IR+LC: Use camera path ?

[bernhard]

We do have the option to check "use camera path" for the IR as well as for the LC calculation.
If you do have an animation of 100 frames, you calculate for every frame the entire camera path ?

And do you usually use both of them together for one animation ?

thx for all your comments about this.

[Zdravko]

If you do have an animation of 100 frames, you calculate for every frame the entire camera path ?

This will depend on the animation that you are rendering. In example if you render fly-through animation you don't need to calculate IRR map for every frame. You can just render the first one and "use camera path" option will force the IRR map to gather information for the entire camera path in a single frame. In another hand if you want to render animation with moving objects you need to set the mode to Single frame or Animation (prepass), enable animation and the IRR map will calculate the entire camera path for every frame. This will help to reduce flickering in the output because the samples set on static geometry will not change.

And do you usually use both of them together for one animation ?

Yes, you can use "use camera path" option for both LC and IRR map in the above cases.

[bernhard]

You wrote: "enable animation and the IRR map will calculate the entire camera path for every frame"...
In that case, you also have checked "use camera path" for the IR as well as for the LC ?

Ok, just to make sure I did not misunderstand you. I want to talk about an animation with moving objects.

Let's say I render an animation with moving objects in "Single" mode, do I have to check "use camera path" to reduce and avoid flicker issues ?

Or is the "use camera path" option only meant to use for the Animation (Prepass) mode ?
Can the prepass mode sent to different machines on the farm, or just to one ?
Or just for a fly-through mode with no moving objects ?

When do you use the "use camera path" option for IR and LC?

And yes, I would like to save and re-use both IR and LC for further renderings with moving objects, that's my goal.

To make it super easy and simple and to make sure we are on the same page, can you please let me know the entire process when using the IR Animation Prepass mode with LC ..... and again, unclear is still if I can use "use camera path" also just in "single" mode.

Step 1
Step 2
Step 3
Etc.


Thx a lot

[Zdravko]

You wrote: "enable animation and the IRR map will calculate the entire camera path for every frame"...
In that case, you also have checked "use camera path" for the IR as well as for the LC ?

Yes, in this case where you have moving objects in the scene. You enable the "use camera path" option for both LC and the Irradiance map.

Let's say I render an animation with moving objects in "Single" mode, do I have to check "use camera path" to reduce and avoid flicker issues ?

Yes, you can either use Single frame or Animation (prepass) with enabled "use camera path" option when rendering animation with moving objects in order to reduce flickering.

Can the prepass mode sent to different machines on the farm, or just to one ?

You can calculate the Animation (prepass) mode on more than one machine by using DR.

Or just for a fly-through mode with no moving objects ?

You don't need to use the option with the LC fly-through mode.

When do you use the "use camera path" option for IR and LC?

Here you can find more information on the option for IRR and LC usage: http://www.spot3d.com/vray/help/200R...ap.htm#options
http://www.spot3d.com/vray/help/200R...tm#calculation

To make it super easy and simple and to make sure we are on the same page, can you please let me know the entire process when using the IR Animation Prepass mode with LC ..... and again, unclear is still if I can use "use camera path" also just in "single" mode.

Here is the exact step by step tutorial on how to render animation with moving objects: http://www.spot3d.com/vray/help/200R...ials_anim2.htm
(just note that in the first part "1. Generating the irradiance maps" you need to use Animation (prepass) instead of Animation (rendering), we will fix the error in the help)

[bernhard]

If you use "Single Mode" for
- both LC and IR Map
- both "use Camera path" checked

Can you actually also check "Auto Save" for both LC and IR map and reuse the saved files for additional renderings ?
I actually never saved these files when using "Single" mode - just curios.

If that's the case (that you can auto save both files in single mode) why should you ever run an "Animation Prepass" ?

[bernhard]

Following the mentioned above..... if I compare then "Single Mode" vs. "Animation Prepass" I can't actually see any difference.

[Zdravko]

Can you actually also check "Auto Save" for both LC and IR map and reuse the saved files for additional renderings ?

Yes, you can save those maps and reused them after.

If that's the case (that you can auto save both files in single mode) why should you ever run an "Animation Prepass" ?

The difference is that with Animation (prepass) mode one can interpolate several adjacent frame IRR maps to reduce flickering in the animation. The amount of the interpolated IRR maps is determined by the Interp. frames value.

[bernhard]

That means, that if you want to be on the safe side and making sure you don't have any flickering - The Animation (Prepass) mode is the better choice to go, right ?

If using "Single Mode" - and you want to save for each frame the IR map and the LC file.... do you have to check switch to saved map ?
I was running one test, had Auto Save on, but there was only one IR map saved, and only one LC file....
Looks like it basically overwrites the IR map and the LC that was calculated from the last image. Or do I miss something here ?

I was running a test with a simple scene .. and it looks like that using the Animation Prepass mode takes three times longer than using the Single mode.
Output doesn't really look different, but three times longer is really scary....

Your thoughts on this ?

[Zdravko]

That means, that if you want to be on the safe side and making sure you don't have any flickering - The Animation (Prepass) mode is the better choice to go, right ?

Yes, that is correct.

If using "Single Mode" - and you want to save for each frame the IR map and the LC file.... do you have to check switch to saved map ?
I was running one test, had Auto Save on, but there was only one IR map saved, and only one LC file....

Switch to saved map will automatically set the irradiance map mode to From file and set the already calculated map. Please note that Single mode will not save separate files when you have animation. It will override the IRR map for every frame.
It will be best to use Animation (prepass) if you want to save IRR map per frame.

I was running a test with a simple scene .. and it looks like that using the Animation Prepass mode takes three times longer than using the Single mode.
Output doesn't really look different, but three times longer is really scary....

As I mentioned before the Single mode does not interpolate IRR maps therefore it will render faster. But the Animation (prepass) will produce less flickering. So in your case if you get a flicker-free output with the Single frame mode you can use it instead but you will not be able to save a separate IRR map for each frame.
Furthermore decreasing the Interpolation frames will reduce the calculation time.

[bernhard]

Furthermore decreasing the Interpolation frames will reduce the calculation time.

I was running the test with just 2 frames Interpolation - also, decreasing the render time you mention.. this can only decrease render time in the final render... but the frame interpolation has no effect on the render-time when doing the Animation Prepass itself, right ?
Because the Prepass calculates anyways any single frame..... just want to double check that we are on the same page...


Also, when you render the final animation (Animation Rendering Mode) - do you still have to check "Use Camera Path" ?
Because you are loading anyways the IR map already from the files..... and I assume the IR Subdiv settings don't matter anyways anymore.. since all the data is already stored in the IR file... right ?

and finally:
for the Animation Prepass mode only --> does it work to calculate the Prepass with the half resolution of the final output ?
as instance: Full HD for the final render, Half HD for the Prepass

thank you so much

[Zdravko]

and it looks like that using the Animation Prepass mode takes three times longer

Could you please send us a scene for that issue?

but the frame interpolation has no effect on the render-time when doing the Animation Prepass itself, right ?

Yes, it only have an effect when Animation (rendering) is used.

when you render the final animation (Animation Rendering Mode) - do you still have to check "Use Camera Path" ?

No the "Use Camera Path" option will be used only during IRR map calculation.

for the Animation Prepass mode only --> does it work to calculate the Prepass with the half resolution of the final output ?

Yes, you can run some test before that, but basically one can calculate the IRR map on a half resolution and use it on a full one without any problems.

[bernhard]

1. HALF Res.. so your answer is basically YES, you can calculate the Animation Prepass with Half Res, right ?

Please let me again underline, that I am not talking about the min max rate inside the IR map... I am talking about the actual pixel resolution output.
Again, let's say a final render resolution would be 1280x720 ... you say you can calculate the IR map with 640x360... is this correct ?

for the final Animation Render Mode:
When using the Half Res for the Prepass.. do I have to set some extra attributes so Vray knows the IR Maps was calculated half res.
Or does it just work like that and I only set my final output to the final resolution ?
Couldn't find any additional info or documentation about that....


please find the simple test files here: max2011 64bit, Vray 2.20.03

Animation Prepass Mode:
http://www.mediafire.com/?ek5bghssu22m91h

Animation Rendering Mode:
http://www.mediafire.com/?l8z461w307by58b


Of course, I meant the total render process takes three times longer if you consider the prepass calculation of the LC+IR map and the "Use Camera Path" is turned on.

Single Mode Total Time including LC, IR and final render: aprox. 6 minutes
Prepass Mode Total Time including LC, IR and final render: aprox. 16 minutes

for both tests I had "Use Camera path on" for LC and IR.

Like you mentioned earlier, using the Prepass Mode takes longer because it interpolates the frames... but that the entire process takes three times longer is really strange.
Your thoughts about this ?


@Exterior - Interior:
Couldn't find any more info about this.. and I am not sure if my idea is correct.. but I guess for an open space render (exterior) Brute Force as secondary Bounce would be actually better as LC, right ?
What are your thoughts on this ?

Zdravko, what's your email address ?

IR Viewer:
Another issue I realized... I do have an IR map which seems to calculate correct, but when opening in the IR Viewer I can't select the major object and zoom in.
It's kind a clipping issue... anything I could change that ?

Here the IR Map - please let me know if you can view it:
http://www.mediafire.com/?19bz7sc7xc7oppv

[tashko.zashev]

Hi,

1. HALF Res.. so your answer is basically YES, you can calculate the Animation Prepass with Half Res, right ?

It is scene dependent, need to be tested first with couple of frames and if the result is acceptable, you can use this approach.
But basically this approach works fine in most of the cases.

About the resolution, you can either use lower output resolution for Irr prepass calculations or decrease the Min/Max rate values.
So if your image is looking good at High Ir map settings -3, 0, you can lower to -4,-1.

Thanks for sharing the files.

You are using very high value (80) for Interp. Samples, which will affect the render time a lot.
Actually V-Ray will use "400" samples to interpolate the irr maps (2 interp. frames = 5 frames x 80 samples = 400).
So i can advice you to lower it to the default value.