coin in transparent gel

mibit

I made a simple composition: a coin (a cylinder with front image and bump map) inserted in a hemisphere of gel. The flat side of the hemisphere is leaning on a white floor. I see nothing in the rendering of the coin contained. I lit the scene with hdri light. I tried all the parameters, but I think I do something wrong. The gel - even if transparent - it is black and does not see anything of the coin that is black. If I remove the gel, then all is well. I tried to define the hemisphere with a different material: glass, but it happens the same. What is wrong? How do you advise me to do? between the rendering parameters I tried to put on and remove "light through transparency" and other.

shlomi laszlo

that is my try of it

evilproducer

I can see the half of the coin that's in the gel. Try lowering the refraction value to see if that helps.

Sockratease

Since you have checked all the settings, I guess "Light Through Transparency" is enabled.

Can't think of anything else that may cause that with a stock shader from Carrara's glass group. unless it has to do with the lighting??

Design Acrobat

I very seldom use the glass shaders as usually just make my own transparent objects in the shader room with transparency, refraction (ethyl alcohol), give a color (dark blue).

I would use caustics in the render room so you get that sparkle in the gel.

Lighting should be your last step after you do all the other stuff (except for the mindless tweaking). :)

I would use a three point lighting system even if you use HDRI. I would set the HDRI intensity in the assembly room about 20 percent or so, then play around with the intensities of the other lights (I recommend spot lights). One slightly red, one slightly yellow on each side of the camera pointed at the coin and gel. One spot behind the gel with the light color a bit darker blue than the gel color (or what other color the gel is).

I used both the HDRI and indirect lighting with the ambient occlusion checked so the coin features will show. (just used a bump, but a normal map for the coin would be must better)

It needs about another three or four houses of tweaking (cough) but this is a quickie on just one technique to light a gel.

I include the gel settings from the shader room for an example. But as I said before I stay away from the glass shaders and usually make my own. Just personal preference and the tinkering factor is addictive.

edit: Probably could use less intensity on the indirect lighting or the backfill light to get a richer blue or lower the intensity on the transparency. Dang, I need my eyes checked again, everything is blurry. heh

mibit

thanks! I wrote "gel" because I did not know how to define the material. I'm sorry that the parameters are not visible in the image that you have attached. How did you make the gel so well even in the form?

Design Acrobat

mibit said:

thanks! I wrote "gel" because I did not know how to define the material. I'm sorry that the parameters are not visible in the image that you have attached. How did you make the gel so well even in the form?

Not sure which person you are directing that to, but just in case I'll answer.

I made a bigger screen shot of the shader room parameters.

(right click - open link to see the original size)

For the sphere mesh, I just used a sphere, converted it to another modeler and in the modeling room I used soft selection to give a shape to it. I kept the whole sphere so the UV would be preserved (used box UV)