1
$\begingroup$

Example 1

ok so here is my problem. in this picture i want the White outside the Blue to be Transparent, and the White inside the Blue to to White.

this is as far as i get when just using the Transparent BSDF.

enter image description here

As you can see, both White areas are Transparent. is there any way that i can make the Outter Area the Only Transparent one??

EDIT 1:

after using cegaton's Advice i set up the nodes and such according to the 4th example,however the full sphere seems to be transparent now, regardless of color placed on the texture.enter image description here enter image description here

EDIT 2: i get the feeling this may just be too advanced for my level of skill in this current time period... perhaps somethin like this might be easier.enter image description here

In this example im using a stock lightning effect i found off Google. is there any way i can have this so that the black parts are see through, while keeping the rest of the image the same?

FINAL EDIT:

turns out im an idiot and just didnt realize the Alpha channel on the Texture got removed completely some how....quick trip to Gimp and 5 minutes later i got the results i wanted

Improve this question
$\endgroup$
9
  • $\begingroup$ You change the color input? What exactly are you trying to achieve. Also, if you are trying to make lightning, that is general done with volumetrics/compositing, see blender.stackexchange.com/a/28371/3127 $\endgroup$ – GiantCowFilms Jun 10 '18 at 2:30
  • $\begingroup$ The program im making a model for is relatively basic and cant handle much above simple models and textures. And the problem is im trying to use pure white in the model, but when i color anything that way its invisable since that is the color set as the transparency by default by the transparency BSDM. $\endgroup$ – brian dietterich Jun 10 '18 at 4:52
  • $\begingroup$ In that case you will probably want to use an image texture for your lightning. $\endgroup$ – GiantCowFilms Jun 10 '18 at 4:52
  • $\begingroup$ So is there no way to change the default transparency colour? $\endgroup$ – brian dietterich Jun 10 '18 at 4:54
  • $\begingroup$ What do you mean be default? You can click on the color input and set it to anything you like. $\endgroup$ – GiantCowFilms Jun 10 '18 at 4:54
1
$\begingroup$

Let's say you have an image with an alpha channel:

enter image description here

Which in turn, is nothing but a mask: an image with a black and white channel that determines the opacity of the RGB information. Black (0) is considered transparent, white (1) opaque.

enter image description here

If one were to use the image as color for the texture we get an opaque texture, because the alpha channel is not being used, just the RGB information.

enter image description here

Adding a transparent shader and using the alpha information to control the mix will make the black (0) pixels of the alpha channel be transparent and the white ones opaque (1).

enter image description here

If you don't want to use the color information of the image, but want to keep the mask to control the transparency, then just set the color of the shader to whatever color you want and use the alpha channel to determine the mix with a transparent shader.

enter image description here

If your image has no alpha channel you could still use the color information as mask:

In this case, since the mask information is in the blue channel, you can use any of the other two channels (red or green) to determine the mix between diffuse and transparent.

enter image description here

But your confusion is coming from thinking of transparency.

If what you want to do is mix colors (with no shader being transparent) then use the image as mask to mix colors.

enter image description here

Improve this answer
$\endgroup$
3
  • $\begingroup$ i tried all these different methods, every time i end up with a fully transparent sphere, im not sure what im doing wrong. $\endgroup$ – brian dietterich Jun 11 '18 at 11:05
  • $\begingroup$ It is hard to help you if you don't share what you have done. Please use the Edit link at the bottom of your question (i.stack.imgur.com/lXFuK.png) and add images that show what you did and the results you are getting $\endgroup$ – user1853 Jun 11 '18 at 12:59
  • $\begingroup$ See edited answer. $\endgroup$ – user1853 Jun 11 '18 at 22:22

Not the answer you're looking for? Browse other questions tagged or ask your own question.