Alpha Channel, Trees, Vray - HELP

jdcarling

Hey All,

I read this post and have figured out how to create the alpha channel in photoshop for a tree, but cannot find the location to insert the png properly in the material editor - diffuse - transparency. I clicked the lower case, then switched the left panel to TEXBITMAP but coudl not insert the alpha channel PNG anywhere... any tips.

thomthom

In the Transparency slot of the diffuse layer - add a TexBitmp:

kalu

Hi thomthom:

I have this dilema, I read the post all perfect. I try to mimic the results and I want to know what I am doing wrong. I attach the tree and the images for the render. Please let me know what I am doing wrong. I use Sketchup Pro 8 and Vray 1.48.89. Some of the leaves show as a rectangular green. I have no Idea why.

Here is the link to the 3D model of the tree:

https://rcpt.yousendit.com/1023169415/e1236da1e739047eed35fa1248da71be

Thank you!!!!

thomthom

That's because you didn't map the backside of the faces. You can even see that in SketchUp.

I'm guessing you imported this from another 3d format?
Because of that you lost the backside information. Many other 3d apps doesn't display anything on the backside of faces. You have to explicitly enable it.

To quickly transfer UV mapping from one side to another, use this plugin: http://forums.sketchucation.com/viewtopic.php?f=323&t=18992&p=155759#p155759

kalu

Thank you ThomThom, aweomse your plugin, I have that problem when Import 3DS trees...

This is the result:

thomthom

Nice

Where's that top tree from?

kalu

Is from ASGVIS, I need to use for a Tutorial that I work right now.

teris

i've tried it... but it didn't work out... i wonder what part i've missed...

teris

i've tried it using vray 1.48.xx,,, it works... just use the color texture as transparency option... but when i tried it using vray 6 with the explanation above,,, it still didn't work... i still wonder... help me out guys... thanks...

bac9-flcl

Isn't there a way to utilize normal transparency types supported in SketchUp? I'm talking about alpha channels in .png/.tga/etc textures.

I have a vast library of transparent materials, but all of them have transparency data inside, not as a separate file - and it is very inconvenient for me to make separate images with alpha, just to meet weird V-Ray standards. Is it possible (in V-Ray material editor) to assign alpha channel of e.g. RGBA .tga texture to be used as transparency map?

andybot

There is a check box in the material diffuse layer to "use color texture as transparency" for just such files.

ali64risk

@devran said:

rightclick on the alpha channel and save as a new picture... thats all

I tried but I could not...
please someone explain more?
(right clicking on alpha channel in Photoshop gave me 2 options: "duplicate channel" and "save channel"... where I can save alpha channel as png?)

nomeradona

ali.. what they were talking was the workflow for the old version. the new vray version, dont worry, just follow what andybot said.

ali64risk

@nomeradona said:

just follow what andybot said.

thank you
yes it is working