material performance issue

[Simon.Anderson]

Hi,

 

I'm getting a big slowdown (when 50,000+ cubes in the scene) when using blend material settings on ANY static object - here's the line causing the issue in the mat file: 

 

<blend src="src_alpha" dest="one_minus_src_alpha"/>

 

 

here's the full material that can be used as an example:

 

<material name="BlockModel" parent="mesh_base">
     <options depth_mask="0" post_deferred="0" post_scattering="1" post_refraction="1" glow_mask="0" parallax_mask="0" two_sided="1" cast_shadow="0" receive_shadow="0" cast_world_shadow="0" receive_world_shadow="0" receive_translucent="0" />
        <blend src="src_alpha" dest="one_minus_src_alpha"/>
  <parameter name="diffuse_color">1 1 1 1</parameter>
  <texture name="diffuse">Block.png</texture>
</material>

 

 

can anyone tell me why this is the case?  I would like to set the alpha value of a material but without the blend information it doesn't seem possible.  Is there a work-around for this?

 

 

 

Thanks,

Simon

 

[ulf.schroeter]

Rendering transparent objects is by principle more complex as it requires object depth-sorting in each frame for proper rendering results. With 50.000 objects this might take some time. Also some other engine-internal optimizations like e.g. better draw call batching might not be possible for transparent object surfaces.