Texture Transparency
-
Hi,
I imported an image of a site plan as a texture. I wanted to place it on a polygonal face representing a site and place over a Google Earth snapshot. So far so good. But I wanted it to be translucent so one can compare the existing site for reference, scale etc. I projected the texture so I could adjust the site polygon after. I found that I could not make the image transparent in SU, so I edited it in GIMP.Is there another way? Is there a way to adjust transparency for an image texture within SU?
Peter
-
Haven't tried it but, if you edit the texture and move the transparency slider does that work?
-
It sure does.
-
Hmm.
Doesn't for me. This is a .png--perhaps that matters..
WAIT it can work for .png. Not sure why it didn't last night. I guess I was trying to adjust the texture of the group. I needed to work on the face itself. Since it is projected I have to make unique then sample and adjust the transparency, repaint. HOWEVER I can't recommend it as in this particular drawing it took faces away and created ghost images of my other geometry and generally made a mess. Something to study on the side. [OK I think I got it to work without the errors, Thanks!]
So, let's say I make a solid texture. Can an image texture receive a shadow?
Starting at the beginning: I import jpg or png as texture. place on a surface and it doesn't receive shadows. Is that right? Any way to cast shadows on this? In the entity window it says receive shadows for those faces.
-
Are shadows on at all? Any texture should receive shadows.
-
A PNG texture [with built-in-transparency] doesn't receive shadows.
A transparent material [irrespective of its texturing] doesn't receive shadows.
A face using a material with low opacity does not cast a shadow.
A PNG used as a texture in a material with low opacity should be translucent [see-through].
A PNG with an alpha-channel [i.e. a color set so that parts appear transparent] will be see-through for those areas even when the material using it as a texture is fully opaque - however, the whole face will cast a shadow, including seemingly see-through areas.
There should be no visual different between a PNG Image and and PNG Image that you've exploded so it's become a face with a new material applied that uses the PNG as a texture [except that the face's edges become visible and the face will cast a shadow - unlike an Image!]
If you want to convert an Image [that is a transparent PNG] into a 'cut-out' face that casts true shadows etc, and also receives shadows, then you need to use something like my ImageTrimmer tool on it...
However, some preprocessing of the PNG might be needed, to ensure proper fully transparent and fully solid areas of color are available for processing.
-
@tig said:
A PNG texture [with built-in-transparency] doesn't receive shadows.
But TIG, I get png textures to receive shadows!
-
I just did a test on that, and I too get shadows on PNGs
-
IF you use a non-transparent PNG as a material-texture then it casts shadows - just like a JPG would.
BUT IF that PNG has an alpha-channel [transparency] then it doesn't cast a shadow ever - irrespective of whether or not the material using it is fully opaque ! -
Ah TIG, originally you said the with or withouttransparency and that confused me (I have seen the moderator logs about you editing
) -
Thanks Tig, always willing to learn something new.
-
@gaieus said:
Ah TIG, originally you said the with or withouttransparency and that confused me (I have seen the moderator logs about you editing
)
You are right - I meant the materials transparency - it was ambiguous I edited it for clarity...
-
-
I think that's it. Give that man a cigar!
I added Alpha channel at the beginning to be able to eliminate the white around the borders of the site. The rest of it was solid opaque. I'll check by other methods
Thanks!
Peter
-
Because of the issue I added an extra step near the end of my ImageTrimmer tool.
The PNG Image initially needs transparency to work out what;s to be cut off the shape.
But then you have a component face with a material using the PNG as a texture that won't receive shadows
SO you are then asked if you want to 'flatten' to texture image so it works [like a JPG], rather than the transparent PNG ! Answering 'yes' fixes it [it's automatically made anyway and is discarded if you decide not to use it!]
Advertisement