Atmosphere

Is this possible with C3D?

Hello all!

I'm fairly new to Cheetah3D and 3D modeling in general, but I must say Cheetah3D is very simple to play around with and learn from.

I was playing around with the "Hello world" example this morning and was easily able to recreate the tutorial. I then got to thinking about making an atmosphere of clouds which would encompass the spinning globe. So, I created a cloud texture in Photoshop leaving some transparent and semi-transparent areas in the texture. I saved it as a PNG file.

In C3D I created a new ball object and made it's diameter larger than the globe so the globe was contained entirely within the new ball. I then created a new material and loaded the clouds.png texture and applied the new texture to the larger ball object.

When I render the scene the clouds appear perfectly over the globe except along the outter edge where the transparent areas show through to the gray colored back side (inside?) of the geometry of the larger ball object. Is there any way to correct this? Perhaps a double-sided texture/polygon?

Thanks for any guidance and help.
Don

I think that the problem is that your material is not black in the diffuse channel where it's transparent, and it's not 100% transparent (I'm guessing) so the back side of the material is reflecting a little diffuse light.

The solution is either to darken the diffuse map over the transparent areas OR to make the transparent areas more transparent (or both).

Thanks for the reply, podperson.

As I stated in my opening message, I am rather new to all this 3D stuff. I don't know what a diffuse map is or how I would make it darker. I've seen the Ambient and Diffuse settings in the material editor, but neither of those make a difference.

I thought a simple PNG with transparency was all I needed. I guess it's a little more complicated.

Don

A simple PNG with transparency should work fine -- the point is that the transparent areas need to be completely (100%) transparent OR their diffuse color will show through.

Ahh I see. Thanks for clearing that up.