Gamestudio Links
Zorro Links
Newest Posts
Newbie Questions
by fairtrader. 12/06/23 11:29
Zorro Trader GPT
by TipmyPip. 12/04/23 11:34
Square root rule
by Smallz. 12/02/23 09:15
RTest not found error
by TipmyPip. 12/01/23 21:43
neural function for Python to [Train]
by TipmyPip. 12/01/23 14:47
Xor Memory Problem.
by TipmyPip. 11/28/23 14:23
Training with command line parameters
by TipmyPip. 11/26/23 08:42
Combine USD & BTC Pairs In Asset Loop
by TipmyPip. 11/26/23 08:30
AUM Magazine
Latest Screens
A psychological thriller game
SHADOW (2014)
DEAD TASTE
Tactics of World War I
Who's Online Now
7 registered members (3run, miwok, AndrewAMD, Quad, TipmyPip, fairtrader, 1 invisible), 637 guests, and 2 spiders.
Key: Admin, Global Mod, Mod
Newest Members
fairtrader, hus, Vurtis, Harry5, KelvinC
19019 Registered Users
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 5 of 7 1 2 3 4 5 6 7
Re: See Through Polygons #2220
04/23/01 03:34
04/23/01 03:34

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



Well I wasn't able to spend a lot of time with 3DGS yesterday but so far with the models vertical size down to 250 quants we still have the transparent polygon problem. Sac, last month I had a post at:
http://www.conitec.net/ubb/Forum1/HTML/001678.html

where I ran into a problem with model size and the invisible wall. Take a look and there might be some correlation with the problem that you are having where the automatic assignment of say the Narrow Fat is not working. And be sure that you fully understand the difference between a bounding box and the fat and narrow hull and how they will relate in size and configuration compared to your models size and configuration.

And yes the list of questions is not short but it is not long either. I do hope Doug does take the time to answer each question in detail as I think each one is very important to know and to understand. And Sac, if what you said about the near and far camera plane is correct then I don't see how that would apply in this case. What I understood from what you said concerning the Near Camera Plane would be the closest point to the model that the camera would be able to render the model correctly. What Fink and I have found is that you do not have to be right up to the surface of the model for this problem to appear but some distance away.

When I noticed this problem in the beginning I needed to be very close to the model surface and also be at the bottom of the model and then look up to see the transparent polygons. I have found out that if instead of being at the bottom of the model you center yourself with the model in a vertical direction. Now you approach the model and you do not have to get very close to the surface for the problem to appear. And it is not always necessary to look up or down but the problem also appears when viewing in a horizontal direction.

I found that if the monitor screen is overrun at the top and the bottom by about 25 to 30 percent at the bottom and 25 to 30 percent at the top of the screen of the model in the vertical direction the problem begins to appear. To make sure that you are in the center of the model press the "D" key so that you can read your viewing angle. Now with the arrow key look down at the bottom of the model. Keep the arrow key pressed so the bottom edge of the model is going to the top of the screen. When the bottom edge of the model just goes off the top of the screen your angle should be about 56 to 58 degrees. You need this same angle for the top of the models edge, this way you know that you are centered on the model in the vertical direction.

Now at this time I have reduced the model to 250 quants in vertical size. The only position of the camera that will give me a transparent polygon is if I am near the top edge of the model and slightly look in a downward direction. I am going to continue to reduce the model size and see what I can come up with but this weekend has been pretty full.

Now maybe this is telling us that there is a minimum percentage of the polygon that must be in the camera view or otherwise clipping may result. But then again Finks cube does not seem to be large enough where this would hold true.

Now since Doug has mentioned the possibility of polygon clipping we have tried to zero in on this as the problem. What is still curious though is that when I went inside my model to observe the problem for the possibility of the Normals flipping I was able to see the outside texture of the model from the inside on the polygons that were not holding steady. In this case from the inside view of the model, all polygons should be transparent but when you can see your outside texture from the inside of the model on the unstable, flipping or clipping Polygons it gets you to really wonder what the actual problem is. Maybe it is a combination of things where the actual root problem lies with the polygons being clipped for whatever reason but one of the visible cues is an apparent Normal being flipped.

I guess it is really up to Doug with his A4 engine expertise to ultimately solve this problem where we can work and not be hindered by this.

Ron


Re: See Through Polygons #2221
04/23/01 15:04
04/23/01 15:04

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



I read ur post Ron, but i'm using the default gaurd model as my player and with a scale of 1. do u think it will be the problem of the model passing through the the wall block at one place and not at another place ???

Regards,
Sac


Re: See Through Polygons #2222
04/24/01 01:04
04/24/01 01:04

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



Sac:

With a model using a Bounding box, fat or narrow hull----yes, depending on the shape and size of the model. With a map entity---no, unless you have asigned a push value or passable. See the On Line Guided Tour under Terrain Entities and the manual pages 81 and 82. Will send you an E-mail with some suggestions. Your see through polygon problems seems to be the same as ours but your other problem collision detection, is different. I would like to keep this thread centered on the polygon issued so Doug can focus on it.

Ron


Re: See Through Polygons #2223
04/24/01 03:39
04/24/01 03:39

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



I very well understand that the focus of this thread is see through polygons... i will not deny it at any case Ron... but i should also have a solution for the other problem also right ?? i didn't want to open a new thread for that...... i hope u understand....... even this problem is very much big and as much important as see through polygons......


And do send me the suggestions ...i'm very much eager to see it........

i hope Doug or Jcl will help us both soooooooo soooooooooooooooooonnnnnnn.......

With regards,
Sac

[This message has been edited by sac (edited 23 April 2001).]


Re: See Through Polygons #2224
04/24/01 21:22
04/24/01 21:22

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



Doug:

I took yesterday off from work to see if I could come up with some more information on this problem. What I found was that if I scaled the canyon model down to 0.13 I could still get one polygon to become transparent. At a scale of 0.125 there were no transparent polygons that I could see.

At a scale of 0.13 the vertical height of the model is 200 qauants and the horizontal width is about 650. At a scale of 0.125 the vertical height of the model is 190 qauants and the horizontal width is about 635.

It also seems apparent when the model is scaled down (Slightly larger than the above scaling) that the farther the camera is above the ground that you have to back away from the model a little to see the transparent polygons until you reach about the center of the model. Then as you continue to move verticaly it seems necessary to start comming closer to the model.

The last polygon to become transparent is in the center of the model at the top. If you come towards the model at about 75% of its height and fill you screen until the top edge of the model covers about 80% of your screen you will see the transparent polygon if you look slightly down. You may have to move slightly up or down and maybe a bit to the left.

I am lost now as I do not know what the solution is or the root cause. All I know now is that it appears that a model will have to be less than 200 quants high.

Can you please answer the questions that I have posted below. I know that many of us will appreciate it very much.

Ron and the rest of us.


Re: See Through Polygons #2225
04/24/01 22:40
04/24/01 22:40

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



Ron: I have not read this whole thread but as far as I understand you have a model with some invisible polygons - right? Is it a MDL or HMP? Which A5 version do you use? Is the visibility depending on the camera distance - and if yes, have you checked the clip_range?

If the solution for your problem is not obvious, it could be necessary that you send us the model for examination.


Re: See Through Polygons #2226
04/25/01 06:31
04/25/01 06:31
Joined: Jul 2000
Posts: 8,973
Bay Area
Doug Offline
Senior Expert
Doug  Offline
Senior Expert

Joined: Jul 2000
Posts: 8,973
Bay Area
The near clipping plane is something used internally by the 3D engine to help clip and project polygons. I kind of regret bringing this subject up since this is an internal 'engine thing' and not something you can change (nor should you really want to). If you want to learn more about clipping planes, projection, and the 'view fulcrum' I can suggest a couple of books on these subjects (some of them are even understandable to people without a degree in rocket science ).

The reason I mentioned this is that the effect you are describing sounds like it might be related to the near clipping plane. But only JCL could really test if this is true or not.

Even if we do find a fix for this I would still encourage you to use map entities rather than such a large mdl. On weaker 3D cards you will get a "triangle too big for 3d card"


JCL:
The problem appears on the 4.23 standard engine (I can forward you the files if you like). It looks like A4 is clipping large polygons when part of them are extending past the near clipping plane.



Conitec's Free Resources:
User Magazine || Docs and Tutorials || WIKI
Re: See Through Polygons #2227
04/25/01 15:05
04/25/01 15:05

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



Doug/Jcl,

The Cube in those screenshots below is only 24 x 24 quants.
The map entities(map entities!) in Sacs shots are also way smaller than Rons Model.
Are these 2 different problems?
Do we need, as Ron has stated in his last post, to keep models below a certain size in order to avoid his problem?
I assume that you guys are assuring that an upgrade to A5 will fix all these problems...just my problem?? or just Rons problem if in fact they are 2 different problems?
No demands here (Im still a happy camper) Im just getting confused. The default clip range (that Im assuming no one has altered) according to the manual is set at 100,000 quants.


Re: See Through Polygons #2228
04/25/01 18:15
04/25/01 18:15

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



The size of models does not matter. Only the camera position in relation to the model polygons is relevant here.

Of course, if you have a large model, the camera can penetrate more easily a part of it as with a small model - do not forget that the collision detection is based on the bounding box, but not on the real size of the model. If a model polygon intersects the camera plane, it is clipped away. This is normal behaviour of the 3D card and does not indicate a bug.

[This message has been edited by jcl (edited 25 April 2001).]


Re: See Through Polygons #2229
04/25/01 21:29
04/25/01 21:29

A
Anonymous OP
Unregistered
Anonymous OP
Unregistered
A



Doug and JCL, thank you for both responding. If the problem we are encountering is do to polygon clipping then no I don't think this is a bug either but a normal limitation of the nature (rendering type) of the engine and is not a reflection of a deficiency of A4 or A5.

I started making my first models with another engine that the game Descent II used. I forget the rendering type but on the models when you positioned the polygons you needed to make sure that the horizontal plane of each polygon did not intersect another horizontal plane of another polygon on the model. The polygon planes were considered not to end where the visible edges seemed to indicate but extended out to infinity. If these planes did intersect then you had clipping of the polygon and you then could see through what appeared to be a solid surface on the model. The restriction was that the shape of each block that made up the model had to be convexed just with A4 and that the planes of each polygon in each block could not intersect with another plane of another block or you would also get clipping.

I thought that A4 used a different type of engine because I never read anything about a restriction in the placement or orientation of polygons on models or with the blocks that make up the world. And the basic difference in construction of the world was with the Descent II engine you were always inside of a block and never saw the outside of another block unless you joined two of them and at the intersection of the two blocks you assigned this plane as a wall.

I think there is still a little confusion as to the method to be used in preventing the occurrence of this problem. It would be my understanding of the camera plane as the camera being at the apex of a four sided triangle pyramid that was laid on its side. The four sides representing the four sides of the monitor screen. The bottom of the pyramid representing your maximum viewing angle. Clipping would occur if the sides of the pyramid intersected with a polygon that was larger than the bottom of the pyramid.

Fink made a model of a simple cube and got close to it so that explanation is good. But Sac has a very small wall and is not close to the wall at all. And also Sac's wall is not a model but a primitive that would not seem to intersect with the camera plane if I understand the plane correctly.

Now since this appears to be the nature of the beast which we have to work with it might be better if you could give us some specifics so as not to encounter the problem anymore. I am sure that there are many other people out there that have the same problem but who have not posted and are just reading. I really think we need your help in using a work-around that will give us consistent good results.

And thank you again, both of you

Ron, Sac, Fink and everyone else.


Page 5 of 7 1 2 3 4 5 6 7

Moderated by  HeelX, Spirit 

Gamestudio download | chip programmers | Zorro platform | shop | Data Protection Policy

oP group Germany GmbH | Birkenstr. 25-27 | 63549 Ronneburg / Germany | info (at) opgroup.de

Powered by UBB.threads™ PHP Forum Software 7.7.1