Motion Study Rendering flicker on Emissive apperance

[Anonymous]

The result of motion study render on the following file is flickering.

The appearances are set as follows ("A.B" denotes component B inside component A)

• Top
  •  .Coverglass - Glass (Clear)
  • .Screen - Display - LCD (emissive component)
  • .TopCover - Aluminum - Anodized Rough (Grey)
• Bottom
  • .Keys - Plastic - Textured - Regular
  • .BottomCase - Aluminum - Anodized Rough (Grey)

Please see video in the attachment.

[karina.harper]

Hi @Anonymous 

I believe this is due to two appearances being applied to the emissive body. I removed one and re-applied and it looks like it works. Would you mind trying that out and seeing if it works for you?

Here's a screencast on how to do it.

[Anonymous]

Hello the solution is not accepted as the item still flickers. I require that the LCD appearance be applied to the Screen layer and not COverglass. It will require drag and drop directly to the Screen page since it is under the coverglass.

I am unable to remove another appearance since the physical material is applied to the item. at the minimum, there is a default material of steel which will automatically apply appearance to the item.

Requirements summarized

Top.Coverglass be Glass - Clear

Top.Screen be LCD

The Screencast shows Top.Coverglass appearance set to LCD which is not intended.

[Anonymous · Accepted solution]

Found the issue. When the Top.Screen is touching Top.Coverglass, the rendering engine may get confused which object to render on that particular surface. I extrude cut the Top.Screen away from Top.Coverglass a little essentially creating an air gap. That fixes my issue. However since I was trying to simulate a fused display which is glued on, there would always be something touching the screen, either the glass or clear glue.

Either-way, please let me know if it was an unexpected behavior or if it is intended per design.

Thanks.

[karina.harper]

Hi @Anonymous 

I would say this is intended behavior as having two materials applied to the same face would never happen in reality. You're right that there would be a glue layer, so it makes sense that there would be a small amount of distance between the two materials. The rendering engine would not know which one is truly on top, as in Fusion they exist in the exact same plane of space.

[Anonymous]

So the emissive layer is only the face?

Given the whole body is emissive and the glass is considered in the same plane in space as the body. The body should still glow, even if the face of the emissive body is replaced by face of a non-emissive body.

[karina.harper]

@Anonymous 

The issue is that the face is both emissive and glass at the same time. When you apply an appearance to a body, it is applied to all the faces on the body. Then you're adding another one onto the same face. Maybe if you apply the emissive appearance to all the faces except the glass one, it might work. Does that make sense?

If that doesn't work, it is probably because the emissive material doesn't exactly apply to the inside of the body. You would have to unstitch the faces and then apply the material to the inside of the faces that are facing towards the screen.

[Anonymous]

The two appearances on two faces was resolved long ago for me but it still wasn't the only issue. Once the all faces of each body only have one appearance, the behavior continued.

I resolved this by untouching the bodies. The said two bodies only had one appearance applied to them but had one of their faces on the same spot as one another. Once I added an air gap I told you about earlier the issue is resolved.

My question is, even with two faces touching, the glass BODY is clearly on top and the emissive BODY is clearly behind. Shouldn't the face touching face not be an issue since the behind/front is defined clearly by the fact that the front body is not emissive and clear and will never in real life block any light even if the faces are touching.

Please note that your screencast did not resolve the issue the way I wanted since you simply applied appearance on the top surface body. I wanted the emissive body to be completely inside between the glass cover and a back cover.

[karina.harper]

@Anonymous 

I see. That is a good question, I think in general it is still an issue as in "real life" they could never exist in the same place. There would be at a minimum a layer of molecules that would separate them. Fusion on the other hand doesn't respect the laws of physics, so we're getting something of a Schrodinger's cat situation. Since the face (or the space the face occupies) is at once a light source and glass, the renderer is allowing them both to exist at the same time and therefore flickers between the two.

[Anonymous]

In what case would a flicker be desired when the faces are touching?

I still think fusion should just pick one and not flicker at all. I guess this is a special case for motion study rendering. If this only effects emissive + clear items then it would be nice if you could throw in some warning triangles before a user go use their credits.

Thanks!

[Anonymous]

Would also be awesome to do a motion study render preview locally. My PC can handle it. At least 200px by 200px so at least I can tell there would be flickering.

[Anonymous]

I think it should be easy to add a special case unless fusion is not developing the renderer internally.

Just do for each frame

if(numberOfFacesTouching == 2) {

    if(body1.averageMassLocation.isInFront(body2.averageMassLocation, cameraLocation)) {

        body2.frontFace(cameraLocation).extrudeBack(smallestDistanceAllowed)

    } else  if(body2.averageMassLocation.isInFront(body1.averageMassLocation, cameraLocation)) {

        body1.frontFace(cameraLocation).extrudeBack(smallestDistanceAllowed)

    } else {

        //do nothing. body is overlapping.

    }

}

This should allow the renderer to not get confused any more. Although this probably won't work. Just an idea to hopefully be derived from.