Begginer quick question... transparency

[Papoames]

Begginer quick question... transparency

Does Cheetah 3D support the transparency of a .png or .psd file at all when applying a texture to an object? The only way I have seen in the forums is multiplying the texture -- but I don't want that -- I want to overlay a texture on top of another texture with the alpha channel "knocking out" the texture below. Multiplying just makes it too dark and flat. I need to clarify this before moving on. Thanks in advance. BTW, I love everything I'm learning.

-Papoames

 

[Swizl]

Does Cheetah 3D support the transparency of a .png or .psd file at all when applying a texture to an object? The only way I have seen in the forums is multiplying the texture -- but I don't want that -- I want to overlay a texture on top of another texture with the alpha channel "knocking out" the texture below. Multiplying just makes it too dark and flat. I need to clarify this before moving on. Thanks in advance. BTW, I love everything I'm learning.

-Papoames

Hi Papoames and welcome to the forums!

Yes, you can activate the transparency in a png material. You have to select the "use alpha channel" box in the material properties in the transparency section to activate it. Make sure your image is RGB.

 

[Papoames]

Thank you!

 

[frank beckmann]

In addition you´ll need to set the Index of refraction to 1,0 and when using an explicit light source set Shadow Type: to Raytrace+trans for letting the light rays pass through the mapped geometry.

Cheers
Frank

 

[misoversaturated]

I want to overlay a texture on top of another texture with the alpha channel "knocking out" the texture below.

From what I get about the material system in cheetah you can't mix materials, so there is never an "underlying" material on which another could be overlaid.

You have to mix the textures within the same material via nodes.
There is a background property of the image node, but I can't get that working.
But you can access the alpha channel of an image with a vec2float node and thus drive a mix node.

In the example below the image node has the texture to be overlaid and color 0 of the mix node provides the background color (here set to white).

When your background material has different properties regarding reflection, bump or else, you need additional mix nodes for those properties in the material node just like you might have different reflection or bump maps.

Please see the difference of the effect of the alpha channel checkbox (drives transparency) versus the mix node setup (image on white background) in the pics below:

 

[frank beckmann]

From what I get about the material system in cheetah you can't mix materials, so there is never an "underlying" material on which another could be overlaid.

You can overlay image textures with the composite node.
And I don´t get why you´ll need any nodes just for an alpha channel image texture; check "Use alpha channel" - set I.o.R. to 1,0 at the material node and you´re done:

Cheers
Frank

 

[misoversaturated]

You can overlay image textures with the composite node.

Thanks for that tip, that's indeed better than my node work!

And I don´t get why you´ll need any nodes...

Because the thread opener didn't ask for transparency with respect to the background behind the object but for transparency to an underlying texture on the same object, as far as i understand the question, but I may be wrong.

 

[frank beckmann]

Because the thread opener didn't ask for transparency with respect to the background behind the object but for transparency to an underlying material on the same object, as far as i understand the question, but I may be wrong.

I think the same composite node will work here as well as you might already figured out: http://www.cheetah3d.com/forum/showpost.php?p=84607&postcount=2

Cheers
Frank

 

[ZooHead]

Just having fun testing.

I put a brick texture on the bump channel and two
spot lights with tree silhouette images for drama.

​

 

[uncle808us]

I had to try this too very cool Frank.. never used composite node wow, I'm slowly grasping (though be it loosely ) the node editor I think the one thing that holds me back is no previews in the main views only when rendered.

 

[Papoames]

Thanks to all.

First, let me just say how outstanding it is to have someone like Frank answer your questions. Cheetah 3D (especially coming from Cinema 4D) is way different when it comes to materials. I hope (one day) to become 1/10th the Cheetah 3D artist that Frank is. Kudos. That said, I lament the availability of a singular clearing house of VIDEO tutorials (with VOICE) to assist in learning KEY concepts. But, such is life. Cheetah 3D is certainly keeping my mind occupied and exercised, in a good way. Again, thanks to all.

-Papoames

 

[Joel Ruiz]

Okay I can't figure out this. I have saved this image in PNG format with transparency, and also in PSD format with an alpha channel. I have tried both with no success. I want the cat to show on top of the underlying material.. how is this done?

Here's the png image:

 

[Swizl]

Hi Joel,

Some of the nodes don’t show in the 3d viewport (mix and composite being two of them). You have to render to see them.

Hope that helps. If not I’ll take a look tomorrow. I’m on my phone and I’m about to head to bed.

 

[Joel Ruiz]

But as you can see in the render.. it's not working for me.

 

[Swizl]

But as you can see in the render.. it's not working for me.

Sorry about that! It was late last night and I must have been tired. Is it a problem to attach the file? It may make it easier to track down what's going on.

 

[Joel Ruiz]

I'm pulling my hairs here lol.. why am I getting distortion on the projected texture?

Why do I get a blue preview instead of the texture preview when activating the UV Mapper?

 

[Shift Studio]

I'm pulling my hairs here lol.. why am I getting distortion on the projected texture?

Why do I get a blue preview instead of the texture preview when activating the UV Mapper?

before getting in too deep - are you using a sub-div modifier on your mug? If yes, you're going to need to 'make editable' ... that is burn in the Subdivision modifier before UVMapping. That'll take care of some distortion. You could use the UVMapper tool next.... or to do it with more precision, you'll need to use the UV Unwrap tool to get rid of remaining distortion (not use UVMapper tool). Are you familiar with making seams and UV unwrapping?

--shift studio.

 

[Swizl]

I agree with Shift.

I think the taper on the mug may also be what's causing the distortion. Sometimes I add a 1x1 square temporarily on my texture when I'm UV mapping so I can get an idea about how much the texture is distorting. After I have my UV scaling and position set, then I just replace the image back to the original one without a square on it. Working in the UV editor is more exacting, but does take more effort.

In regards to your earlier problem, it can be tricky mixing procedural shaders with bitmap textures that have alpha channels. It can be done, but it takes more in depth node connections to do it. I think there is a coke bottle or beer bottle thread somewhere that has some of the ins and outs on doing that. Did you original mug have a diffuse texture or was it a procedural ceramic one?

 

[Joel Ruiz]

before getting in too deep - are you using a sub-div modifier on your mug? If yes, you're going to need to 'make editable' ... that is burn in the Subdivision modifier. That'll take care of some distortion. You could use UVMapper next.... or to do it properly, you'll need to use UV unwrap to get rid of remaining distortion (not use UVMapper tool). Are you familiar with making seams and UV unwrapping?

--shift studio.

Thank you Shift.. I suspected it had to do with UV unwrapping.. and no, I'm not familiar at all with it, I wish there was a detailed tutorial for this in Cheetah, all I found was this by Frank: Link Video, and that's what I used to apply the texture using cylindrical mapping. Yes, I have a subdiv modifier, I'll make it editable and see if that helps some, but I'd like to be able to have zero distortion on the texture.

Can you point me in the right direction? Thanks a lot!

I agree with Shift.

I think the taper on the mug may also be what's causing the distortion. Sometimes I add a 1x1 square temporarily on my texture when I'm UV mapping so I can get an idea about how much the texture is distorting. After I have my UV scaling and position set, then I just replace the image back to the original one without a square on it. Working in the UV editor is more exacting, but does take more effort.

In regards to your earlier problem, it can be tricky mixing procedural shaders with bitmap textures that have alpha channels. It can be done, but it takes more in depth node connections to do it. I think there is a coke bottle or beer bottle thread somewhere that has some of the ins and outs on doing that. Did you original mug have a diffuse texture or was it a procedural ceramic one?

I momentarily saw a post by Frank right after my original message where he created a mug and applied the cat texture.. alas the post dissapeared lol.. I did the same as I remembered he did, but I was not successful. It seemed fairly easy with the compose node.

I come from an app called Electric Image, it has all kind of projections, like cylindrical, and no matter what the geometry looks like, it simply projects the image uniformly. I was hoping for something like this in Cheetah but I guess there's only UV mapping so I'll have to learn to unwrap hahah.. damn I'm too lazy..

 

[Swizl]

Here's the thread about mixing an alpha texture with a procedural material (in this case glass, but I suppose it will work for any of them).
https://www.cheetah3d.com/forum/showthread.php?t=9795&highlight=glass+label

I know there are some more UV mapping tutorials somewhere. Let me see if I can scrounge them up.

Here's an older one by podperson on his website. http://loewald.com/c3dbook/Older-Tutorials/UV-Mapping-(video)/

I'll see if I can find some other good ones. UV Mapping takes a little trial and error to start learning. So sometimes you just have to poke around a little bit to figure it out.