Peluche Were-Rabbit

[katkase]

Hello,

I wanted a plush look for my werewolf rabbit, but to get the hairiness I wanted (the one you can see on the face for example…) I had to set the number of hairs for the body to 20.000 (*100 childrens = 2.000.000) which gave me the infamous “out of memory” error during the render (I got only a 8 GB graphics card… )
I read about the possibility of splitting render into render layers but the rabbit body is currently a single mesh so I decided to postpone this work when I can do retopology to get rid also of the 50.000 polygons more than necessary

PS: the hair is not combed

[capa14]

Very interesting and awesome fur!
The nose looks like from a pig though…

One thing you could try to avoid crashing is reducing the Tile Size (under Performance).
The smaller the tile size less memory it will need to render the a tile. Hopefully not crashing anymore

[katkase]

Thank you, very good info

I set the tile to 512 x 512 because this way my GPU was rendering faster. However I’m not entirely sure that my “out of memory” error comes from this, because it happens before rendering starts, during initial calculations.
I’ll try!

[katkase]

Ok, I did some tests and I understood were my “out of memory” error comes from

The Cycles render process when particle system settings are present goes through these steps:

1. Synchronizing objects
2. Updating BVH Mesh - Building BVH
3. Updating BVH Mesh - Packing BVH triangles and strands
4. Updating BVH Mesh - Packing BVH nodes

here it stops with error

I found that leaving the numbers of hairs to 20.000 (with 100 childrens) and changing the steps parameter (in my case from 5 to 3) in the render section of the particles not only ends regularly the process but also speeds up

from the BlenderWiki:

“Steps
Set the number of subdivisions of the rendered paths (the value is a power of 2). You should set this value carefully, because if you increase the render value by two you need four times more memory to render. Also the rendering is faster if you use low render values (sometimes drastically). But how low you can go with this value depends on the waviness of the hair. This means 0 steps give 1 subdivision, 1 give 2 subdivisions, 2→4, 3→8, 4→16, … n→2[SUP]n[/SUP].”

So, steps set to 9 means 2[SUP]9[/SUP] = 512 subdivisions, which is a ton of geometry you create that has to be organized by the BVH core before rendering.

The size of the tiles instead only affects the rendering speed for what I know.

[capa14]

Humm i see the hairs particles work different even before starting to render the tiles.

I had a problem before while rendering a realistic car where when I set the render tile to 512 it would crash midway, but setting to 256 would allow to finish the render. So that’s why I supposed that.
I also have a 8gb graphics card, and 16gb of Ram.