Whats the trick to get a Vehicle to sit on the ground in an environment?

I have a number of HDRI that I have tried including native ones. Vehicle is floating in mid air and does not look like it is part of the scene at all!

I would like to lower the entire ground plane in the window…
If I turn on ground plane, and choose asphalt, it still looks terrible.

Yet it seems to be possible

I want to do this inside Rhino. I dotn want to have to export and futz about just to get a quick render
Whats the trick?

The trick is in the shadow. Here a quick demo with the Mini from HoloMark by @Holo, using an environment from hdrihaven.com: urban_street_03

So in short:

ground-plane with shadows-only. Use skylighting to get useful lighting from the environment, and add lights where necessary to get the correct shadows. In the demo case pretty much just an rectangular light from the top, intensity bumped up a bit.

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Thanks for that. I am trying to do a 3/4 view from a low angle - just at the point where the ground plane is almost horizontal. At that angle, the vehicle is floating in the air above the street because the HDMI ground plane (street) is not aligned. It is below the Rhino Ground plane.
How do you apply a rectangular light from above? Need just a little more detail pls )

Are you rendering over a backplate, or are you using an HDRi environment?

To align your view and model you’ll have to do some fiddling with viewport manipulation (panning: shift+rmb drag, rotating: rmb drag, dollying: alt+rmb drag), and rotating your model to get the model, view and background to match up.

In the demo I added rectangular light in top view adding points counter-clockwise. But where you add your extra lights and how you orient them all depend on what background you’re using - the Rhino lights have to match orientation of the shadows in your background.

Just fiddle around until you’re happy.

Hdri’s are spherical in nature, and thus shot at a given level. Most Hdri’s you find online are shot at approx. 1 m., but there is no common standard. If you go below this level, things tend to float. Some renders (eg. Keyshot) have the option to flatten the ground level, so that the lower half of the Hdri is projected to a flat plane - I don’t know if something similar is available in Rhino (or in Cycles, maybe @nathanletwory?).
HTH, Jakob

Edit: If you go and download Hdri’s from eg. hdrihaven.com (they are free and great quality!) they come with a selection of backplates (at the bottom of the page of each file), and the result is much nicer. In order to have a decent quality directly from the Hdri, you need a massive resolution in the original picture

Not yet. I know @jeff has something like that in his secret treats bag for Rendered mode. For Cycles it has been requested upstream for the shadow catcher as well. But it may end up us implementing that for Cycles ourselves.

Please assume I am 4yo. Define backplate )
How do add a lightbox in Rhino step by step pls )
I have some good HDRi files. They all have the ground well below the ground plane in Rhino, probably 1m as you say.
I will look at downloading a backplate and experiement but again, a 4yo step by step would be great. Just assume I know nothing… cos i dont!
This is about the angel I need to create
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fcdn.motor1.com%2Fimages%2Fmgl%2FN0gnG%2Fs3%2Fchevy-corvette-at-dealership.jpg&f=1&nofb=1

In this simple example i rotate the hdr image similar to the backplate

-Use the information of the location of the hdr : long/lat and date

-setup location in Rhino and create a plane and align it to the perspective
-change time to get similar shadows in the backplate


I don’t know if it is possible to render the wallpaper directly or you need use transparent background and than use Photoshop for composition

HDRI

CAR Model

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Thank you for that:
“In this simple example i rotate the hdr image similar to the backplate”
Yes this is what I tried to do but, we are back to the original problem, all the HDRi files I have d/lhave the camera somewhat above the ground plane.

I am trying to render the vehicle as though the camera is very close to the ground plane. In all these Hdri files, the car is then obviously floating above the ground like a star wars speeder :frowning:

Note that in his screenshots you can see @seghierkhaled is using a backplate (just a simple image that is not an equirectangular texture like the environment HDRi textures) from the same page he got the HDRi. This backplate is set as the wallpaper for the viewport. The HDRi is used for reflection and skylighting environment.

I guess you’ll have to find an HDRi that is should from close to the ground with current Rhino.

Other render engine solutions may have features to help with this, users of these solutions will have to chime in.

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Can you share your hdr file? A compressed version

Aaaah Im starting to understand…

I have not made a rendering using a wallpaper. I need to try that.

Seghier, if you are asking me to share my HDRis, they very similar to the ones in this thread. Same camera angle. same kinds of backgrounds

The problem is they all have is that they were shot at 1-2m ABOVE the ground. Hence your model MUST be placed in the viewport to match - ie LOOKING DOWN on the vehicle as though you were standing.

My task is to render as though the CAMERA IS ON THE GROUND (or very close to it) I think I am now understanding that this requires a backplate/HDRI shot this way, which I have not found so far.

In Rhino you need to use a backplate.
There is another method to use half sphere unwrapoed in Blender and textured with the hdr image than use the projected hdr; but this work good with some hdris if the ground is flat and no geometris around the center.
And what you mean by shot 1-2m above the ground?
All camera’s used to shot hdris are above the ground.
Rhino used a ground by default to receive shadow ; you don’t need a plane with special material.
And show some steps or screenshots to better understand

I mean that the ground is 1-2m beneath the camera that made the HDRI image.
I need an HRDI where the camera was very close to the ground

You can check the hdr if it looks like this so no problem with the height.

And try use this half sphere (choose any hdr as texture), scale it and you can create mask texture to illuminate the top (sky), i never tried this in Rhino , @nathanletwory can confirm if this will work or not

half sphere.zip (3.3 MB)

Sefhier, I thiank you for your responses ) I think we are having a little bit of a disconnect in my desired goal.

This is the Camera angle I want to achieve… it is just above the ground.

I am rapidly realizing that this is not possible without using a ground plane. The problem with a ground plane is its not an image, it doesnt look like cement or tarmac or grass despite tweaking the materials available.

The ground plane also has a hard edge at the horizon that draws attention to the transition to the HDRi background.

The only HDRI that seems to work is a Studio that looks very similar to the ground plane, not the other way around.

This is all very dissapointing …

Hi @Proterio
You could try to use the Altitude setting under HDR Texture Settings (click the file name of your HDRi in the environment settings). This lets you lower/rise the the position of the HDRi “sphere” - it might be good enough for what you are after. Beware that the rendered viewport and Cycles seem to intepret the numbers opposite - in Rhino Renered View positive numbers move the HDRi up. In Cycles it’s the exact opposite - @nathanletwory could this be streamlined, so that positive/negative numbers mean the same?
Here’s the same view with the HDRi at Altitude left af 0 and Altitude set to -6 (in Cycles)


HTH, Jakob

Edit - Just for reference, here’s the same model and same HDRi (and approximate same angle) with the ground flattened (after 25 seconds of rendering in Keyshot).

Logged as RH-62381 Environment altitude incorrectly used in Raytraced.

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrggghhhh !!!

I was looking for something like that for hours… That menu is totally buried. What a terrible interface design.

Thank you leading me to that I will experiment

ADDED:
Unfortunately this didnt solve the issue of lowering the POV. It just permits rotation of the HDMi. It seems that the only solution is to create the HDMI with the camera on the ground or close to it.

@nathanletwory Something is totally wrong here! I never noticed this before, but it’s not that the altitude is interpreted the wrong way - the translation is the wrong type. In rendered view, the HDRi is translated up/down - in cycles it’s tilted left/right. By sheer chance my example above had the HDRi rotating the right amount, on the right axis (but negative numbers). I hope my small illustration makes sense :grimacing:


Rhino Altitude

Cycles Altitude

-Jakob

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