Polygon counts and Textures

Bazza, this is such a helpful tip! thank you ^_^

Just some ideas on textures and poly counts as a response to this post by Howard…
[img:1ugxiwno]http://amabilis.com/forumattachments/a/tpc/f/9856056974/m/23510381931?r=44310222931#44310222931[/img:1ugxiwno]
<!– m –><a class="postlink" href="http://amabilis.com/forumattachments/a/tpc/f/9856056974/m/235…10222931#44310222931">http://amabilis.com/forumattachments/a/ … 4310222931</a><!– m –>

Although Howards question was regarding train simulators the same problems apply to almost any scene you are creating.
As Pete mentioned in the above post it all boils down to how much scrutiny each part of the scene will receive.
ie…How close the camera gets to the model, is going to determine the amount of geometry that needs to be built into the model AND the size and quality of the textures used.
If your not careful you can end up spending hours and hours building detail into say, a model of a building, but the camera never gets close enough to see all the work you have put into it. Plus the poly count can get completly out of hand as you add extra buildings to the scene.

Also remember the final polygon count is NOT the same as the face count in 3DC (Unless you have triangulated the model).
3DC like most 3D modelers uses quads (four sided faces) in it’s basic building geometry, when you export the model these quads will be triangulated, so as a rule of thumb, if you double the face count of the 3DC model this will give you a ROUGH idea of the final polygon count.

Anyway, my fictional, international roundhouse scene is a good example of sorting out the problems and the priorities.
It’s still very,very WIP. The textures are still very basic and need more work although I have included some further down this post, plus I need to get more clutter built into the scene.
I don’t use a train simulator, although I would like to, I find them to restrictive for my needs so these shots are from Blitz3D.

So the problems are…
I would like to get at least 7 or 8 loco’s into the scene…more if possible. Each loco is around 15,000 to 20,000 poly’s.
So before I even start I’m looking at a final scene poly count of at least 160,000 polys just for the loco’s.
Plus everything stll has to work ok…the turntable, animations and the particle engine for the steam effects can’t have any slowdown.

So I have to keep the poly count for the buildings and the rest of the scene down to a minimum. As it is, the complete scene without any loco’s but including the turntable is just over 4000 poly’s.

[img:1ugxiwno]http&#58;//img92&#46;imageshack&#46;us/img92/1746/rounhouse3ff7&#46;jpg[/img:1ugxiwno]

The distant buildings are VERY low poly…only around 50 poly’s each with very small 128×128 faded textures applied, the camera will never get anywhere near these.
The roundhouse stalls and workshop fronts are still very low poly..just over 2000 polys for the lot but the camera can get quite close to these.
So instead of building in loads of geometry (window and door recesses etc) you can create a very good effect with a 3D texture applied to a flat surface.
The front’s to the stalls are built completly flat…even the curved cornice at the top is created with a texture.
It’s a constant trade off between textures and poly counts, always think what you can ‘get away with’ by using a texture and what needs to be created using geometry.
In the lower pic, again these walls are all built flat, there are no recesses built into the model for doors and windows.

[img:7jw0m2wf]http&#58;//img92&#46;imageshack&#46;us/img92/5841/buildingsby4&#46;jpg[/img:7jw0m2wf]

I’ve included some of the textures as they are at the moment, use any of them as you wish. Most are still WIP and I’ve had to use .jpeg for the file format. So if you want to use these, save this image, then select each texture in turn and save as a .bmp file to work on.
I did a tutorial on 3D textures if you want to try creating your own stuff. All you need to do is to decide from which direction the light is coming from. I usually go for top or top left. Then apply the highlights and shadows to create the recesses etc.
For the wall/door texture at the bottom of this image,I went for a top left light scource. This would give a shadow on the door and grills along the top and left edges and a highlight on the right and botom edges of the brickwork around each recess.

Note the window with the bars on it…the shadow is displaced quite a way from the bar itself and gives a greater feeling of depth.
I used this in my City Scape scene, sent it to
James(Polybuilder) and he wanted to know how I had created all the window bars in 3DC. <!– s:D –><img src="{SMILIES_PATH}/icon_e_biggrin.gif" alt=":D" title="Very Happy" /><!– s:D –>
Just goes to show a good texture can fool even the best of us.

[img:sw1o6pri]http&#58;//img92&#46;imageshack&#46;us/img92/9289/textures1tg7&#46;jpg[/img:sw1o6pri]

Same comments as above but note how faded the textures are for the distant buildings.

[img:1i58wo64]http&#58;//img92&#46;imageshack&#46;us/img92/7940/textures2hw8&#46;jpg[/img:1i58wo64]

A couple of pics from 3DC showing how the model is built, the face arrangement and how the textures are applied to each of the faces.
You work from the ground up and really need to be working to some kind of scale. I make my doorways 7ft tall then add the height for an imaginary ceiling above the door…say 2 ft. So this ground floor face (pink) is around 9 ft along the y axis.
Next start extruding the building upwards, usually by the around the same height as the ground floor. This helps to create an even amount of scaling especiallly when applying brick textures to each of the faces.
Once you get above two floors your textures don’t need to be super detailed as the camera very seldom gets close enough and a slightly blurred texture here will add to the appearence.

[img:2af1pnb9]http&#58;//img92&#46;imageshack&#46;us/img92/5798/faceshy8&#46;jpg[/img:2af1pnb9]

For the distant buildings you can drop the poly count and texture sizes right down….this one has only 56 polys and three small 128×128 textures.

Thats it really…if your 3D engine allows you to add a fog/mist effect you should be able to fade the distant buildings.

All I need to do now it to build another 6 or 7 loso’s. <!– s:( –><img src="{SMILIES_PATH}/icon_e_sad.gif" alt=":(" title="Sad" /><!– s:( –> <!– s:D –><img src="{SMILIES_PATH}/icon_e_biggrin.gif" alt=":D" title="Very Happy" /><!– s:D –>

Bazza

[img:27ilr5wt]http&#58;//img92&#46;imageshack&#46;us/img92/4416/faces2zv9&#46;jpg[/img:27ilr5wt]

[BLOCKQUOTE class=’ip-ubbcode-quote’][div class=’ip-ubbcode-quote-title’]quote:[/div][div class=’ip-ubbcode-quote-content’]Originally posted by Bazza:
Also remember the final polygon count is NOT the same as the face count in 3DC (Unless you have triangulated the model).
3DC like most 3D modelers uses quads (four sided faces) in it’s basic building geometry, when you export the model these quads will be triangulated, so as a rule of thumb, if you double the face count of the 3DC model this will give you a ROUGH idea of the final polygon count.
[/div][/BLOCKQUOTE]
The ‘Count triangles’ plugin gives the number of triangles.

Thanks for taking the time to do this.

Thanks Alan…I appreciate the feedback,it took about three hours to put it all together and I forgot about the Count triangles, thanks Dom.
I’ll do a part two when I get the time and include some of my base textures.

Bazza

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