How can we get the usage (mask/transparency) of the alpha value in texture files of CDB ?

Hi,

As I understand it, you want to know if 3D Models in CDB can have textures with transparency (Alpha channel). Am I correct?

Best regards,

Salah

Hi,

As I understand it, you want to know if 3D Models in CDB can have textures with transparency (Alpha channel). Am I correct?

Best regards,

Salah

I know they have transparency, i just do not know whether to use alpha channel for transparency (for example; for glass) or to use the alpha channel for masking (for example; the leaves of a tree). In other words, i don't know how to interpret alpha channel.

Thanks.

Hi,

Chapter 6 specifies what the alpha channel of a texture represents depending on its intended use.

See section 6.13.5 for details. For instance, in a Night Map, the alpha channel is a mask.

Regards,

Salah

Thank you. It helps much.

Kind regards.

I'm not sure that was a full answer to the question...

Some rendering devices do need to know the difference between two different uses for an alpha channel (transparency or masking), where either one could be used in a base texture. The CDB spec doesn't differentiate between the two uses, and must leave it up to clients to determine which use of the alpha channel is intended (if needed).

BTW, this question should have been directed to the CDB Specification Forum as opposed to the CDB API Forum.