few questions regrading animation with vray

[chow choppe]

hi

 

justa a few questions that popped while working on my first animation with vray

 

1.) i made shrubs using scattering a leaf over a box depicting hedge.(BRIANS technique) It increases the render time per frame to double. Whats the solution for this so that render time is not that high?

2.) will there be any difference in rendering time if i make these shrubs as proxy objects and then render? because i dont see any right now.

3.) when people over here say thatrender time per frame of 8- 10 minutes is normal are they including the time required to calculate the lightcache and irradiance n the beginning or its just the rendering time after using saved maps

4.)is there a way in which i can make an object visible only when its visible in the camera view that i am rendering? will this speed up things.

 

 

Thanks

[chow choppe]

no answers?

[BrianKitts]

1. your rendertime (10mins) isn't high in my opinion

 

2. proxies will slow it down if it has to load and unload alot of geometry, if you have enough memory not to proxy....then don't, you will save the time wasted swapping geometery in the computers memory.

 

3. no I don't count the irradiance, because it should almost always be precalculated. Precalc your irradiance to save on render time, and create an even GI solution throughout the animation.

 

4. 10-12 is a great render time per frame IMO. What size are you rendering to? My last animation rendered @ 1440 px wide, took an hour to generate the irradiance map for each of the 5 camera passes, and the average frame time was anywhere from 12 up to 20 minutes.

[chow choppe]

1. your rendertime (10mins) isn't high in my opinion

 

2. proxies will slow it down if it has to load and unload alot of geometry, if you have enough memory not to proxy....then don't, you will save the time wasted swapping geometery in the computers memory.

 

3. no I don't count the irradiance, because it should almost always be precalculated. Precalc your irradiance to save on render time, and create an even GI solution throughout the animation.

 

4. 10-12 is a great render time per frame IMO. What size are you rendering to? My last animation rendered @ 1440 px wide, took an hour to generate the irradiance map for each of the 5 camera passes, and the average frame time was anywhere from 12 up to 20 minutes.

 

 

 

Thanks Brian

 

2.)i think i will need proxies to speed up VPort display also

3.)my LC calculation for 600 frames took around 9 hrs to calculate. i have never understood one point i.e how calcualting irradiance before makes renderign faster and Gi even. isnt it like total render time will be same wheteher u calculate IR and LC at the time of render or precalculate it. i mean if an image has to go thru 3 process IR calculatuion , LC calculation and rendering the image then how does it affect if its done per frame or all at once in the beginning. i know i am wrong but just trying to understand the logic behind it

4.) i am rendering at 720X480 and there are lot of 3d and 2d trees in the scene. when i am rendering a single frame with single frame settings for both LC and IR i get a time of around 12 minutes for first frame. Will subsequent frames take less time?

 

Thanks

[BrianKitts]

yes, proxies will definitely speedup your viewport performance thats for sure, I was referring more to render time.

 

as for precalc, how many subdivisions are you using for your LC and make sure you are using it on flythrough mode, you don't calculate the LC like the IRR map. my LC at worst takes 40 mins for an animation pass

 

As for the Irr map, because you only calculate it on every nth frame the middle frames are a blend of the keypoints that the map was calculated from. If you do every frame unique on different machines you will get small differences between frames that will result in flickering, precalc is the solid option here.

 

have you been through this tut?

http://www.spot3d.com/vray/help/150R1/tutorials_imap2.htm

[kippu]

i am assuming hes gone through it and has used WORLD settings for LC in an exterior ..resulting in 9 hours

[aaron-cds]

Another way to cut down on render time is to turn off gi for the shrubs.

[chow choppe]

yes, proxies will definitely speedup your viewport performance thats for sure, I was referring more to render time.

 

as for precalc, how many subdivisions are you using for your LC and make sure you are using it on flythrough mode, you don't calculate the LC like the IRR map. my LC at worst takes 40 mins for an animation pass

 

As for the Irr map, because you only calculate it on every nth frame the middle frames are a blend of the keypoints that the map was calculated from. If you do every frame unique on different machines you will get small differences between frames that will result in flickering, precalc is the solid option here.

 

have you been through this tut?

http://www.spot3d.com/vray/help/150R1/tutorials_imap2.htm

 

 

I am using 1000 subdivisions

.02 size, passes 1 , prefilter on - 18 and nearest selected with i think 32 its value

 

iam using acreen for the LC and yes its o flythrough mode

 

When u r saying 40 minutes for an animation pass u r talking about how many number of frames?

 

Is 9 hrs an acceptable value?

[chow choppe]

Another way to cut down on render time is to turn off gi for the shrubs.

 

but that decreases light on them for that i need to add extra lights for just hose shrubs using the inckude/exclude feature o lights

[chow choppe]

i am assuming hes gone through it and has used WORLD settings for LC in an exterior ..resulting in 9 hours

 

resulting in 9 hrs mean i am doign it the wrong way . i think i am using screen and not world because i read that tutorial and from that tutorial

 

"For exterior scenes, it is recommended to use the Screen mode always."

[BrianKitts]

when you do lightcache on fly through you only render a single frame. because it's on flythrough mode it will calculate your LC for the entire path of the selected camera. Then switch to Nth framing to calculate your IRR map.

 

If your 9 hours is doing LC render for multiple frames then that is your error.

 

In my experience vray can handle geometry, it's not going to save you much time turning off GI on an object because of heavy geometry. It's really materials that kill a render time. So if you had a glass shrub..... yeah I'd turn off the GI, but otherwise I would check how much time advantage its really giving you versus quality and appearance.

[chow choppe]

no my LC is calculating fine f or 600 frame

it shows me as a single image full of dot and i can see the hazy image behind it.

but after that it calculates prepass for all the frames

is that normal

 

my 9 hrs is for calculating LC for 600 frames

[BrianKitts]

my 9 hrs is for calculating LC for 600 frames

 

yeah... just do one, that's all you need.

 

if you notice from the tut, they up the subdivisions then just render one frame from the middle (#360)

 

1.24. Set the light cache Mode to Fly-through again.

 

1.25. To smooth out the light cache a little bit, increase the the Subdivs to 3300.

 

1.26. Change the Filter back to Nearest.

 

1.27. Render frame 360:

[chow choppe]

yeah... just do one, that's all you need.

 

if you notice from the tut, they up the subdivisions then just render one frame from the middle (#360)

 

1.24. Set the light cache Mode to Fly-through again.

 

1.25. To smooth out the light cache a little bit, increase the the Subdivs to 3300.

 

1.26. Change the Filter back to Nearest.

 

1.27. Render frame 360:

 

i think i am gettinga little confused here

 

"Do one means" i render one frame? why is that required?

[kippu]

in a flythrough LC mode .. if you render a SINGLE frame ....it will calculate LC for all the frames 0-600 in your case