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Train track 'resolution' - Printable Version

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Train track 'resolution' - Ronald Vallenduuk - 2015-07-07

After I finished 53400, the PF curved track, I started on the PF points (53404 & 53407). As these are going to be big files I wondered if I could reduce the file size. The most obvious way would be to make the steps or sections in the curved rails bigger so as an experiment I changed 53400 from roughly 10LDU sections to 20LDU sections. That took 42% off the combined file sizes of the sub files. I then viewed both versions in LDView and didn't spot a difference:
https://www.flickr.com/photos/duq/19510895741/in/dateposted/
So what do you think? Going forward, use 10LDU or 20LDU 'resolution' for curved track parts?


Re: Train track 'resolution' - Philippe Hurbain - 2015-07-12

Seeing the results I'd favor the 20ldu version (or even coarser?) Don't forget also that even if file size saving is nice, key point is overall triangle number!


Re: Train track 'resolution' - Max Martin Richter - 2015-07-12

I would prefer, if you could upload both version to the forum, that I/we can compare it from all sides.

/Max


Re: Train track 'resolution' - Ronald Vallenduuk - 2015-07-12

Here you go, both versions to compare. The main part is the same for both, the difference is in the subfiles.


Re: Train track 'resolution' - Ronald Vallenduuk - 2015-07-12

They kinda go hand in hand though ;-)
The file size reduction is because the number of quads in the rails is cut in half. The number of lines of course has also gone down.


Re: Train track 'resolution' - Max Martin Richter - 2015-07-12

Thanks,
I think, after diving deep into the part, I would vote for using the 20 LDU version. :-)

/Max


Re: Train track 'resolution' - Roland Melkert - 2015-07-12

I don't think the difference is noticeable/relevant in programs doing normal smoothing (like LDView) but it might be noticeable in e.g. 1 on 1 POVRay exports etc.


Re: Train track 'resolution' - Magnus Forsberg - 2015-07-12

What would be the next logical resolution?
8 / 16 / 48 / ?

10ldu-part gives a resolution of 512 sections for a full circle
20ldu-part gives a resolution of 256 sections for a full circle

Wouldn't 192 be a better choise?
8 / 16 / 48 / 192


Re: Train track 'resolution' - Ronald Vallenduuk - 2015-07-13

I don't understand what you mean...
Where does 8/16/48 come from? Yes, 192 would be the next number in that sequence and 960 would be next, but I don't see what that means for these parts.
The 10LDU or 20LDU are coming from how the curved part and the sub-parts are constructed, not from how many sections there are in a full circle.


Re: Train track 'resolution' - Magnus Forsberg - 2015-07-13

I'm thinking of primitive substitution here. 8 /16 / 48 is our current choises of primitives, low/normal/high resolution.
What would be the next one? very hi-res? 96 or 192? Os something else?

I can see, and understand why 256, or 512, is the best choise here, based on the design of the part.
This part is 1/16th of a full circle. Placed on four sleepers/ties. 4x16=64. 64x4=256 or 64x8=512

Since this part/subpart is made without using primitives, it doesn't matter.
Maybe I got "sidetracked", playing around with the numbers here, trying to understand it. ;-)

But the question is somewhat interesting. How do different software work with primitive substitution?
LDView seams to 'recalculate' rather than 'substitute' primitives.