Hello all
@Darwin:
I'll try to explain how I've done trees in the video.
(sorry if I'm late, hope you'll read that)
I didn't understand if you need to know how to create a tree or how to spread it over the terrain
so I'll explain both XD
Remember that my advices are the advices of an absolute beginner,
so be careful (lol)
Look at the picture ..
As you can see the tree model is composed by a trunk(Orange) and leaves(green),
two different models then.
The trunk is just a simple extruded cylinder and mapped with the left texture.
For the leaves, first you create a quad (2 triangles), then apply the leaves texture (Right).
The quad is then cloned, crossed, rotated and scaled randomly about 30 times.
That means just 60 triangles per tree.
The 30 quads are merged using a boolean operation (add), that "creates" a single model for the leaves.
In my case, textures are handpainted using simple colored pencils.
The leaves background is not white, but transparent. I made it white in this picture cause
it's a jpg image, but in the "engine" it's a 512x512 .png image.
About rendering a lot of trees... there are many ways to do it.
It depends on how your engine works.
Mine is not a quadtree. The terrain is splitted into what i call "clusters".
Pieces of terrain (16x16 vertices) that are culled based on camera position.
Every cluster can have or not have a tree "over it" (it's random).
So when I render the terrain I draw only trees that "exists" in a rendered cluster.
The engines does :
- is the cluster visible? yes - render it - There is a tree over it? yes - render it.
- Is the next cluster visible? yes - render it - There is a tree over it? no - check the next cluster
And so on (I have a strange method to explain lol)
Since I use a 1280x1280 heightmap, I have 80x80 clusters(6400), but the engine
only renders 100 per frame, so let's say about 40 trees per frame.
(but you can choose the percentage, I use about 40%).
Of course a single tree is placed with random scaling and rotation, to give the illusion of
a different model.
You must also check the height of the terrain when placing the tree.
If you look at the model picture, you can notice that the base of the tree is under the "zero" plane.
This prevent the base "come out" the terrain (not sure it's correct english lol), a bug
that I find in many commercial games.
OK, I know it's not really clear.. but I hope you can find it useful, or
at least it gives you an idea.
It was not easy for me write for so long in english and I would have been more clear :D
As always .. sorry for my english and See you soon :)
