Help with weird Particle Scatter please Tweet

[Humpti]

Hi,

I'm actually a Rhino-Plugin user and evaluating the Blender Demo, just because I like Blender and to add another tool. But I' still a novice.

So, I was looking for 'The Grass Essentials' and tried to recreate his workflow with a simple proxy object.
It works fine, but I don't understand the distribution of the grass on the purple object. And I can't change it. I'd like to have an even distribution like on the other objects.

Strange Purple Scatter

I have this Scene (with tutorial objects from Phantom Scatter (which is great for Rhino) (I hope it's ok to use them in this scene, Guus?)) if any advanced Blender User would be so inclined to have a look at it ...

ScatterTest.zip

Scatter Test

(440.82 KiB) Downloaded 204 times

Thanks
Philipp

[kubicki3d]

Hi,
I've made some changes and added some comments in the file, take a look. I'm pretty sure this could be done in many other ways and I'm very curious what other users may come up with.
Cheers,
Szymon

[Humpti]

Hi Szymon,

I can't thank you enough for your help. I could reproduce/understand most of it.

What I don't understand is why you rotated the grass-meshes. It must be rotated so that you can have the particles set to rotate instead of global, but I don't understand the inner reason for having to do so.

I set the dupli objects to draw as /bounds. Good idea. Are the particle objects instances for Octane? I wonder, because it takes so much time to transmit the scene to the server.

A little side question I have, I didn't find any option to convert the normal materials to octane materials like in Rhino. I wanted to buy the Grass Essentials, but thought Octane would help a little bit in converting.

Cheers
Philipp

[kubicki3d]

About rotating the dupli object... This may sound silly, but honestly I don't understand this either Anyway, after some trial/error testing I found this helps when I want to set the initial rotation to Normal - which gives nice control over rotation randomness. I've never really given it much thought, but since it works, I keep repeating this solution in every project. With Grass Essentials you will get particle systems set up by proffessionals, so you can be sure about their correctness.

As far as I know, particles with dupli objects set as Scatter are VRAM-friendly instances for Octane, just like Alt-D duplicates. The scene transmission time might depend on total amount of particles, or it may have increased because I used "real" particles instead of children, or because I added another particle system to the scene. I'm not quite sure, maybe someone more experienced could explain this.

I'm afraid there is no option to automatically convert materials form cycles to octane. But usually for foliage a simple mix of diffuse and glossy shaders does the job (one image texture + a couple of color correction nodes to control diffuse, roughness, specular and transmission). One note - it is a good idea to group single leaf textures into one big image, just like Enrico Cerica did in his River Side project: http://www.3dtotal.com/index_tutorial_d ... Y6NA_ntlBe

Cheers,
Szymon

[Humpti]

Thanks Szymon, you really helped me a lot!

Yeah, what works works. Sometimes things changes from Blender version to Blender version without knowing why, so it's ok to simply use it like so.

Once in Octane it goes really fast. Maybe there's some of way of caching stuff? I'll have a look. I think I read something about it, but I have read so much recently

The tutorial is great, thanks for the link. It probably is safer to recreate the materials for octane anyway.

Cheers
Philipp

[Phantom107]

Humpti, please be aware that I don't get notified when you post something related to me. So please post in the Phantom Scatter topic or notify me of the topic (through e-mail or PM). I stumbled upon this one by accident, I was actually searching something unrelated.. So is the problem fixed in the meantime?