Indigo Renderer Forum

Headroom wrote:Yes. Don't use hair

Use a simple grass object modeled in blender and then use the particle system to instance it. StompinTom posted this little tutorial ages ago and I am not even sure if it still opens up in Blender that does exactly that.

http://www.indigorenderer.com/forum/vie ... =19&t=8846

The hair system in Blender is specifically tied to the strand renderer in Blender and I don't think, it can be used with any external render engine, be it Indigo, Luxrender, Yafaray etc.

Once you've successfully create the first grass you can use with maps to distribute it unevenly etc. works pretty cool actually.

aleksandera wrote:It would be nice to have something like this in Blender exporter
http://xaotherion.deviantart.com/art/Lu ... -178646164

StompinTom wrote:With instancing you can use size and density maps as well, something which is incredibly useful.

Polinalkrimizei wrote:Blender spreads the grass meshes around the surface as you wish, e.g. controlled by a density map. Blendigo exports the meshes as instances afaik, and most of the time three or four light meshes are enough.

StompinTom wrote:

Polinalkrimizei wrote:Blender spreads the grass meshes around the surface as you wish, e.g. controlled by a density map. Blendigo exports the meshes as instances afaik, and most of the time three or four light meshes are enough.

Yes, that's correct. It requires you to switch to Blender Internal to reveal the texture settings, though, something that the Blendigo devs may want to look into freeing up. Activating Indigo hides a lot of the texture functionality that Blender otherwise has.

  <scatter>
    <name>the scatter</name>
    <geometry_uid>1000</geometry_uid>
    <material_uid>3000</material_uid>
    <num>1000</num>
    <shader>
           <![CDATA[   
def evalScale(int index) real :
  0.1 # 0.1 * (0.5 + gridNoise(real(index)))	]]>
    </shader>
    <target_object_uid>2000</target_object_uid>
  </scatter>

CTZn wrote:

StompinTom wrote:

Polinalkrimizei wrote:Blender spreads the grass meshes around the surface as you wish, e.g. controlled by a density map. Blendigo exports the meshes as instances afaik, and most of the time three or four light meshes are enough.

Yes, that's correct. It requires you to switch to Blender Internal to reveal the texture settings, though, something that the Blendigo devs may want to look into freeing up. Activating Indigo hides a lot of the texture functionality that Blender otherwise has.

In the case of random scattering over a surface, the particle system could be translated to an indigo_scatter node, density(/size iirc) texture/shader included.

The density/particle count would be preserved but the particle placements would be different. Exports blind fast.

edit: I checked and the instance size does not seem applicable using polygonal meshes but parametric surfaces.
edit2: actually the node name is scatter.
edit3: my XML reference, there's no further data required to scatter 1000 objects over a surface (using a shader):

Code: Select all

  <scatter>
    <name>the scatter</name>
    <geometry_uid>1000</geometry_uid>
    <material_uid>3000</material_uid>
    <num>1000</num>
    <shader>
           <![CDATA[   
def evalScale(int index) real :
  0.1 # 0.1 * (0.5 + gridNoise(real(index)))	]]>
    </shader>
    <target_object_uid>2000</target_object_uid>
  </scatter>

StompinTom wrote:

CTZn wrote:.../quote]

This would be something that would be extremely useful with PyNodes within Blender! If we could have some Indigo material nodes with things like scatter, ISL textures, etc., it could really simplify / speedup things like particle export / distribution.