Go Back   AC3D Forums > General > AC3D General
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 2nd July 2004, 11:29 PM   #1
INNIS
Member
Advanced member
 
Join Date: Oct 2003
Location: Australia
Posts: 34
Default Large files and AC3D

Hi All

I have an aircraft model file that is about 2.5meg that I am trying to open
and work on.But AC3D takes about ten minutes to open it and when it does
there are many objects/surfaces missing with just the vertices showing.

1)Can I get AC3D to open these files faster buy alotting more memory for
AC3D to work with.If so how.

2) Are these files considered large by AC3D standards.They have about 60000
vertices.

Thanks for any help you can give.

Cheers
Innis
INNIS is offline   Reply With Quote
Old 3rd July 2004, 12:22 AM   #2
Dennis
Senior Member
Professional user
 
Dennis's Avatar
 
Join Date: Jul 2003
Posts: 899
Default

Hi Innis,

I'm currently working on an AC3D model with 64,000 vertices, 68,000 faces. It takes about 4 seconds to open, and I'm running on a P4 2.4ghz with 512MB of RAM, under Windows. I notice some lag while editing with all objects showing (i.e., not hidden), but definitely nothing serious. I'd say that this is not an inordinate size for a model in AC3D - however, it may depend more on your system specs.

When your model takes 10 minutes to load, is the model already in AC3D format, or are you converting from another format? Conversion can be slow, depending on the format and contents.

Also, my model has all of its faces/vertices in 25 different objects - this allows for very fast editing/operations. However, if every surface were in its own object, it would be painfully slow to work with (and I'm almost certain that would slow down the loading, but haven't experimented with that).

If you have the patience to open this thing again, try going to the Tools menu and select "Model info...". At the very bottom, you should see a line like this:

Total objects: 25 surfaces: 67984 vertices: 63736

What do you have there? You may have a high object count, or a low surface-to-vertex ratio (which can be optimized by using "Object | Optimize vertices...").

Also, re: memory allocation --- are you using Windows? If so, Windows should handle all memory allocation, and will take whatever the app needs. If you're talking about pre-allocating memory, I'm not sure how to go about doing that, but it's probably best to let Windows manage it. I doubt the app claiming memory blocks is a big bottleneck, anyway, although I could be wrong.


Dennis
Dennis is offline   Reply With Quote
Old 3rd July 2004, 05:58 AM   #3
INNIS
Member
Advanced member
 
Join Date: Oct 2003
Location: Australia
Posts: 34
Default

Hi Dennis

Thanks for the reply
The system I am using is an 850meg duron(not exactly state of the art)with
a GF4MX420 card under windows 98SE.
The model is already in AC3D format but it is a conversion from a DXF file using the PPE program.
Also in the conversion every surface is an individual object and it is not till
I get it into AC3D that I can optimise it again.
I find currently I can get a 850k file to load in about 3 minutes with about
25000 vertices but the 2 meg file takes some time.I could live with that if
I have to but if I am losing some of the surfaces in the process then it is not
worth the bother.
Thanks again for your help

Cheers
Innis
INNIS is offline   Reply With Quote
Old 3rd July 2004, 08:59 AM   #4
Dennis
Senior Member
Professional user
 
Dennis's Avatar
 
Join Date: Jul 2003
Posts: 899
Default

Hi Innis,

I ran another test to see what would happen if I separated my model into individual objects, and the times you're seeing seem directly related to having all of your surfaces in separate objects, I separated my model into one-surface-per-object, and the model took over 5 minutes to load (given the specs I posted previously).

One suggestion I'd make is once you get the model into AC3D, perform the following steps:

1. Select all objects/surfaces and perform an "Object | Merge" (ctrl+shift+m). This will be very time consuming, but probably not much longer than your load time, if at all.
2. With all objects selected (should only be one object now), perform an "Object | Optimize vertices..." (ctrl+shift+v). This will be a very slow operation as well.

This places all of your surfaces/etc into a single object - now, to group the objects the way you want them, go into surface mode and select the surfaces you want to separate into a new object, then perform a "Surface | Cut-away object" (ctrl+shift+x) - repeat for every "section" that you want in a new object. You should find all operations at this point to be *very* quick by comparison.

As you break your model into objects, you'll found that Hiding objects you're not currently working with will speed up editing immensely. I definitely see a lag on my 64k-vertex model when I don't hide anything and am viewing the whole model, but once I start hiding sections I'm not working on, the speed increase is significant.

Try this with your high-poly model and let us know how it works out. You're probably looking at a lot of processing time to perform this step for a single model (sounds like at maybe 1/2 hour, maybe more or less) - is this something you'll end up doing many times?

Dennis
Dennis is offline   Reply With Quote
Old 3rd July 2004, 11:04 PM   #5
INNIS
Member
Advanced member
 
Join Date: Oct 2003
Location: Australia
Posts: 34
Default

Hi Dennis
Thanks again for the reply
Almost every thing you mention I already do
and from what you are saying there does not
seem to be much difference between the time
your machine takes to do the job and mine.
Yes I find that it takes about the same time to load
the model as it does to do the fragment after that I am
laughing as I can then hide most of the model and
optimise it down into much more manageable chunks.
The only problem I have left now is the realy large
models seem to load with large areas of the model
missing which makes the whole exercise pointless.
Is there a maxium size file that AC3D can handle
or should it be able to handle all files.

Thanks again
Cheers
Innis
INNIS is offline   Reply With Quote
Old 4th July 2004, 12:50 AM   #6
Dennis
Senior Member
Professional user
 
Dennis's Avatar
 
Join Date: Jul 2003
Posts: 899
Default

Innis,

Ah, I see now - my bad - I was thinking that when you said you were missing surfaces that it was due to your own reducing the size of your file. I didn't get that the model wasn't loading in completely from the source file.

This certainly wouldn't be due to any AC3D size limitation of which I am aware, based on loading some models comparable in size to yours.

Also, I re-read my last posts and realized that my verts were more and my timings were exploded because when I fragmented the objects I ended up with 64k * 4 vertices in separate objects... so I was loading at least 256,000 vertices in those tests, and everything came through ok, if slow.

Do you see any errors on the console window when opening the file?

Have you ruled out whether PPE might be writing something glitchy to the AC3D format? For example, have you tried exporting the file from PPE to DXF or another format that AC3D reads and tried importing that directly into AC3D to see if any polys were dropped? If the data comes in ok from another format, I'd guess that PPE's AC3D output may have a glitch - I'm not familiar with PPE, so if I'm off-base with this approach, please ignore.

Barring any new info you might find on the PPE export front, this may be an AC3D quirk where your particular model is concerned. If you have a sample you'd like someone else to try out, you can send me a private message and I'd be happy to load up, say, an AC and DXF sample to see if I get the same results/dropped polys as you.

Good luck,

Dennis
Dennis is offline   Reply With Quote
Old 5th July 2004, 02:19 AM   #7
INNIS
Member
Advanced member
 
Join Date: Oct 2003
Location: Australia
Posts: 34
Default

Hi Dennis
Thanks again
I did not know that I could import a DXF file onto AC3D.
I will have a play around and see if I can figure something
out.
Once again thanks for you help.

Cheers
Innis
INNIS is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -4. The time now is 12:25 PM.


AC3D Forum
(C) Inivis Limited 2020