This way is also useful for any kind of area on grass, asphalt or whatever:
(http://imageshack.us/a/img33/6782/tutodirt1.jpg)
(http://imageshack.us/a/img542/9515/tutodirt2.jpg)
(http://imageshack.us/a/img692/4948/tutodirt3.jpg)
(http://imageshack.us/a/img10/369/tutodirt4.jpg)
(http://imageshack.us/a/img651/8371/tutodirt6.jpg)
(http://imageshack.us/a/img706/1456/tutodirt6b.jpg)
(http://imageshack.us/a/img600/4557/tutodirt7.jpg)
(http://imageshack.us/a/img843/7351/tutodirt8.jpg)
(http://imageshack.us/a/img801/220/tutodirt9.jpg)
(http://imageshack.us/a/img822/1537/tutodirt91.jpg)
(http://imageshack.us/a/img692/5836/tutodirt92.jpg)
(http://imageshack.us/a/img41/1329/tutodirt93.jpg)
(http://imageshack.us/a/img690/3385/tutodirt95.jpg)
(http://imageshack.us/a/img32/1615/tutodirt96.jpg)
(http://imageshack.us/a/img259/4192/tutodirt97.jpg)
The last step and very important is to create a fake (or not fake) BUMP texture, named for example "grass_bump.tga". It can be like this, a blue texture with black Alpha Channel. It won't change the grass at all in dry but it will when rains, looking darker and realistic.
Create as well the shader file, let's say "grass.shd" with this code on it:
bump
{
map = grass_bump.tga
}
(http://img690.imageshack.us/img690/3623/tutodirt100.jpg)
fantastic work! great clear images too. whats next? skid marks, maybe track true puddles?
i had an idea today for how to make skids very easy i try it later and when it works i will show you how to do it ;)
Yes, there is a problem with that... :(
But I think it is a bug, because Piboso's guide is clear:
For tyre marks, a second texture can be defined using Opacity channel and a secondary UV mapping. Textures with alpha channel will be drawn with alpha blending, while ones without alpha channel will be drawn with multiply blending
So we are allowed to use alpha channel, but if it is used, the part is not darkened when rains... In the first betas, there was a way to darken manually the textures using a file, but it is not used anymore.
We should ask him for a better idea or a fix
if you are willing to sacrifice some texture quality you can use one channel and make a custom texture with both grass and dirt then use the UVW map manipulation and gizmo drop down (+ symbol next uvw map modifier) to rotate the texture to fit perfect.
There is no need for that :)
If you use bump map for the grass, the texture is darkened when rains. There is no need for a real bump texture, it can be a fake one, all blue. But it is better to use a good one, which makes the grass look a lot better
UPDATED TUTORIAL WITH THIS STEP
could you please give me that texture you made there?
Here:
http://www.mediafire.com/view/?cn6r2d2qnne7q04
thanks aritz