]

Use light cache for the secondaries anyway and use 1, 4 for the aa settings. Are many things animating in your scene or is it a camera flythrough?

[k-arts]

Just camera

Its just a camera animation. The car itself stays at the sme position. Are you thinking of precalc the irmap? I would do it then as incremental irmap save. What would u reckon?

thx for the help

ralf

[panthon]

I would definitely precalculate the solution! It will be much much faster!

Besides that, u can check store with irradiance map on the vraylights, it will speed it up a lot. If u do so, try not to use low GI settings, because its fairly proportional.

[k-arts]

precal and lowering the resolution?

Would you recommend to lower the resolution for the precal. Lets say i render the final image with 1280x1080 and would now set the resolution 960x810 or even lower would this be ok or would this lead to unwanted artifacts of any kind?


and precal and save the lightcache is it the same as saving the the irmap? how would you set it up?

cheers ralf

[Candelero]

Re: precal and lowering the resolution?

Would you recommend to lower the resolution for the precal. Lets say i render the final image with 1280x1080 and would now set the resolution 960x810 or even lower would this be ok or would this lead to unwanted artifacts of any kind?


and precal and save the lightcache is it the same as saving the the irmap? how would you set it up?

cheers ralf

That should work, yes.
You can do some frame-test-renders to see it that comes good enough for you.

Best regards,
nikki Candelero

[joconnell]

Heya Ralf,

Use light cache in flythrough mode set to auto save and switch to saved file, and irradiance map set to multiframe incremental and again auto save / switch to saved file. Depending on how quick your animation goes, you turn on fdont render final image and then render every 10th, 50th, or 100th frame depending on how fast the camera moves through the scene.

Can you upload a preview of the animation so we can give you a better idea of how many frames you'll need to precalc?

[k-arts]

Flythrough it is..

its a 25 frames animation so i reckon its way too fast for every 5th frame so i do every frame. thats also the reason of being so frustrated with the rendering time or lucky. depends from which side you are observing it just to all let you know the rendering time is now 57min which is awsome without precal, so rock on. I just hvae to look if it lines up with the already rendered frames to see if the light and colors match, wish me luck guys

cheers ralf

[k-arts]

Render time is down...but

the time is now down to 10 min with precalc lc and ir which is great. However the image with the lc seems darker then the one with qmc gi engine. does anyone know why? might selecting "use light cache for glossy rays" do the trick? or any other setting?

cheers ralf