Texture Alpha for Transparency in Depth Pass

[ChrisZ]

Hi there,

i'm trying to do a depth pass of my scene which features some textured grids.
The textures have alpha channels that i'm picking and i'm linking those to the transparency of the grids phong shaders.
But when i do a depth pass with xsi's built in pass, it does not render the transparency of the grids.
This is due to xsi adding a constant material override in the depth pass.

I did a test scene that shows the problem, screenshots attached.

I've searched the net for some time now but could not find a solution.
I'm sure it could be done with ICE but i'm a total noob with that.
In maya it's just one klick in the camera ppg... darn it, i never liked maya.
Anybody?

Thanks,
cheers,
Chris

[caledonian_tartan]

you need to do the picker thing on the Depth-Material.

to create your own depth material you could use the scalar_state node set to ray length.
in my example i go with the sprite node to involve the alpha.

alphadepth.jpg

[ChrisZ]

Hi,

thanks to caledonian_tartan for the suggestion!
sorry for my late reply, had to switch to another project for a few days.

There are multiple objects in my scene that need alpha in the depth pass.
So i need to create an empty pass and in that pass i use your "Depth-Material" on all of my objects, right?
I'll try that right away, thanks for the rendertree!

cheers,
Chris

[caledonian_tartan]

ok. in this case i suggest this:

to use only one depth material:

the annoying thing now is, to put a texture map on all the objects that use a texture.

instead of the image node in my tree, connect a Color_Map_Lookup to the sprite matte and set it to texture map.

[ChrisZ]

I'm not sure if i got you right.

to use only one depth material:

Do you mean by creating a material for the "Background_Objects_Partition" in a new pass?

the annoying thing now is, to put a texture map on all the objects that use a texture.

The textures are actually already set up on the objects.
If i render a simple color pass everything works fine with the transparency.

Do i add the "Color_Map_Lookup" to the "Background_Objects_Partition" Material or is object specific?
Or did i get it all wrong in the first place?

thanks,
cheers!

[caledonian_tartan]

i think you almost got it.

the aim is to use only one depth material and look up the alpha from the objects texture map.
don't confuse the texture map property (what you need to set up for alpha-depth) with image textures used for all the materials in the main pass.

so, a good place to apply the depth material is on the Background_Objects_Partition, yes.

the "Color_Map_Lookup" to goes on the "Background_Objects_Partition" Material, the depth material, yes.

check out the scene i attached, including a default and depth pass. (you probably need to relink the two texture files...)

DepthAlpha.zip

[ChrisZ]

Thanks for the scene, but i forgot to tell you, i'm still on v.2012 so i can't open it.
Is there any chance to save it in a "legacy" format for you or do another screenshot?

I understand what you're doing which is exactly what i need and it seems to be an elegant way.

Thanks!

[ChrisZ]

i'm confused about the settings in the lookup node.
it seems like it wants me to select a specific object to pick the map from and not take all maps on all objects in consideration.

if i render i get a black image which i can turn white by changing values in the change_range node.
i think this works like the density/contrast sliders in si's own depth pass material, right?

but something's still not working right..
raydepth should be set high enough, it works fine for the default pass.

cheers!

[caledonian_tartan]

the "color map lookup" node looks up the texture maps.
the texture maps need to be set up manually. they are not the same as the image textures you use in the default pass. it's a property.

(unfortunately) i only have 2015 over here.

alphadepth.jpg

[ChrisZ]

thanks for the screenshots.
i really need to do a fresh clean scene and try to replicate your scene.

i applied a texture map to the uppermost grid in my scene and set it up, but i still can only select weight or color maps in the lookup node.
shoudn't be texture maps available as soon as i create one on an object?

thanks a lot for your help so far!
i've to leave it for a few hours now but i hope i can get back to you later to sort things out.
cheers!

[caledonian_tartan]

yes, the map should be available if there is a texture map on the object and the material asking for the lookup is applied to the object.