Street Scene trouble with particles

I am following this tutorial on YouTube about doing this street scene that he is adding rocks to the scene using particles
they are on a separate layer. Putting them into a group (more than one rock) selecting only one of the rocks then going
into particles and selecting hair. I want the rocks to be spread along the ground.

Not into that in the pic. What did I do wrong?


Hi,

You have to add your particle system to your ground object, not to the rock object. And set your particle render type to “Group” (or “Object” if it were only one object), then set “Dupli Group” to your rock group.

Good luck,

Luca Rood

Luca thanks for the help

Now I have been trying to do the twig and I did select the twig and the ground added the twig to the vertex group then went to particle, in the render I have it in object but not in group I have been trying to get it to the vertex group and I can’t.

Please help.


“I have it in object but not in group” - in Object mode Ctrl-G will make group of selected object(s) which will turn up in Particles tab. Name group on T panel.

eggo I did try that and at first noting happened then I went and redid it. Then I got the seeds but not the twigs.

Here is the blend file http://www.pasteall.org/blend/30671

Thanks for the help

I have no idea which tut you follow but i have feeling there are couple of things which needs to be straightened.
As i get it - you try to make tree using particle system for twigs on some trunk which is named “twig”?

Particle system:

  1. can use Objects as particles - this should be Group of objects if you want some variety and can be set in Particle system - Render - Object or Group. By selecting objects and Ctrl-G you create such group.

  2. Particle system “sticks” to the whole object by default - one way to change that is to set particle local density using vertex group - you do that by Weight painting object which generates particles - as soon as you start Weight painting vertex group is created if there was not one. Name of this Vertex group is then set in Particle system Vertex Groups Density field.

So that you could have had 2 things named “twigs” - twig object (or group "twigs) and Vertex group for twig density which also can be named “twigs” belonging to “trunk” object (if that was a tree).

Since i have no clear idea which is what in your file i guess i managed to add trunk as twigs to the trunk :D.
http://www.pasteall.org/blend/30673

You need to set Origin for the twigs to be at the beginning of it - it is used to connect particle object to the emitter and you do not want to be it in the middle of the mesh. Also, initial rotations are important - particle objects need to be rotated -90 deg on X and rotation Applied to be “normal”.

Thanks for the help

this is the tutorial that I am following

have you tried the grease scatter add-on? basically you make a group of debris objects, then you use grease pencil to scribble in where you want your debris to be concentrated, and it calculates where they are most likely to fall and sets them there. It does a pretty nice job, too. I think they used it for Tears of Steel. btw, I don’t think it will scatter debris on an open plane. there need to be some kind of corners and other places where debris might accumulate.

I did addon the grease scatter but I got an error. I was able to get the particles to work but I am still trying to figure out some things.

Thanks for the help guys. The other objects I will do it differently.

Ok, so that is a ground Plane which has several Particle systems added and several Weight groups to distribute particles painted on - each to his own particle system.
“twigs” is just one object, not a group. Hope this helps a bit.

eppo you were correct it wasn’t as a group. But after playing with it for a while I finally got the particles to work only part of the time. Anyway, I did the grass and twigs individually. But when I did the leaves it worked.

I rendered this in cycles which turned very noisey and no light except for a spot.

The image wouldn’t upload so I am choosing photobucket to show you.

It is the exactly same image as blender render. Why is the cycles so noisey and there is not light like in blender render.


I might add a broken bottle in this as well. Next is the textures and materials.

Well, have you done anything about lights and, especially, materials before switching to Cycles render engine? Any render parameter tweaks for Cycles?

Being a Noob with this I mistakenly thought I could do all the textures, materials with cycles. I have done the lighting for it but not any tweaks on the lighting to speak of I was doing another model and I did it with cycles and I started to tweak that and I saw that the noise was no longer there. It is only two wine glasses but I will work on that with this scene.

Well, have you done anything about lights and, especially, materials before switching to Cycles render engine? Any render parameter tweaks for Cycles?

This might be a stupid question but why do you need to put in the materials before going over to cycles. Watching some youtube videos I noticed people put the materials and textures while in the cycles render. I just assumed you can do it that way.

This is the blender render that I have done with this lighting effects. I have the key light as the sun and a spot light almost directly above and slightly toward the back. I still have some tweaking on the spot light. I want that shadow gone from behind the barrel laying down. Any suggestions would be appreciated.


You certainly do not need to put materials ahead of switching to Cycles; what you might need is set Render Samples higher for the preview (final) render - otherwise it will be grainy. By default this is 10 only; if you have Nvidia graphics you can set it much higher while getting much better view Same can be done while using CPU but it’ll take a bit more time to render.

Lights in Cycles behave slightly different from BI - mildly put; if you want shadows i’d suggest orienting Sun and setting it’s size less than default 0.1.
Expect to rise strength of Spot lights significantly.

You can do all materials/textures in Cycles; in fact it’s easier than in BI - if you’re used to Cycles Node system.

Thanks I will try that