Trees

Jessica Dinh

Hello! I am making a game with some of my peers, and have been assigned to model environment props - trees, rocks, crystals, etc. In this game, the outdoor environment is quite important, but my tri-limit is still lower than I'm used to. I need to stay close to 500 tris for my props.

I've never made a tree before, or anything quite so organic, so I would love lots of opinions, tips, and critique! Here is a few minutes of progress on my first tree. I started with a box primitive - I thought it might be better to sacrifice a little of the round-ness of the tree in order to have more tris with which to match an accurate silhouette to the reference. So far the tree is 336 tris and I still need to make the leaves. I just wanted to put up the beginnings of my process in case anybody sees that I am starting off in a completely wrong direction. Please catch me if I am!

By the way, I am planning to make high poly and bake normal maps as well.

Here is the concept by my friend Nick de Spain. Sorry it is a little small , if this is too small for anybody, let me know and I will redraw it bigger myself.



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Thanks!
Jessica

Hayden Zammit

Right where it forks off in the concept pic, it looks like there's a baby's face in the tree haha.

It's looking pretty good so far. I don't make many trees, but maybe you'll need some more tris up where it forks.

Mark Dygert

What program are you using? 3dsmax? Crack open the graphite modeling tools, and check out the branch feature, its awesome for stuff like this. Incredibly fast and organic.

Addieo

A box turned at 45 degrees looks an awful lot rounder than what your doing. Maybe even look into triangles? You creating those hanging parts with planes?

Goat Justice

500 Tris is a pretty low poly tree. What type of perspective will your game have? If it's a first person or over the shoulder sort of view you might want to use a few more polys for the trees, especially if they are significantly larger than the player.

I'm guessing only the one root on the left is fully modeled out? The other three look pretty boxy and non organic. If you had to sacrifice a root, it would probably be worth it to get three nice twisted ones.

Snader

You need to triangulate more. It's very obvious to see how you made it, where the extrusions are and it looks very boxy.

What I usually do for lowpoly organic shapes, is extrude, then rotate a bit, extrude again, etc. This will make the shapes more random looking. Here's an example (222 triangles) of the bottom part of the tree with that technique:

Jessica Dinh

Yep, I'm not done with the roots yet, not even the left one - all of this is kindof a block-in.

Also, what my directions actually were: 500 tris for small props and 1000 tris for larger ones. The reason I initially felt I should use 500 tris is that this game is third person and the trees will be seen from a distance. Still, all of your feedback has helped me to decide I should probably consider this a large prop and give myself 1000 tris (or at least a little more than 500) to work with. I'll start over with a cylinder prim instead - it should look a lot more organic!

And thanks Snader, for your little demo! ^_^ I don't know why I wasn't using rotate tool - just the move tool, and it was warping my faces and making some parts of the branches look stretched and weird

I'm not sure if I will use alpha planes for the moss and squiggly toppers, or actual geometry. I need to figure out which will turn out to be more expensive first.

Ok let me try again, I will post soon.

Jessica Dinh

Ok, here is a wireframe. I'm going with alpha planes for the foliage, but this is my first time using alpha planes, so I have a question:

I made a plane, duplicated it, and flipped it so that you will see the texture on the other side (our engine does not support double-sided for textures). However, when I duplicate, should it be 'copy' or 'instance'? The problem with instance: when I flip the instanced plane, the old one flips as well. The problem with copy: if I copy the plane, then when I texture the original plane, the texture won't show up on the copied plane right?

Lowpoly, 734 tris:



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Confoosed! haha
Jessica

Goat Justice

At some point you're definitely going to have to copy the plane.

What I usually do for plants is make the alpha mapped leaf texture (or at least a silhouette stand in) first. I then make a plane in max and apply the texture. I can then cut and fold the plane if necessary, and set the pivot to a convenient location (usually the stem of the leaf bunch). I create instances or copies of that original and position them until I like the look of the plant. Once I'm happy with the leaves, Its time to duplicate and flip them.

Duplicating the leaves and flipping them is almost a part of the export process this way, and I usually keep a copy of my plant without dup'ed leaves for making edits. Once there are 2 copies of each plane it can be a serious pain to move thinfg around.

Its kind of an odd workflow, but for plants its often easier to have the textures first.

Jessica Dinh

Ohhh, I see. I appreciate the insight Goat Justice! Guess I'd better get to unwrapping and texturing then. Next update will be with textures - I'm going to try my hand at hand-painted! ahaha

Jessica Dinh

What are sprites? Or if you know of a good tutorial about them, do let me know ^_^

Jessica Dinh

Thanks Super Happy Cow! Our art director prefers us to use planes for the foliage, but I think I will read up on the sprites for future props. From what I understand so far, sounds like a great way to save tris.

.morph3us

you should definatly attach the different branches to eachother and relax the resulting edges, will look a lot more organic...

RexM

Getting your engine to support 2 sided planes would be simple and is honestly essential for real-time games currently. Without 2-sided support tri counts will be wasted too much.

I second the guy who said to make textures first. It helps you when you position the planes to get rid of the plane look.

I also agree that the entire trunk should be one mesh, will look way more natural.

Also, try this to get slightly more depth from the plane:

.morph3us

if you do throw a lot of planes together look into vertex normals, it'll make your canopy shade as a whole, not like individual planes scrambled together...

Baddcog

All two sided materials do in most games is add more tris.

So if you don't add the planes before export your tree will be 1000 tris. But in game it will be 1024 (or whatever).

So at least doing them in the 3d program will give you an accurate tri count.

I also do all leaves one sided, the copy/flip normals before export. (as said above less to work with = easier)

instance is great for doing things like biped where you only want to model one leg/one arm but see both sides as you go. But then you need to delete the instance, make a copy and connect it. For everything else copy is best.

I agree that connecting all the branches/roots would give it a bit of a better shape, but it's much better than the first.

Another way to save tris and get a nice round look. Start with box as you did first, but rotate each extrusion 45* from last (not in bend direction, in extrusion direction). So from top it would be square/diamond/square/diamond.

rotating one direction will pinch all the edges and look bad, rotating in the opposite direction will make the angled edges round it out. (no 3d program handy right now for example, sorry if that's confusing)

sprites (aka particles : aka billboards) are OK for some stuff. Big leafy trees for example. But they do spin weird if player is close and rotating (gives a kaliedescope effect). Oblivion trees use this method and we used them in The Dark Mod (as an option). They can look fuller than plane leaves though.
But for that tree they'd probably be hard to align correctly and you'd need a particle per branch end (expensive). Much better with just planes most likely.

RexM

If coded correctly, double sided planes will not add more triangles, like in Cryengine 2.

Baddcog

Now that you mention it RexM...

What engine will you guys be using? just curious. I suppose these days it's a good chance it's either UDK or Unity for an indie project. Since it's 3D. I don't know UDK but I believe Untiy would just create tris. But it might be possible to write a shader to fix that, though it might be coded in the renderer.

All the other engines I've used (Hammer, Radiant, Dromed...) created tris. None are as new as Cry2 though.

back to topic...

Jessica Dinh

It's actually neither Unity nor UDK, but a custom built engine in XNA. I don't know if it's because they haven't figured it out yet or if they just decided it would be better not to have double-sided, but our directors just told us to duplicate all of our planes. Honestly, almost all the trees in our game are pretty foliage-sparse and are instead defined by the shape language of the trunk and branches - in which case I guess that's why our directors don't mind us using duped and flipped planes.

Here is our website so far, with a trailer showing our progress:

http://www.unchainedgame.com/index.html

Jessica Dinh

Alright, here is an update before I unwrap. The branches and roots are attached to the trunk mesh now, and I will texture just the one alpha plane and copy it around later:

Jessica Dinh

Here is my color map! The model is about 780 tris on a 256 x 256 texture. Spec map and normal map coming. Critique welcome!



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Thank you,
Jessica

Baddcog

Looking pretty good. The wood tex looks really nice. But I think it could use more contrast.

I desaturated it and looked at the levels and almost everything is in a very narrow band.

If you increase contrast and just make sure you don't get black in there it should pop more.

Jessica Dinh

Thank you Baddcog! I have upped the contrast quite a bit here - hopefully the texture doesn't look so flat now. I also sharpened the texture a bit, but I wonder if it is too sharp so I'm looking for opinions. I pushed colors a little warmer too.

Normal, Specular, Color, Opacity maps:



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Rendered in UDK:



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Critique welcome!
Jessica

Baddcog

I think it looks better now.

too sharp? that depends alot on what you are going for in the game overall I guess. But looks like you are going for a 'hand painted' 'cartoony' vibe. In which case bolder colors fit the bill imo.

Looks like you're missing normals for the flower, they'd help round out the flat planes and give it more shape.

Looking foward to seeing more props.

Jessica Dinh

Hmm, normals for the flower? How would you go about doing that? Just paint a grayscale beveling effect on each petal?

Baddcog

Yeah, that's probably the easiest. If you don't get good results you could model it out and bake...

Jessica Dinh

Normal mapped flowers! I think that helped a lot - thanks again Baddcog! Another tree coming soon.



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Cody

This looks pretty nice. The one thing I see is that when looking at it from a side angle the tree is very thin, and doesn't have much of a silhouette. The trick with trees is trying to get a nice silhouette from all angles, maybe move the branches to each side and add a third, so you get some nice shapes from all angles. - These are all the things my art director told me at work when i was making trees a few months ago, so thought I'd share . Keep going!

Jessica Dinh

Thank you Cody! I'll keep that in mind while making my next tree. The concepts I have to work with are pretty loose and in some cases don't necessarily indicate dimensions, so I have a lot of room to play!

Jessica Dinh

New tree! I'm at 640 tris so far, before foliage alpha planes. In the end I would like it to be no more than 800 tris because I'm using 256 x 256 textures again. And question: the little floaty branch that I made, do you think you will see that it's floating through my foliage? Should I connect it down? Remove it entirely? I was just trying to save tris by floating it since you're just going to see the tip of it out of the foliage anyway. Also, to clarify, that kite shaped plane is one of my foliage planes - I will be duping it around later after I texture it.

Concept by Nick de Spain:



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Thanks,
Jessica

Baddcog

this one looks cool so far. I think it'll probably be hard to disguise that floater, unless you do a thick 'sphere' of solid leaves to have it stick out of.

It's a good technique to use too, Valve does it with the hedges in L4D2 Parish map. You have to crawl inside the floating leaves to see that it's a solid mesh inside, but it has good depth in the tex and they look pretty realistic.

A good way to fill out the tree.

I'd suggest some lumps, or burls around the bottom of the trucnk, clumps of 10 tris here and there could give it alot of shape. (like half spheres), just stick them right on top (floaters) instead of building them in.

Jessica Dinh

Aww, I got to your post too late Baddcog! I'm almost done with the diffuse texture, or at least to where I'd like to post here for feedback. But this isn't the last tree I'm doing, and that solid sphere of leaves idea will probably come in handy for another tree I think. Also I googled burls and wow! those things are cool! They certainly would add some great shape to a tree and I will probably add them to my next one.

As it stands, I just deleted that floaty branch for this prop, as nobody's really gonna miss it except for maybe me and the concept artist ahaha.

Diffuse map, 256 x 256:



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Max render, leaves coming soon ^_^:



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Critique welcome!
Jessica

Jessica Dinh

Here's my tree! ^_^

Materials:



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UDK renders:



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Alright, I'm gonna take a break for some 2d. But I will be back with another tree soon

-Jessica

Jessica Dinh

Here's a better shot where I fixed the spec. Bark isn't shiny anymore lol.



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Jessica Dinh

Mmm, 2d can wait . . . haha. Here's another tree, concept by Nick de Spain:



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470 tris. Keeping under 500 in order to use a 128 texture:



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Critique welcome!
Jessica

Jessica Dinh

Here's the texture! 470 tris, 256 x 256 spec, diffuse, nrm. Critique welcome!



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Joopson

You best be making a whole environment to put these trees in, because I want to walk around in it.
I like the style - the only thing is that this tree only looks like a tree if you see the roots - otherwise it looks more like the gallows, or something. Maybe add some minuscule branching from the tree, with a few leaves? Something that will help it read as a tree.

Jessica Dinh

Oh that's a good idea about adding little branches! I think I could manage to squeeze some into the UV's XD And these will be in an environment, actually in-game! But you won't get to walk around them because this game takes place primarily on an airship and you can only see these trees from a distance. *sadness* ahaha

Jessica Dinh

Hmm, yeah I think I could punch the intensity on the normals a bit more, and after I add some branches to this tree I will take some shots with lighting! Thanks!

Jessica Dinh

Update! Thanks for all the help guys! New tree coming soon.



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Baddcog

Normals depend on a lot of stuff imo.

They show best of course when you have a large area, covered with small details. Also depends on light. Then there's in game, where you see the effects much more stringly than a screen, you can move around and see the bumps, from a screen the highlights/shadow could be seen just as diffuse.

Jessica Dinh

Ok, so apparently my director said that this tree is going to be seen from so far away that those little branches I added aren't going to do anything ahaha. So I made the branches BIGGER and also added some more pods Hopefully now it is reading better as a tree!



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1192 tris

AlexLegg

I like the look of these trees, keep 'em coimg!