Alpha channel problem

sky14 · 29-Feb-2012 09:29:59

Hi,
I have a small problem with the alpha channel.
So, I made the texture with the alpha channel(I wanna get transparency), but when I'm importing the model with this texture to the editor, there, where should be transparency is a black colour instead of it.
Is there some solution?

Thanks in advance

arkeon · 29-Feb-2012 09:35:20

Hello,

You have to create a material that manage alpha too.
If you use 3ds max to create your objects, just set a transparency on the material (with Easy Ogre Exporter).

if you want to modify manually the material script see : http://www.ogre3d.org/docs/manual/manual_14.html

Nodrev · 29-Feb-2012 09:45:49

For transparent objects, the related material parameters are "depth_check"/"depth_write": http://www.ogre3d.org/docs/manual/manual_16.html#SEC49

sky14 · 29-Feb-2012 09:52:51

Thanks for helpful replies.

Last edited by sky14 (29-Feb-2012 11:39:34)

sky14 · 29-Feb-2012 16:11:09

Ok, I managed to make transparency but still I want to get a bit different effect.
I made a two images which will show what I mean.

First image showing effect which I have currently:

Second image showing effect which I would to get.

My question is, how to get such effect like on the second image?
BTW. I use the Fragmotion to exporting models and all changes in the material I must write manualy.

arkeon · 29-Feb-2012 16:19:23

try this in your pass :

                        ambient 0.447059 0.447059 0.447059 1
			diffuse 0.588 0.588 0.588 1
			specular 0.203922 0.203922 0.203922 1 10
			scene_blend src_alpha one_minus_dest_alpha
			alpha_rejection greater_equal 128
			cull_hardware none
			cull_software none

			texture_unit leavesTex
			{
				texture texture.png
				filtering linear linear linear
			}

Nodrev · 29-Feb-2012 16:20:51

Ok, for a tree, use "alpha_rejection" on the pass (http://www.ogre3d.org/docs/manual/manual_16.html#SEC54). It takes a parameter between 0 and 128, which will be used for checking if the value in the alpha channel is upper or equal to it. If so it will show the colour on the rgb channels.
You can also use "alpha_to_coverage on" for better quality (smoothed edges between transparent/visible).
<edit>gasp arkeon got me again, bip bip</edit>

Last edited by Nodrev (29-Feb-2012 16:21:27)

sky14 · 29-Feb-2012 16:59:17

Ok, I added alpha_rejection command to the material and now it works! Thanks for help!

hebdemnobad · 1-Mar-2012 00:44:53

fwiw there are quite a few threads on the ogre3d.org forums about alpha materials....if you look for my username and 'alpha' there you should find some code

Scolring - Forum

#1 29-Feb-2012 09:29:59

Alpha channel problem

#2 29-Feb-2012 09:35:20

Re: Alpha channel problem

#3 29-Feb-2012 09:45:49

Re: Alpha channel problem

#4 29-Feb-2012 09:52:51

Re: Alpha channel problem

#5 29-Feb-2012 16:11:09

Re: Alpha channel problem

#6 29-Feb-2012 16:19:23

Re: Alpha channel problem

#7 29-Feb-2012 16:20:51

Re: Alpha channel problem

#8 29-Feb-2012 16:59:17

Re: Alpha channel problem

#9 1-Mar-2012 00:44:53

Re: Alpha channel problem

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