Jump to content
  • Advertisement
Sign in to follow this  
Spiderweb

Tree model is 2k poly entirely outta the question?

This topic is 5060 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi, Ive recently took up modeling and started with a craft as they say you should. Then I tryed my hand at a character that I think is decent but I am putting it on hold until I've honed my skills some more. I made a few trees that look awesome but the problem is that the poly count is very high. This tree nearly looks real. I made independant triangles for the leaves. Is there a few people here that can maybe give me some better ideas how to do this and still maintain a nice looking tree. I understand that you can make a 2 d surface that turns with the player to give the effect it is 3d, as well I saw that in the game Dark age of Camelot, they made an X pattern out of the 2D surfaces to give it more depth but it did not turn with the player. (hated that tree in that game) I hope someone might have some better ideas to help me figure out this problem.

Share this post


Link to post
Share on other sites
Advertisement
make a cylinder and taper it towards the top (trunk)
make some rectangles (branches)

jitter the rectangles anlong the trunk
scale the rectangles so that the higher branches are smaller

make a picture texture for the branches
make an alpha map for the branches
^these two maps should match up (just make the alpha map a monochromatic version of the texture

apply both of these textures to the object

then, the texture shows up accordingly and blank areas in the textures are transparent

then, just texture the trunk....

Share this post


Link to post
Share on other sites
A tree model at 2000 polygons could be entirely acceptable, and it could also be ludicrous. If you're going to make a forest at 2k a tree you will run into trouble pretty fast, but if you're only going to have a few trees in view then you may even be able to bump it higher.
Any model's polycount level should be entirely relative to the scene it is in.
Also keep in mind things like texture resolution and overdraw (blended textures can really kill performance if they cover a lot of the screen, especially if you layer them too tightly). If every leaf has a 1024x1024 texture and they're all clumped together into a tight bunch you'll probably be able to notice the tree by the sharp frame rate drop it creates whenever it comes into view. ;)

As for how to model them, it depends on the tree type. "Tree" is a very broad term, and there are hundreds of different styles of polygon layouts you can use for different ones. Your best option is just to look around and see how people have done it in the past. They all has pros and cons; some look good from afar, some envelop the tree so the player shouldn't be able to get inside, etc.

Just never do an X pattern if you are ever going to get anywhere remotely near to the tree. Do that and you should be thrown in jail for cruelty to hardware, unless maybe your hardware is 8 years old.

Share this post


Link to post
Share on other sites
Why not shaping variations of the tree ? One for staying very close , one for being some steps away, and one for wide away for example . And then use LOD to show the mesh that´s necessary dependand of the LOD distance .

There are various ways to shape low poly trees . Smallest is to map a tree at an simple poly that always shows directly to the camera. Good for the LOD trees that are far far away . Next is to cross this poly with the tree at it ,so that you can look at this tree from all sides . Between 3 and 5 Polys should be enough for that . You could also use different angles snapshots of your original tree, which gives you more realism.

Let´s go to your low poly tree that you stay close to . Make your trunk and branches by extruding cylinders (or by using polys like mentioned by xchronus). Texture it . Should be between 500-1000 polys maximum . The leafes can be made of single textured polys that are crossing itself like you did before . Note: not a single leaf , but lots of leafes for the texture . Make a bunch of leafes with your polys .

Tip : model from small to big when you use single polys for the leafes . First create your bunch of leafes, then attach this bunch to a branch . Then attach this branch to the trunk . this way is easier than trying to bring the bunch of leafes to its right position at the tree ...

Or use a Sphere or Geosphere ( this has less polys ) for the leafes, cut away half of it : the lower part , and texture the top of it with your leafes texture. Then place your leaves into the tree . The last one with the geosphere should be the one that you are looking for : lowpoly but somehow good enough looking . Make some experiments , and i think you can bring it down to a few hundret polys . This geosphere also has the advantage that you can look at the tree from all angles without looking at the border of a poly like you would have in the single poly leafes way :)

Share this post


Link to post
Share on other sites
Thank you for the info. Im trying to professionalize myself a bit more in this area but I will admit, I have far to go. I have to learn these tricks if I am ever going to be good at this :) Ill try all these methods. I think my tree with no leaves is higher poly that with the leaves alone. Does anyone have a example tree they could show me?

Share this post


Link to post
Share on other sites
Guest Anonymous Poster
priortise workin on good looking high poly models before you worry about poly counts..
the polycount for games only goes up... not down... it's easier to go from high to low then the other way round...

as for low poly tips...
You can add a lot of detail with good texturing...the silhouette of the model must be made with poly's though...

So just think of the silhouette of the model from the main viewing angles when creating it... Then add the detail with textures...keep in mind how close you are going to get to the model ingame...

example..I am modelling a female character.. i would pay attention to getting the right curves, lines or silhouette from viewing the character from the front or side...and i would do this through modelling... Details such as the womans bare belly button would be textured in though as it is not part of the silhouette and the texture would fool most peoples eyes anyway... modelling it would be better but not at the cost of the polycount...

hope that helped!

Share this post


Link to post
Share on other sites
I've run into a similar problem while working on trees for the historical RTS game 0 A.D. - how to make trees look as real as possible by utilizing as little polygons as possible. One of the initial goals I had for the trees was to make each leaf visible, but clearly I can't model each leaf out because the game is expected to have forests of 30 or more trees visibile on the screen at times.

So the modelling method I came up with worked very well - I modelled out the trunk and the branches (totalled arround 150 polygons) and then applied a 128x128 branch texture to a triangle, then I moved the triangles arround to create a canopy. The result worked out exelently and there are no more than 50 transparent polygons in the tree. It looks amazing and the game will be able to have many of them on the screen with no problem.

Ingame pics:








Share this post


Link to post
Share on other sites
In most 3d engines isnt there an " INVISIBLE " color... ie you texture something that color and you cant see it? Correct me if i'm wrong.... but why couldnt you just make a bunch of little triangles or something simular and just apply the texture to that making a bunch of little spaces to look like leaves?

Share this post


Link to post
Share on other sites
Quote:
Original post by JeffHealey
In most 3d engines isnt there an " INVISIBLE " color... ie you texture something that color and you cant see it? Correct me if i'm wrong.... but why couldnt you just make a bunch of little triangles or something simular and just apply the texture to that making a bunch of little spaces to look like leaves?

You are referring to the 'alpha' channel or simple colour keying. Yes there is such a thing and I, too, tend to use it for things like trees.
It's much simpler to just create a triangle and assign a partially transparent texture to it, than to model each and every edge of a leaf.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!