model size

[Boeufmironton]

hello all, i have a question for the modelers:

imagine a grid model

is it more light for ac to have a md3 plane model (2 faces) with png transparent skin or a great number of planes (something like 16x2x2 faces) to have crossing grid ?

in french:

imagine un grille

est-ce que c'est plus léger de faire une seule face avec un png transparent ou plein de faces pour chaque "barreau" ?

[ExodusS]

We can't use transparents .png for models IIRC.

[Cleaner]

@ ExoduSs, yes we can and we do.

Obviously the less polys you have the lighter your model will be...

On the end when it comes to graphic/visual effect it's day and night, this is why I have modified to 'full' models the grids/grates and the 'fence_chain_link' (this not yet committed to svn).

The thing is with planes only models is that the closer you get to the side of it the model tends to disappear, it's physically too thin to be seen.
My point is that single plane models should only be used as 'decals', something you stick against a structure, a wall, floor and so on.



Single plane model


Full 3D model



Please also note that nowadays in order to avoid the 'shoot through' issue we no longer use single plane models, even decals are made of 2 planes.

[D3M0NW0LF]

nice looking fence, can't wait to see it ingame :D

[Mr.Floppy]

Just for clearification.

In fact the engine does not support 'real' transparency (so far) like with coloured glass for example. Though it's possible to use alpha masked textures (.png), where pixels of a certain colour woun't be rendered.

______

Well, maybe not as offtopic as one might guess:

Cleaner, I see that you put shoot-through issues above poly count in general and that most of your latest models are rather high poly.

This makes me wonder whether the low-poly-guideline has been changed in any way? Or are there even some engine tweaks going to be revealed with v1.2, which will handle those amounts better?

[ExodusS]

In fact the engine does not support 'real' transparency (so far) like with coloured glass for example.

This is what I asked for a while ago, and Cleaner said it was not really possible, I though cause of that, .png were not usable on mapmodels. :P

[Cleaner]

Cleaner, I see that you put shoot-through issues above poly count in general

Yes and there's no problems with this at all.
That 'shoot-through' issue is real pain and unfortunately there is no escape, you have fully close the models and add a back-face to single plane models.
At the end of the day we're talking about merely just a few extra polys so yes anti shoot-through primes.

most of your latest models are rather high poly.
This makes me wonder whether the low-poly-guideline has been changed in any way? Or are there even some engine tweaks going to be revealed with v1.2, which will handle those amounts better?

Policy is still to keep polys as low as you possibly can, the thing is that sometimes you can't.
Only just a few of my latest models have a poly count above the average but I tested these models on the crappiest of my pc (the one that overheats as soon as I move the mouse).

[Mr.Floppy]

Don't get me wrong, Cleaner.

I do appreciate your work and I totally agree with you, even though I personally never really considered the shooting-through behaviour to be an issue, to be honest.

However, I guess I kind of startet to hope we don't have to be that strict on low-polyness anymore because of some miraculous engine enhancements you guys just haven't told us about yet. :P

[Bukz]

Single-pane mapmodels are abused a lot in the current version. Poor quality maps have adopted them to make super campy spots where only the camper can shoot through the model, anybody from a distance trying to shoot back will be doing so in vain. IMO it was a serious issue and I'm glad it (hopefully) will no longer be an issue in the future versions.

[PhaNtom]

So that ruins @camper maps?

[Bukz]

@PhaNtom: Not necessarily. But you won't be one-way shooting through any official mapmodels thanks to Cleaner's hard work. :)

[PhaNtom]

GOOD

[ExodusS]

IMO it was a serious issue and I'm glad it (hopefully) will no longer be an issue in the future versions.

If you want to really fix this "serious issue" you should start by fixing some engine bugs everyone can reproduce in editing mode, I know a single-plane mapmodel is really easy to use for new mappers, but it wouldn't take them more than 5 minutes to masterise other bugs like the heighfield bug as well.

Anyway, even if the mapmodel is not single-planed, you can still load a huge mapmodel (let's take the big radar console as exemple) and unclip it from the .cfg. Like that, players can go inside the model and they can shot/see trough it, not their opponents.

No offence but this issue is kinda endless, and I know 2 different ways to make this kind of walls without using a single mapmodel, I made a Youtube tutorial a while ago on how to reproduce one of the 2 ways. Good luck.

[Bukz]

Thats not really the point @ Exo, the models should be fully sealed anyways, even being able to see through them while others can't is a problem. Hence my "not necessarily" about it stopping one-way shooting altogether. Ofc there are heightfield glitches and stuff that still can be abused, if it were an easy fix I imagine eihrul or stef would have done it years ago.

[Mr.Floppy]

Good point, Bukz. How could I forgot about this way of exploitation.

In order to prevent that abuse of huge models, like exo pointet out, you could just switch off those model's backface-culling. I guess the extra load on rendering is worth it.

[ExodusS]

In order to prevent that abuse of huge models, like exo pointet out, you could just switch off those model's backface-culling. I guess the extra load on rendering is worth it.

It would be a mess for the modeller to do that, because fixing only huge mapmodels would not be enough, small mapmodels can be used for the same thing too (take the platform, if you are under it, and if your head is into it, you can see trough). So all mapmodels taller than the 2x2x2 box would need a fix, ~100+ models to fix. And the next release gonna allow the autodownload/package stuffs, all unofficial models will enter with ease in the game.

[Cleaner]

Frankly, just for the sake of avoiding all this nonsense and keep rendering free of extra strain I wouldn't mind taking care of that backface-culling on already available models and making it a 'must have' rule on AKIMBO for forthcoming modellers material prior Auto-download enable.

It's a pain in the neck for sure but I think it's really worth the hassle.

As for official models I had to go through again to fix some other things anyhow.

[PhaNtom]

Did you fix the back of the signs too?

[Cleaner]

Did you fix the back of the signs too?

We're no longer talking about 'backs' here but about 'inners', 'backs' have been fixed quite a while ago now.

[PhaNtom]

Ah ok, great

[Mr.Floppy]

Backface-culling isn't done with modelling, some coder (lucas?) has to get his fingers on this. It's an openGL/DX feature which, at least on DX, can be set for each entity separatly. Though, it could just be set for all models except the player and hud models if things should kept simple, in our case.

You pretty much just pass the info whether or not backfaces should be culled to the graphics card. I guess it's merely a single line of code at the loading function where the particular gl flag gets set.

However, I'm quite certain some simple algorythm which would leave out very small or flat models according its bounding box's size wouldn't be such a bad idea. I have models like signs or those screw and cigarette in mind actually.

[Luc@s]

Backface-culling isn't done with modelling, some coder (lucas?) has to get his fingers on this. It's an openGL/DX feature which, at least on DX, can be set for each entity separatly. Though, it could just be set for all models except the player and hud models if things should kept simple, in our case.

You pretty much just pass the info whether or not backfaces should be culled to the graphics card. I guess it's merely a single line of code at the loading function where the particular gl flag gets set.

However, I'm quite certain some simple algorythm which would leave out very small or flat models according its bounding box's size wouldn't be such a bad idea. I have models like signs or those screw and cigarette in mind actually.

Yes, backface-culling could be disabled by a single line of code.
However, it's not something i'm going to do.
I don't think it is worth rendering hidden faces.

[Ronald_Reagan]

I don't think it is worth rendering hidden faces.

Rather than making new faces to render instead? What would be the difference performance wise?

[Luc@s]

Backface-culling isn't done with modelling, some coder (lucas?) has to get his fingers on this. It's an openGL/DX feature which, at least on DX, can be set for each entity separatly. Though, it could just be set for all models except the player and hud models if things should kept simple, in our case.

You pretty much just pass the info whether or not backfaces should be culled to the graphics card. I guess it's merely a single line of code at the loading function where the particular gl flag gets set.

However, I'm quite certain some simple algorythm which would leave out very small or flat models according its bounding box's size wouldn't be such a bad idea. I have models like signs or those screw and cigarette in mind actually.

Yes, it could be done with very little code.
But i'm not going to do that, because it's isn't worth rendering so many extra hidden faces, imo.

[|HP|]

"mdlcullface 0" in some md3 tags ?
But ofc people can edit that same as they can edit default map config file:D

Example on a single plane:

Spoiler

[Cleaner]

Backface-culling isn't done with modelling

?????

Can be set individually to any model with 'mdlcullface' can't it?

[Mr.Floppy]

Cleaner, you're right. I just remembered this config command when I went to bed and the computer was switched off already. Though, is the config file checked by the server? I'm afraid anyone could just remove that command and we'd back from where we started. Even worse, since this stuff is client side, unaware people wouldn't know and suffer from an extra disadvantage...

However, lucas already pointed out why this isn't a good idea at all. The odd thing about this is, you could argue against full-poly modelling (when not neccessarily required for same visual results) just the same. It does put quite an extra load of work on the GPU, too! That's why I was sort of baffled about this pardigm change, namely full-poly-instead-of-masked-single-face, in first place.

Well, summing it all up I guess my point is, whether we wan't to prevent those few crap-mapping folks from silly model abuse at the expense of everyone's performance? How far do we want to push this? Where to draw the line?

See, those mapping restrictions have all been about keeping maps cope-able for the engine. Now, this approach is pretty much going the opposite direction regarding performance. Sorry if I may be making a big deal out of nothing, but I'm seriously confused and to me it looks like you're way too much caring about those un-regular ongoings instead of the real game, in this case.

[Cleaner]

tbh, as far as my understanding went I only saw the good points in it and was totally unaware of the downfall (which Luc@s explained to me last evening on irc)...

Basically it's a 'draw' and 'render' thing...

Cool! It occults inner models views.
Cool! Even if you have some polys facing the wrong way your model still renders nicely.
Cool! The engine doesn't 'render' faces outside FOV.

But then...

If the engine do still 'draw' these faces and in this case has doubled it's amount then it's obviously a no no!

About cfg's mess-abouters you also have a point.

So at the end of the day the new rule would be to avoid mdlcullface command at all costs and since models are now fully sealed and decals double-faced I can't see any valid reason to use it at all.

[Ronald_Reagan]

About cfg's mess-abouters you also have a point.

I'm not sure he does. It isn't a command found in the map.cfg, and the only place that really uses these glitches is noob-maps. So yeah, they could modify the .cfg of every model in order to play their maps, but it would still solve the problem for the most part.

[Boeufmironton]

hy ! thank's for all this replies !

sorry i was working for 4 days.

One thing i diden't understand (cause of my bad english) can you shoot through a plane with .png transparent skin ? (i mean where there color disepaeard) ?