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AmigaNewTek
06-07-2011, 06:05 AM
Out of curiosity...

does the scene size matter for rendering time? Looking @ various tutorial (this one, for example: http://www.youtube.com/watch?v=04JO3eAs5Js) i noticed that all the scene related to land, alien planets, and so on... have terrain size in order of meters. I have always drawed terrain in order of KM or hundred of KM. Look @ minte 9:45 in the video i linked above. It's seems that the land size is about 40 meters. I've created a scene with a terrain of 800 KM. What's the best way to operate?

Thank you

moussepipi2000
06-07-2011, 06:16 AM
i think size matter especially if you use radiosity because of bouncing light and precision parameter.

I dont like model with HUGE scale because the scene become weird. OPEN GL dont show correctly. Rigging come crazy etc.

But to reply to your question. No, i dont think it change rendering time.

IMI
06-07-2011, 07:25 AM
Size does matter. :D
For one, for SSS materials it's going to matter. I'm not sure if the actual scene scaling makes much of a difference, but you at least have to know how big everything is relative to your units and grid.
I don't know if LW 10 has more "real world" lights or not, but scene scale would definitely matter if it does, and scene size would definitely matter if you use IES lights.
And if you want to export for a game engine it definitely matters.
Personally, I always model things in some real world scale and stick to it for everything in the scene. If using LW, I do it in LW units, and that way I also know how to re-scale it when exporting for a different app.
It's just a good practice to be in. I'm not entirely sure the extent to which it matters in LW, but it definitely matters in certain other 3D apps for all kinds of things from lighting to surfacing to simulations.
I've never done anything approaching kilometers in LW though, so it's hard to say what might change when you get to object scales that large. Considering LW has somethign of a reputation in modeling and rendering space scenes though, I would hope it can deal with very large scales in a realistic manner.

AmigaNewTek
06-07-2011, 07:40 AM
So should i use a terrain surface of 40 meters, 40km or 400 km?
Scaling after the object is created in Modeler could cause problems, as for the luxigons exact position replacement.
Assuming i want to render nebulas or galaxys (1 Mm size), the light bounces will generate slow rendering?

prometheus
06-08-2011, 12:34 AM
So should i use a terrain surface of 40 meters, 40km or 400 km?
Scaling after the object is created in Modeler could cause problems, as for the luxigons exact position replacement.
Assuming i want to render nebulas or galaxys (1 Mm size), the light bounces will generate slow rendering?

I belive Itīs best to model true to scale for almost everything, it will be helpful when you model and construct things to know that everything will fit as long as it is created in correct scale, it will also help in the aid of creating textures,procedurals as well as bitmaps.
Landscaping will probably benifith from this too, depends on what else you got in the scene...also if you use skytracer, ozone or ogo taiki for atmospheric...wich might need a proper scale to look realistic together.

Thereīs one exception thou, astronomical scales are so vast and hasnīt got that much else in the scene to reference to, so it would be more practical to use very large scales, but not necessary true scales.

Nebulas I did with volumetric lights where up to 4 km in size, and in order to have texture displacements working properly I had to increase displacement strenght by thousands, for 1m sizes ..that would be enough with default settings of 100%..so It would be insane to use real scale under those circumstances.

Michael

inkpen3d
06-08-2011, 02:57 AM
Thereīs one exception thou, astronomical scales are so vast and hasnīt got that much else in the scene to reference to, so it would be more practical to use very large scales, but not necessary true scales.

Ah, I beg to differ - actually there's two exceptions! :D

It's a similar situation when you're working at microscopic or molecular scales, which I do regularly - you have to scale up the physical size of models/scenes by a factor of roughly 1000, 1 000 000, or even 1 000 000 000 depending on the situation in order to have something that is usable in LightWave.

For example, the lipid bilayer forming the envelope of a typical living cell is about 5nm in thickness (i.e. 0.000 000 005 meters), so I'd scale this up by a factor of say 10 000 000 so that my LW model of the membrane is 0.05m (i.e. 5cm) thick. Anything penetrating or floating in the membrane (e.g. protein molecules) is likewise scaled by the same factor. Textures/lighting, particle systems, and so on, all behave nicely at these scales in LW.

Slightly OT, but I thought you might find this little interactive "The scale of the Universe" (http://www.newgrounds.com/portal/view/525347) graphic interesting - you can move a slider to zoom from the scale of us humans down to the sub-atomic, or right out to the scale of the whole universe (each jump in scale being a factor of 10).

Regards,
Peter

prometheus
06-08-2011, 04:28 AM
Ah, I beg to differ - actually there's two exceptions! :D

It's a similar situation when you're working at microscopic or molecular scales, which I do regularly - you have to scale up the physical size of models/scenes by a factor of roughly 1000, 1 000 000, or even 1 000 000 000 depending on the situation in order to have something that is usable in LightWave.

For example, the lipid bilayer forming the envelope of a typical living cell is about 5nm in thickness (i.e. 0.000 000 005 meters), so I'd scale this up by a factor of say 10 000 000 so that my LW model of the membrane is 0.05m (i.e. 5cm) thick. Anything penetrating or floating in the membrane (e.g. protein molecules) is likewise scaled by the same factor. Textures/lighting, particle systems, and so on, all behave nicely at these scales in LW.

Slightly OT, but I thought you might find this little interactive "The scale of the Universe" (http://www.newgrounds.com/portal/view/525347) graphic interesting - you can move a slider to zoom from the scale of us humans down to the sub-atomic, or right out to the scale of the whole universe (each jump in scale being a factor of 10).

Regards,
Peter

Lol..I donīt pay attention to such little detail, thatīs why I missed it:D
Im larger than that:jam:

Great link by the way, Itīs always nice to have perspective of things...Mindboggling it is.
Michael