Render Color And Alpha Attributes

[kubabuk]

How can I render of my geometry with color and alpha attributes aplied from primitiveSOP? I tried to use attributeSOP and rendame Cd to diff but it does not work...

Thank you

[kubabuk]

I think I got it. It seems to work without renaming with VEX layer surface material but I cant make alpha work with VEX constant. I renamed attributes Cd -> clr and Alpha -> alpha

kuba

[Jason]

Hey there,

Did you read this page? VEXUsageTips

[kubabuk]

Nope, I apprarently ovelooked that at wiki. Thanks a lot

[symek]

Czesc Kuba,

generally the easiest way to deal with that sort of problems is to mouse over parameter name in shader to see its internal name. For plastic shop these are diffr diffg diffb. This way you you easly determine what to override. AttribCreate -> diff for example)... never mind. Jason has just pointed out knowledge base...

cheers,

SY.

PS Did you manage your alpha/texture problems?

PS2 I won't be in London for sure even though I fixed my passport issues. (After all I work on online this day). Maybe you can make some report on this meeting?

[kubabuk]

Czesc Symek

Overriding attributes is still new to me, but I can see, that feature is so powerful!

When it comes to alpha problems on sprites I still cant get rid off white 1px fringe around the shape. I don't know but in 3dsmax the problem was similar with tiffs, but with png textures alpha worked perfect. I havent check that yet in H. but for me tiffs suck.

If I manage to find a while I definetly put some report here or on forum3d.pl (that would be a good way to awake that somnolent forum)

kuba

[edward]

I don't think we can help you unless you posted an example .hip file along with your sprite image.

[symek]

If I manage to find a while I definetly put some report here or on forum3d.pl (that would be a good way to awake that somnolent forum)

O yes! Wake them up!

SY.

[frogspasm]

I'm having a seemingly related problem in H9.

I'm trying to render out particle sprites using the particle's color and alpha.

The Mantra:Sprite Procedural shader that mantra uses to render the particle is a geometry shader, and doesn't seem to have any color variables that I can drive.

Would I have to create my own geometry shader with VEX?

Thanks!

~Mike D.

[nnnnn]

From the Wiki:

Q: How do I render the color (Cd) attribute?

Use an Attribute SOP to rename Cd to the corresponding shader parameter. For most default shaders, this is diff.

In case you are using the Mantra: Sprite Procedural node you also have to specify which point attributes should get copied to the sprite. This is done by adding the point attribute name (without the Dollar sign, separated by Whitespace) to the Mantra: Sprite Procedural's Attributes field.