Looking through Glass

[tlehnhaeuser]

For the life of me I cannot seem to get good glass renderings.

 

My objective is to be able to look at a graphic (decal) that is behind a glass panel.

 

I can never get this to work for some reason. Maybe can steer me into the right settings?

 

V11 PU1

 

My current Settings:

 

- 100% transparency

- 0 reflection

0 refraction

Rendering Both Sides

Triangular Mesh

Using 3D background with color illumination

 

Thanks

Tom

 

 

 

Edited February 26, 2009 by tlehnhaeuser

[Cary OConnor]

Did you try the common glass from the Glass catalog?

 

You need refraction and Fresnel to make glass look like glass and something to reflect/refract (I used the mall environment from the Partner CD from Dosch).

 

 

[Guest Jan Lyttbacka]

Nice Cary

 

 

R

 

Jan

[Cary OConnor]

You can even make it more interesting by setting the Index of Refraction high (3.0 for example).

 

[tlehnhaeuser]

Did you try the common glass from the Glass catalog?

 

You need refraction and Fresnel to make glass look like glass and something to reflect/refract (I used the mall environment from the Partner CD from Dosch).

23742[/snapback]

 

Yes I have tried all that.

Do you have a gap between the decal and the glass? Or is the decal directly "sitting" on the back of glass.

 

Is the decal on the glass part or separate part?

 

Thanks

Tom

 

[tlehnhaeuser]

Cary can you send file.

I cant get mine to work

tom

[cborer]

Tom

I am not a render specialist but philosophically I think glass is not 100% tranparent

I would try 99%

Best

Carlo

[tlehnhaeuser]

Tom

I am not a render specialist but  philosophically I think glass is not 100% tranparent

I would try 99%

Best

Carlo

23752[/snapback]

 

 

Thanks Carlo-ocrates

I think your right since IronCAD's glass is set to 99%.

However is still doesn;t work.

 

I finally got it to work if I set the front and back faces to 100% trans.

But this is not accurate since you see the "sharp" edge transition.

 

cheers

Tom

 

 

[Bryan Cargill]

You are missing everything behind the transparent surface. This may mean it is a "ray depth" problem.

 

The ray depth tells the renderer how many things a ray is allowed to hit before it is considered "done". Hits can be propogated from reflections or refractions. This limit is needed to speed things up and also to prevent an infinite loop in the case of two parallel mirrors (mirror A can see mirror B looking back at mirror A etc...)

 

If the ray depth is too low-- the ray will act as if it is done (has hit the background) prematurely. This results in seeing the background where some other geometry would be expected. The default of 4 is ok for very simple scenes, but if there are multiple layers of transparency-- you must raise the value manually.

 

For example-- looking at a cylinder through a single pane window rendered as 2 sided-- a value of 3 is ok (enter glass + exit glass + hit the cyl). Looking through a double pane window, a value of 5 is needed. Looking through a stack of 2 double pane windows-- a value of 9 is needed. etc...

 

You don't need to understand exactly what value is required. You just need to know to raise the ray depth value if you see this issue. Try raising the ray depth value to something like 10-- it is located on the Image tab of the Advanced Rendering Properties dialog.

 

Here is the single pane example:

 

Ray Depth = 2

 

Ray Depth = 4

 

 

 

And, here is the double pane example:

 

Ray Depth = 4

 

Ray Depth = 6

 

 

 

 

 

 

[tlehnhaeuser]

AHA!!!

Thats makes sense now! Let me play and see how it works.

thanks for detailed insight, this is the sort of explanation I need for it to click in my head.

thanks Bryan, your the man.

Tom

 

[Guest EricFoy]

One very important point:

 

Always double check to make sure you have "Render`both sides of surfaces" checked on the Part Properties | Rendering dialog. This one gets me every time.