by melvin » Fri Jun 14, 2024 9:55 am
It is possible to plant small objects like bushes, grass & rocks on a landscape just as in ages like the Cleft or Ercana. The process is actually quite simple & is speeded up by using the weight paint. Objects like in the image below can be added in as little a five minutes. I've been doing this in Western Teledahn so I know it works. You can even make the objects fade at a distance using the texture filter just like in Cyans ages.
Firstly the ground plane will need to be subdivided a reasonable amount of times as each face will emit a particle as an object. The vertices need to be selected & then added to a new group; this is important as it controls the weight paint. If you want to add different objects then use the copy group option & give them separate names. Now you will have two independent weights both using colours blue, green, yellow & red. These are strength colours & control how dense the objects are grouped together in any particular place. Blue is off & red is the maximum.
Next you need your objects as in the image below. Note the obvious that they are rotated 90 degrees along the local Y-axis, then notice the not so obvious; where their centres are located. Not just at the base of the objects but in the centre of that grid where the default cube is when you start blender. Once objects become particles you can move these & cause every particle on the plane to move or even explode from the scene.
Now select the plane & add a new particle system; you will need more than one system if you are planting different types of objects. Lots of new options appear but don't panic, you only need a few of these, & most of them can be set to a default & left alone.
Particle System window, set it to emit Hair, Faces & Jittered then press the Even button. The Amount depends on the objects, a high value which may be in the thousands for grass, & a low value for rocks, about 30. The last option is P/F default zero or automatic. The higher the value the more the particle objects will try to avoid faces that are already emitting a particle. Left at zero objects of various sizes will be generated on top of each other; like small rocks hiding inside larger rocks.
Visualization window need to be set to object; & then the name of the object to be displayed as a particle. The Disp setting should be set to the max of 100 although you can alter it.
Physics window set to Newtorian & Midpoint, also set the rotation to Normal; this will make each object align itself with the ground face following it's Z-axis. You can alter the ground mesh in edit mode & the objects will adjust to their new locations once you exit edit mode. Lastly is the initial velocity Normal & Random settings. These work with the Extra window Size & Random settings so you will have to alter them both to see your particle objects. The Random button will randomly alter the objects sizes; making rocks & grass look more realistic. When you start to scale your objects up to size, it will soon become apparent how important the ground mesh subdivision size matters. If you have small subdivided planes & large rocks they will overlap, but with grass this may be what you want in certain areas, so some thought is needed.
Lastly the Extra setting, not including the Size & Rand values. The Seed just alters the output & can be experimented with to get the best result. The most important setting here is the Vertex group Density setting. This must be set to the vertex group or groups you created earlier & connects each particle system with their own weight paints. Once you have connected this you will need to go into weight paint mode, clear it with blue & the add a bit of paint where you want your objects to appear; the stronger the colour the denser the groups of objects.
Once you are happy with what you have created you will need to convert the particles into separate objects. Make sure the ground mesh does not need to be altered, as the objects will not follow it once the particle emitter is turned off. It has to be turned off, along with the vertex groups, to get your age to export. First press then Conv button found where blender adds Modifiers; the particles have now disappeared from you ground mesh. Next delete the Modifiers & your vertex groups from the ground plane. Now go to the objects in the centre of the blender default cube grid. Set to single use the Data Blocks, Materials & Texture; if you don't do this strange things may happen when you duplicate these particle objects. It's also a good idea to remove the date blocks off the new objects created with the convert button. The easiest way to do this is to select one object, then select, linked, material which should select all the objects. Then join them all the together.
That's it!, your age should now export Bare in mind this is not an exact science. In edit mode you should remove the doubles from the vertices just in case. Also you should inspect objects in wire frame mode where no doubt you will find places where smaller objects have been created inside larger ones. Also note that you will be adding allot of vertices to your ages overall vertices count. You can go a bit crazy with the grass as long as you use the texture filter to control the render distance; about 0.8 rather than the default 1.0.
- Attachments
-
![Planting Grass.png](./download/file.php?id=2906)
- Planting Grass.png (696.42 KiB) Viewed 7066 times
-
![Particle Settings.png](./download/file.php?id=2905)
- Particle Settings.png (184.05 KiB) Viewed 7066 times