How to make particles in Yafaray

There is a lot of options to make particles but technique is depending on which effect do you want to get.

Grass in Yafaray

1 Technique

This is the simplest technique and it don't take longer than some seconds to get renderable particles in Yafaray.

1. Select all object (key ”A”) and delete them (”X” or ”Del”)2. Add (”Space”) → Mesh →

Plane3. Go to object menu (F7) and

to particles tab 4. Click ”Add New” and change

Particle system from "Emitter" to "Hair" and ”Amount” under “Basic” to 2000 like on the picture

5. Change in physics settings ”Normal” value to 0.16. Change ”Random” value to 0.1 as well7. Than in Global effects change ”Acc” - X and Y to 0.01

8. Go to Editing (F9) and in ”Modifiers” click ”Convert”9. Duplicate this object (”Shift+D”) and move it close to first plane (like on picture)

10. Now we have simple edges as mesh instead of particles, so now go to edit mode and select all vertices (”A” key)

11. ”E” → ”Only Edges” → ”X” key and value 0.01 , it will extrude your vertices and move along X axis 0.01 BU (Blender Unit)

12. Now mark second particle mesh(RMB), go to edit mode, and extrude all edges by ”Y” axis.

13. Go to object mode (”Tab”) and move mesh over the first one, but don't move them exactly on the same place, so they look like more random particles. (in my case it was -0.1 XY)

14. Now add a camera (”Space → Add → Camera”)15. Mark one of meshes with Shift+RMB and press

Ctrl+T and choose ”Old Track”16. Now mark just a camera (RMB) and move away

from object like in the picture.17. Now, we have to put some material on our

meshes, so we mark one of converted particle object (RMB) and add material in ”Shading” menu (F5) → Add New

18. In ”Links and Pipeline” Change name of material to ”Grass”

19. Now we have to split window to get Yafaray material setting (RMB on horisontal line between button and 3d view an ”Split Area”)

20. Change window type to python scripts and ”Scripts → Render → Yafaray export”

21. Change ”Color” to something like #2D9D27 in Hex color code

22.23. Change ”Transparency” and ”Translucency” to 0.2

and click Refresh Preview to reload Preview material

24. Now, mark the second grass mesh (RMB) and click on those small arrows next to ”ADD New” button and choose ”Grass” which we created

25. In ”Links and Pipeline” press 2 button next to ”MA:Grass” and confirm question ”Single user?”

26. in Yafaray Material settings press ”From Active object” button and change color to brighter and less colored like #65BB60 and refresh preview if you want

27. Now mark the first our plane wit particles (as you know particles as system ar not renderable, so you don't get edges of particles on render ;) ) and add new material

28. And you do the same think like in our first case but dont touch transparent option and translucency, just change color there ;) to dark brown

29. In Yafaray settings click ”Settings” button and press ”Use AO” (Enables Ambient occlusion) change AO distance to 10 and BG color (black as default) to brighter, like light blue

30. Change AA samples to 4 or higher (so you get smooth pixels) and press ”RENDER” button.31. Now wait and hope for good result ;)

Here is my result

Second and more advanced technique with better result ;)

1. Delete all objects on the scene2. Add new plane and go to particle tab and add new particle system3. Change system from “Emitter” to “Hair”4. It would be just fine with Amount 1000 so change Normal to 0.1 and “Random” lets say to

0.05

5. Now you have to make your strands for particle system so you go to the second layer (key 2 on main keyboard layout - not numeric) and add new plane

6. Go to edit mode of this plane and scale it along X axis 0.1 times 7. Ctrl+R and rotate mouse wheel

until you get 4 cuts (you can just type 4 under cutting)

8. Mark these 2 vertices on top and choose sharp falloff (O key) and scale them by X axis to zero (you can adjust the affect of modifier to mesh by spinning mouse wheel)

9. Than, you can add some realistic shape to grass, (it will be better looking) like ctrl+r (apply) in the middle of plane along axis Y and than move more by Z axis like 0.3

10. Scale the top of mesh by Z axis also using falloff, and now we can scale whole the object along Y axis twice and press N button to know the name of the object, in my case the name is Plane.001 so remember the name first (under time you can set smooth on object so its smoother ;))

11. Rotate the plane 90 degrees clockwise so the sharp top is pointing 3 o'clockNOTICE: If you don't want to map your grass into UV mapped image you can jump over to 12 stepa) after that you are done with modeling grass strand you can put UV texture to make some scratch of the surface so it looks more realistic, so I did in Gimp new image 500x500 px and rendered clouds on highest detail and smallest size and than added motion blur – 0 degrees an 200 greed (just if someone is wondering ;) ) and at least colorized and changed contrast/brightness 20/-20b) in edit mode you press U button and unwrap → projection from view (camera must be directed from top )c) load image you prepared and pin it by pressing P button in UV editor

d) don't forget about creating material to the object, adding texture in texture input and than in material tab and “Map input” box change mapping into UV instead of default “Orco” (otherwise texture will not be rendered by Yafaray)e) you are done now, so you can now continue with particles

12. Go to your 1 layer, mark the particle plane and change in “Visualization” box from “Path” to “Object” and set Object name (in my case) Plane.001

13. You can make these two layers visible by holding shift and marking first two layers. Mark (RMB) your grass strand and move along X axis to adjust particles position on the plane.

14. When you are done with that it's just to add some “wind” so that your grass looks more realistic, so add new lattice and scale and move over plane like on the picture

15. Set lattice points of W direction to 10

16. Now, mark your plane with particles and in “Modifier” box convert particles to mesh

17. Mark all of grass strands and ctrl+j (join selected meshes)18. Now you have to convert them to one mesh, otherwise we get error

when we put apply to some modifiers (like subsurf) which says: “Modifiers cannot be applied to multi-user data”

19. So you have to convert them alt+c and choose “Delete Original” (the second option)

20. Now you can put subsurf (if you want) but you have to add modifier “Lattice” and define lattice object (in my case the name is simply Lattice)

21. Now, mark lattice and go to edit mode, mark vertices in top of the lattice and move them lets say along x axis with sharp falloff enabled

22. you can now duplicate your object (shift+d) and go to edit mode and rotate all meshes 90 degrees to make not only more particles, but also add more random particles.

23. Because grass in forest isn't just grass, we have also some weed and flowers, you can put them as object to your plane with particles by changing name of object (in my case its “Flower”), secondly convert particles to mesh, join them, and convert them to mesh and add lattice modifier (the same thing like in steps 16-20)

24. And now, to the materials, (don't forget about camera ;)) I used AO with 10 distance and light blue BG and AO color and sunlamp (yellow of course) angle 2

25. And just to press “RENDER” button and its done

Good luck

My result: