Topic: Render times

[Simoni]

Am trying to render a scene with lots of lights, at 1080p one star render, it takes about 4 sec a frame, but at 1080p two star render it takes 28sec per frame, why the huge difference? only visible difference is one star is not anti aliased?
I cant seem to render the view from a distance (taking in the whole scene) at all, it just goes to white screen.
Maybe a dumb question but would Lumion 2 be 64 bit?

[Simoni]

Have now put all the interior lights on their own layer and turned them off, render times are now about 4 sec a frame for the external film, good.

[Morten]

To reduce render times, we recommend that you turn some of the distant lights in your scene into static lights (so that the shadows are not updated every frame).

All you need to do is to select the distant lights, and set the desired shadow map texture resolution:

Light Properties -> Shadow Cache -> 128/256/512

[stucki]

please insert static light 1024x1024 and static lights 2048x2048 !
it will still gain performance because it needs not to be updated, or ?

[Morten]

(Please post your request in the Wish List section, Stucki - otherwise it will disappear under the avalanche of posts in the General Discussion section )

[Simoni]

Thanks Morten, I am pretty sure all the lights are static lights, but theres maybe 50 of them, would this slow down the render hugely?
Maybe the lights were not the cause of the slowdown I have also turned off a load of seating objects.
I can understand the use of static lights, but when would you use a light that is updated every frame? Presumably moving lights, but being as the lights cant be attached to any moving object like a car, because objects cant be grouped in Lumion, when would you use a moving light on its own? Maybe an UFO or a shooting star?

[Morten]

The idea is that you would use a light with dynamic shadows if something that casts shadows is moving near the light (a car driving past a street light for example). Or if the light itself moves/rotates (stage lighting for concerts for example). Or if you need high-resolution shadows in certain areas (typically close-ups of interiors); lights with dynamic shadows use 2048x2048 pixels for the shadow texture whereas static lights obviously use one of the 3 low resolution options: 128x128/256x256/512x512.

I don't know if the render times you experienced were longer due to the lights in your scene or due to the seating objects though - only another test would reveal that.

[Simoni]

Hi Morten
have now turned all the heavy seating off, and all the lights on, about 60 lights, render times have gone up to 80 sec per frame at 1080p 3star, turned light layer off as well, and its now down to 6 sec per frame. That doesn't sound logical? If there are no lighting recalculations every frame, then the lights should not change the render times? Maybe some of those lights are set to dynamic, will have to work through them.

[Morten]

Hi Simon, thanks for posting your results.

Is this how you converted all the lights to using 512x512 pixel shadow caches:

1) Select one of the lights -> Light Properties
2) Zoom out and CTRL + Rectangular select all the lights in your scene
3) Light Properties -> Shadow cache -> 512

[Simoni]

Hi Morten
have now used this method to turn all the lights to static ones with a 512 texture map, and yes the render times have now become respectable.Thanks.
One thought, rather than have the default setting for lights to be dynamic ie very processor heavy, maybe it would be better to have the default setting at say a static 512. This way you would avoid the situation of making the scene unusable after adding maybe only 10 default lights?

[stucki]

good idea Simoni !!

[Morten]

One thought, rather than have the default setting for lights to be dynamic ie very processor heavy, maybe it would be better to have the default setting at say a static 512. This way you would avoid the situation of making the scene unusable after adding maybe only 10 default lights?

(Would you mind posting this suggestion in the Wish List section, so we're sure the developers will have a record of it? Otherwise, your idea will most likely get lost among all the other posts here in the General Discussion section)