Vlado, i beg you!

[Tony_Morev]

PLEASE! PLEASE! PLEASE!

make alpha mapped TARGA's work with v-ray material

it's just ridiculous how such a basic function doesn't work in such an advanced rendering engine

thank you!

[egz]

Exactly what is the problem with alpha mapped TGA files? As texture bitmaps? As rendered output? Both these work fine here.

[Tony_Morev]

huh ...

the problem is in using one single instanced TGA file both as a diffuse and opacity map with v-ray material

with standard material it renders very slow if it's multi-layered
a good example of it is speedtree

refraction slot in v-ray material doesn't react to alpha channel the way max opacity does
somehow alpha either gets inverted or it comes through full color ...
i don't know ...

Vlado knows about that problem

in case you know a good solution, would you be so kind to post a sample file

[egz]

Ok, so the problem is actually not related to Targa specifically, but rather opacity mapping vs refraction mapping? And it would produce the same result with a TIFF with an alpha probably?

What are you trying to do? And could you post a picture or a scene with one material that does what you expect (in scanline)?

[dbuchhofer]

The problem has nothing to do with targe files.. it is the lack of an alpha channel for any refractively transparent VrayMtl.

Ex: Glass material, Vraymtl, Refraction white, ior 1.6. Render, Check the Alpha channel (Either in the vfb by clicking the display alpha channel button, or by saving the file as an alpha enabled filetype.. Commonly TGA..

Alpha channels for Refractively clear objects show as being SOLID...

A bit of an annoying in compositing in general. Though good for compositing reflections via overlay modes. Interesting to keep for special cases, but DEFINATELY needs to not be the default or only way ot having alpha in the vraymtl..

Workaround that works not so well: Add a VraymtlWrapper around the Vraymtl and set the Affect Alpha in there. Be careful though, as the Vraywrapper and the Object mode matte properties are not compatible, and the wrapper takes precedence.

[egz]

Hi Dave,

I think Tony is talking about something else. It seems he has some problems with opacity mapping using instanced targas, either that or I am thoroughly confused.

BTW: Refraction alpha is on Vlado's To-Do list, and should be in one of the coming builds. There is also another workaround that involves the blend material: http://vray.info/entry.asp?entryID=91

[Da_elf]

ive never thought a refractive alpha makes sence. if refraction warps whats behind it. and you have an alpha on it then when you comp the image with a background...the background shown through that alpha wont be warped

[egz]

That's right elf, but at least it will be transparent, not solid. You can always warp the BG in post using a normal pass, and then comp it. With a solid alpha from refractive areas, this becomes rather hard.

I think Vlado is on the right track now, the fresnel affect shadows option of 1.09.03g produces great transparent shadows, and I suppose the same code (or the same principle) could be used for the alpha channel of the object as well.

[J_Bug]

Are you maybe talking about how a targa resets its alpha parameters at random times?

[Tony_Morev]

wow it sound's like there might be more problems with it than i thought

what i'm trying t accomplish is an easy setup for things like "billboard" trees
it would also work great for speedtree

in default max material drop 32bit targa with B&W alpha on diffuse
set mono channel output to ALPHA
and instance the same map to opacity channel
voila! if you have all colors black and no hotspot
you will have a perfect leaf or tree or whatever image you used

now try to do it with v-ray material
since a bunch of those trees done with standard materials could kill your rendering times

i'll try what you guys suggested
although i think already tried it before

right now the easiest way to fix the problem is to un-instance the maps
and on refraction map check "alpha as gray" and invert it
weird isn't it?

and it seems like not that big of a deal if you have just a few trees to deal with
but if i'm working on a big site all those un-instanced maps could create a big mess

by the way i agree that alpha mapping on refraction makes no sense ...
probably like any other kind of mapping on refraction
i'm all up for having an nice OPACITY slot in v-ray material =)

[plastic_]

>>i'm all up for having an nice OPACITY slot in v-ray material =)

i'm up for useable rendertimes with the standard material. proprietary materials suck.
i can live with them for glass, but i can't afford using plugin materials for everything. what if i want to work on the scene on a computer without vray? or if i switch renderers?

[egz]

No you don't want an opacity map since this is already there (opacity is part of refraction), you want a clip map.

[Da_elf]

there ya go. egz just hit the nail on its head

[zerofractal]

I want a clip map

[GoncaloP]

Me too