topic Re: Materials don't display or behave correctly in Fusion Support Forum

Materials don't display or behave correctly

terry_fusion — Fri, 20 Oct 2023 15:34:34 GMT

This has bugged me since day one but I've had other larger Fusion fish to fry, what is the reasoning behind why Fusion doesn't display material and their properties as they are defined.

I can set a body to be clear plastic from a properties and appearance standpoint but it doesn't render/display those properties as it should.

Even if I change the body opacity all the way down, the decal/graphic doesn't show thru

As an example in my work, daily I design and lay out graphics in our shop to be printed on clear acrylic (second surface) on the backside showing outward to thru to the front.

Fusion will not give me an accurate display of a decal showing thru a clear/translucent material, basically useless, I can't even show a client how their graphic will look in the overall design because I can't display it.

OK, so after a bit more investigation on my part, I've discovered that the only way a decal/graphic appears thru an object is in the decal dialog, which has an opacity slider (my oversight).

By selecting this you can change the amount of opacity the decal has rather than the body its placed on? Seems counter intuitive?

Also each environment changes the way the decal/graphic is shown, darker or lighter to varying degrees, I feel the environment should not alter the real world appearance or physicality of a part.

Re: Materials don't display or behave correctly

TrippyLighting — Fri, 20 Oct 2023 15:34:52 GMT

The purpose of the opacity setting and generally the 3D design viewport of Fusion 360 is NOT to provide an accurate view of geometry with applied materials. That might be technically passible with the simple acrylic pane in your video, but I work in designs often with thousands of components and it would be a huge performance sink!

The 3D viewport is optimized for speed, not for accurate display of physical materials. That is particularly the case for dielectric materials that have absorptive and refractive properties!

However, I just tested this and on my machine, When I rotate the acrylic pane, I can see the decal from the back.

Also, the environments use a HDRI to illuminate the geometry visible in the viewport. Lighting absolutely changes the appearance of objects in the physical world!

A better preview of dielectric materials can be seen in the real-time render preview. For best results you should create a render. For absolutely photorealistic rendering of dielectric materials you need to use a spectral render engine outside of Fusion 360.

This is a view onto the backside of the Acrylic Pane in the design viewport :

Same design in the Render Preview. There you can change the HDRI that is used to illuminate the scene:

This is a still render:

Re: Materials don't display or behave correctly

terry_fusion — Fri, 20 Oct 2023 15:39:40 GMT

Forgot about the HDRI in the view port, that does change the lighting situation, I was thinking it was a static not a dynamically lit view port.