Hello

I am doing some traditional modelling in houdini and have set up front and side image planes with 2 Grids.

I have set up a material and have a custom parameter so I can control the OpenGL alpha with a slider. The slider only allows for either completly transparent or completly opaque.

Is there a way to fade out the alpha (of the geometry) in the viewport to see the image planes in the background? Also I would like to be able to still see the wireframe when becomming transparent.

Hopefully that doesn't sound too confusing.

is the custom parameter an int or a float?

I tried both but it would only work with a float which I thought was a bit odd.

Do you have transparency enabled in the viewport display options? (Effects tab)

Yeah transparency as enabled (I upped it to High quality with no effect.) I must be doing something wrong with the shader.

Adjusting the OGL Alpha slider to anything less than 1 makes is completely transparent and doesn't fade off like I would expect it. Also makes the wireframe completely invisible too.

I think I might be barking up the wrong tree

Ok problem solved!

Turns out the shader wasn't the problem.

In the display options to the right in the viewport I had the high quality lighting button selected, simply changing this to “normal lighting” or “headlight” solves the problem.

I get a fading opacity.
I still have the wireframe visible, and
I still have the image planes in the background visible.