MTM2.com

I would like to know the possibilities and limitations related to the use of multiple backdrops in a track. I found this by Phin


and this by Winterkill


Can anybody help clarifying these statements to me?
Do multiple backdrops still have 16 faces forming a full circle?
More generally, what are the geometric requirement for a bin to be accepted as a backdrop?

What are the rules for displaying/blocking one rather than the other?
(As far as I understand, the size of the backdrop is irrelevant since MTM2 will resize it anyway).
More precisely, is it possible to force a specific backdrop to be displayed depending on the position?
(The idea would be to see a backdrop in the distance, then travel towards it (e.g. through a tunnel) and see the same view from a closer perspective)

What is the maximal number backdrops? 2?
Can Traxx handle multi-backdrop tracks?

> See winterkill's notes on it.

I probably meant this http://forum.mtm2.com/viewtopic.php?t=1832


> (refers to broken link)

Can't fix it if I don't know where to find it. But I suspect the link it was pointing to is the same as above.


> Do multiple backdrops still have 16 faces forming a full circle?

No. A backdrop is just a bin. It can be anything you want, but the applications are rare in which it can be anything useful except a full circle. Multi-drops or not.


> what are the geometric requirements for a bin to be accepted as a backdrop?

Geometry? None, really.

Bin file format is another story http://cownap.com/~mtmg/binedit/magic.html (or just use binedit v2)


> What are the rules for displaying/blocking one rather than the other?

http://forum.mtm2.com/viewtopic.php?t=1214


> the size of the backdrop is irrelevant since MTM2 will resize it anyway?

For the most part, that's true. Exceptions are hardly worth noting.


> is it possible to force a specific backdrop to be displayed depending on the position?

The position of the truck on the terrain? No.


> see a backdrop in the distance, then travel toward it (e.g. through a tunnel) and see the same view from a closer perspective

Backdrops are centered on the truck. The viewing distance is a constant.


> What is the maximum number backdrops? 2?

When you find out, please let us know. I've had up to five, I think.


> Can Traxx handle multi-backdrop tracks?

No. Hence the first link about editing sit files.



Note. The backdrop in alphaville uses five or six models, but there is only one backdrop (the animation control bin - which can be placed using traxx, but the models must be loaded manually).

Note. If I knew then, what I know now, godzilla vs bigfoot would have been far far different than it is currently. Probably, lol. I tried to do so much with that one but just didn't have the know how at the time. The aim was to create a truly 3d backdrop. It would be a snap to do today. But I could only get so close back then =(

Phineus, who has done amzing stuff in this field, posted while I was composing offline, so please excuse the overlap.


>> Do multiple backdrops still have 16 faces forming a full circle?

Not necessarily. See next comment...

>> More generally, what are the geometric requirement for a bin to be accepted as a backdrop?

I have 12 sided and 8 sided ones. "<a href=http://mtm2.com/~trackville/pics/12sided.jpg>This</a>" is a twelve-sided one, "<a href=http://mtm2.com/~trackville/pics/8sided.jpg>this</a>" is an eight-sided one, with four vertical tiers (like four backdrops stacked) and uses14 large textures and "<a href=http://mtm2.com/~trackville/pics/8sidedx2.jpg>this</a>" one is eight-sided too, the bright green vegetation at the bottom is actually a second backdrop smaller than the first, physically inserted near the base of the tree portion (it's all a single bin). All of them look great, but the more sides the better I suppose. Zoon Kitchen and few other are just big cubes. There are no requirements other than a magic number.


>> What are the rules for displaying/blocking one rather than the other?

Edit: see Phin's note


>> (As far as I understand, the size of the backdrop is irrelevant since MTM2 will resize it anyway).

To some degree, yes.

I wrote this paragraph back in 2000: "As for the automatic stretching thing you mentioned, it seems that is based the on the largest dimension of the backdrop. In playing with an idea for the straight track expo I elongated a standard backdrop to about 2000 feet on one axis, it did look "long" in the game but the sides cut into the terrain in a bad way."

I can't really explain that text, but I will say it did offer a stretched out perspective on one axis. I can also remember setting a couple of animated bins as secondary backdrops, such as a single offset object orbiting the terrain, creating a huge fly-by effect based on the speed of the animation (aircraft, meteor, etc.), I also made a cage-like thing that simple rotated horizontally in from of the existing backdrop. I never tried experimenting after that - it would be neat to see someone try it all again.


>> More precisely, is it possible to force a specific backdrop to be displayed depending on the position?

If one backdrop is wider than another, they should both scale down in proprortion to one another.


>> What is the maximal number backdrops? 2?

I don't know

>> Can Traxx handle multi-backdrop tracks?

No.

To make a functional backdrop you can make a bin from scratch, when complete just select all faces and set their face type to mtm1 transparency and set the group magic number to "-2147483648", or just "save as backdrop" with the amazing new BinEdit: http://binedit.com


edit: the "broken link" is to an ancient mtmbbs discussion, which i suspect my old text quoted above is from. No loss.

Show off, lol.



I remember most of that. By the way, I had bigger plans for alphaville but ran out of time. I'll have to pick it back up again for a future project.


One more note. In most cases, you don't need multiple backdrops. Have a look at darkstar in binedit to see how simply you can combine models and ideas into a single working backdrop.



Lastly, thanks for the reminder about BE2. Old habits die hard. I completely forgot saving as backdrop is a one shot deal now.

hehe

Thanks a lot guys
Since the backdrop pundits are hooked on-line, I may as well bother them with three more questions...
I could think of a big mountain with a 3D part protruding inside the basic circle to give a more 3-dimensional impression. Any technical objections?
I suppose that's how the eight-sided vegetation example was made. What is the advantage (beside preventing the use of Traxx, lol) of this method over making a single bin with more complex shape?

Are there implications regarding framerates?

>> <i>Any technical objections?</i>

No objections Sir Alces. If it's high enough above the horizon it should work fine, bearing in mind that things in the backdrop can seem very large (only through experimentation can you understand most of this, so experiment!).


>> I suppose that's how the eight-sided vegetation example was made.

Actually no, it's a single bin, made as if two backdrops were merged, however it could have been done with two separate backdrops, if they had been offset vertically with binedit.


>> What is the advantage (beside preventing the use of Traxx, lol) of this method over making a single bin with more complex shape?

hehe, by the way, I've heard Traxx is being updated but I know nothing other than that. Phin could handle this question well I think, to expand on his Alphaville example and associated stuff, but I can say there is no advantage in cases where simple backdrops are being combined. The advantage is when special effects are desired, especially animations. I've never used multiple backdrops apart from the early experiments I mentioned, using animated bins. Note: I think there are examples of multiple backdrops in the stock mtm1 tracks.


>> Are there implications regarding framerates?

No special ones that I know of, just bear in mind that complexity is complexity (vertices/faces) and texture load is texture load - on top of everything in the track.


A note: The blue sky in mtm begins at a certain short distance above the horizon, below that is The Netherland, which extends beneath the whole of the mtm world, this netherland must be covered by some kind of backdrop or else it causes the visual glitch often referred to as the hall of mirrors effect, or, perhaps as "OOPS". Backdrop makers need to bear in mind that horizon threshhold line when making custom backdrops, lest they freak out the peoples of mtm land.

Another thing to note is that enclosed backdrops (darkstar, kitchen, etc.) must be tall enough or else the top of the backdrop will cut into the tallest terrain when the truck is at the lowest altitudes. I learned this when making "<a href=http://mtm2.com/~trackville/pics/8sided.jpg>this</a>" backdrop, and I had to extend the top portion yet another tier (the 4th) in order to prevent the low ceiling effect. I do not have any necessary backdrop dimensions handy at the moment. Some day, perhaps, we should measure all the backdrops with binedit, noting the vertical offsets, and make a chart.

> If one backdrop is wider than another, they should both scale down in proportion to one another.
> What is the advantage of this method over making a single bin with more complex shape?

For godzilla v bigfoot, I had an extremely hard time getting the correct 'scenery' to display in front. If you look at that backdrop, it's actually three normal backdrops combined into one model. I am assuming, because I haven't tried it, but based on my experiment (link above) multiple backdrops "should" render each backdrop in the correct order - provided animated textures don't over-ride the defaults. Whereas, merged backdrops "may" not behave as anticipated. But this needs empirical confirmation. However, in the context of simple two teir static models, then there is no advantage that I can see.

Something to consider. When remaking the basic track layout (of GvB) so it would function in evo, it was necessary to remake the backdrop. For that, I mapped the entire thing to just one new texture. The lesson being, "most" things can be done with one backdrop. And they can usually be done more efficiently. So, the rule of thumb becomes, if you don't need multiple backdrops, don't use them.

> we should measure all the backdrops with binedit, noting the vertical offsets, and make a chart.

Since backdrops are resized more or less proportionately, anything with a tall-ish profile should work fine. Special applications will require a certain amount of trial and error no matter what the charts would say.