Accumulation buffer/subtractive blending?

cowsarenotevil · Post by **cowsarenotevil** » Wed Mar 29, 2006 4:27 am

I'm just curious as to whether Irrlicht supports using the accumulation buffer or subtractive blending on objects. Either one will work for me, but if both are available I'd like to know. If someone could point me to something in the API documentation, that would be great.

Thanks.

EDIT: Oh, and how about (ZERO, ONE_MINUS_SRC_COLOR) for blending? This isn't quite like true subtractive blending, but for some uses it's an acceptable approximation.

hybrid · Post by **hybrid** » Wed Mar 29, 2006 9:35 am

You should check the material definitions for these things. But if it's not supported right now it should be easy to add a new material that fits your needs.

cowsarenotevil · Post by **cowsarenotevil** » Wed Mar 29, 2006 10:59 am

hybrid wrote:You should check the material definitions for these things. But if it's not supported right now it should be easy to add a new material that fits your needs.

Hmm. I'm still quite new to irrlicht, so I'm not really sure where to look. I've looked _here_, and I didn't see anything particularly promising. Is this even what I should be looking through? EMT_DETAIL_MAP looks like it might be able to do what I want, but I couldn't really understand the description. I'll probably need to do a bit of experimenting. I don't think I've actually even tried alpha blending with Irrlicht.

I do know that using OpenGL, there's no way to impliment real subtractive blending aside from using extensions.

EDIT: I wish links showed up as a different color automatically...

hybrid · Post by **hybrid** » Wed Mar 29, 2006 1:10 pm

I guess it's the simplest to search the source code for your OpenGL or DirectX statements. If they're not there, no material will do exactly what you want. If you have some particular high-level behaviour in mind, you might succeed with browsing through the material descriptions. But his might not really match your specific requirements.