Backface Culling

reaganbrice

Good afternoon,

I don't think this is possible without using something like Unity or Unreal, but I will ask the question.

I'm using the Sketchup app and the AR aspect of it.

I'm trying to put something against a wall, that creates a chamber to look into. When looking from the sides you can obviously see the outside faces of the internal chamber.

Is there any way in Sketchup of hiding these faces. I don't want them to be tranparent, I need them to disappear.

I thought perhaps multiple sections could be used, a culling texture or a plugin.

Thanks in advance folks,

Reagan.

Dave R

Can you upload an example SKP file or at least an image of your model so we can see what you are trying to accomplish?

reaganbrice

Good morning!

Wow, didn't expect a repsonse that quick!

I've attached two files. The 1st is the model with the surrounding wall, the 2nd without.

When using this model for the AR aspect of the Sketchup App this wall is removed, but you can see all the 'workings' behind. This is what I want masked.

Hopefully you know of a workaround..

Thanks again,

Reagan.

Model with walls/floor.

Model without walls/floor.

Dave R

So you only want to see the stove and not the stone on the outside of the box surrounding it? If that's it, apply a color material to the back faces of the box and edit that color's opacity to be 0. When you look into the box from the front, you'll see the stone but from the back it will be transparent.

Click on the picture if it doesn't animate on its own.

reaganbrice

Thanks for that,

The issue there is that I want to make it look like the chamber is disappearing into the wall, so from the side I don't want to see anything internally.

I want the view as in image 1, but without the wall being there. The wall would need to be the mask that obscures anything being 'rendered'

I bascially want this to be a tool to show a customer what their fireplace would look like in situ.

Does that make sense?

Reagan.

Dave R

I'm still not following I guess. In part of your statement you are saying you don't want the wall visible but then you want it to obscure the stove and its surroundings. If it's masking the model of the stove and its enclosure as the viewer would see it in reality, then it looks like you've got it in your first screen shot.

reaganbrice

Sorry, perhaps not explaining it well.

I've managed (after great frustration) to get a screenshot of my issue.

Hopefully this gives some clarification.

Thank you for your effort so far!

Reagan.

Dave R

That clarifies what you are asking for. I have to think on it a bit.

TIG

Model the hearth, recess and fire, all placed in a large vertical wall face that stretches beyond the camera edges in all directions.
Do not model a floor face.
Paint the wall white.
Set the camera details to match the real photo image.
Adjust the shadows to match the real photo image.
Export the model's view as a PNG image.
Edit that PNG image [using Photshop, Gimp etc]
Set up a transparent layer for it.
Use the magic-wand to select and delete the wall face areas.
Now you have a cutout of the fire/recess with no wall, seemingly extending back into the wall.
Add this edited fire/recess image, on a layer over the top of the real photo image.
Adjust its size and location to show the fire/recess seemingly added to the 'real' photo.
Export the combo-image and the fire/recess will appear to be properly set into the existing wall...

reaganbrice

Thanks TIG,

That's what I've been doing up until now, but had hoped with Sketchup's App with AR function I could implement this 'live'.

I did have a play with Unity and Vuforia, but this requires a reference image.

I'm basically spending too much time providing bespoke drawings for customers and would like to give an impression of the fire in their home.

Thank you.

Reagan.

jiminy-billy-bob

How about modeling the wall, and projecting the photo to the wall face as a texture?

Step 10 here: https://help.sketchup.com/en/sketchup/matching-photo-model-or-model-photo#match-photo

reaganbrice

Would there be a way with multiple sections? I'm under the impression you can only have one section at a time. Can you have section cuts within Components?

reaganbrice

This may be down to my bad description, but to further complicate matters, I have different stoves, surrounds, hearths etc on different layers in order to show various options.

Projection may look weird unless you're standing in the right spot.

Good idea though.

Dave R

The hitch in the giddyup is that you are using an AR setup to allow the client to look at the modifcation from different angles. Is that correct? If so, these suggestions such as modeling the whole wall and projecting an image aren't all that workable.

I think the big thing right now, anyway, is that the AR stuff works well enough if the model is in the middle of the room where all of the real stuff is background. It's not very good for models that have to go through the background wall.

Dave R

@reaganbrice said:

Would there be a way with multiple sections? I'm under the impression you can only have one section at a time. Can you have section cuts within Components?

I'm not sure if it would help in this situation but you can place section cuts inside components so they only affect that component. And you can then have multiple section cuts displayed simultaneously.

reaganbrice

You're spot on with what you say.

Middle of the floor, not a problem. Free standing stoves are ideal.

The ideal solution would be a feature where I can apply a material to the wall around the stove (my mask) and for Sketchup to ignore everything behind it. I'm assuming this isn't something that could be achieved via a plugin?

It might be easier to go back to Unity and see what I can do there.

Thank you all for your suggestions.

Kindest regards,

Reagan.