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So, longtime lurker here. I have a bit of a problem.

I've been generating AI-based spacecraft for a while now, and I've wanted to try my hand modeling one of them — this one, to be specific:

enter image description here

Obviously, AI images have some distortion and inconsistencies, but I'll tackle those as they come up. My current problem is that I can't figure out how to compensate for the angle in the photo. I really don't want to just freehand it, but match it to the reference as closely as possible.

I've considered fSpy, but there aren't any parallel lines I can take advantage of — the thing is in space after all. I need a way to get a top-view, or at least estimate one. From there I cn start the guesswork.

Any and all suggestions would be fantastic.

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    $\begingroup$ I don't think this is a question about working in Blender. Getting top or side views from existing or fictive vehicles to use them as reference for modeling is usually to be done outside of a 3D software, maybe with some photo-editing software etc. to then have something you can import as reference. $\endgroup$ May 21, 2023 at 13:03
  • $\begingroup$ @GordonBrinkmann Would you happen to have any suggestions for doing that? $\endgroup$ May 21, 2023 at 20:50
  • $\begingroup$ For getting an orthogonal axis aligned top view from the AI image in some photo editing software? No. For trying to derive it from the image as it is, see Blunder's answer. $\endgroup$ May 21, 2023 at 20:57
  • $\begingroup$ There are tools to align 2d textures to orthographic view in Blender, in this case I'm not sure the result will be good but you can test it. See youtube.com/watch?v=Aj006df-boI $\endgroup$
    – Gorgious
    May 22, 2023 at 8:58

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Likeness sculpting or modelling is challenging especially if you have only one reference.

In your case, you need to figure out the perspective/point of view for the camera and the camera focal length but without a tool like fSpy. You can do this in Blender but you have to guess and model it by eye.

Here is a brief overview of the procedure.

Preparing the Models

Start with the default cube, make it a "block" that looks like the bounding box of the spaceship. Add a human model or Rigify's metarig to get an idea of how big your model will be.

the block

The Camera Settings

The camera has the option to use a background image. It's visible in the viewport if you look through the camera (Numpad 0). Use your reference image as the background image. The "monitor" icon allows you to switch the image on and off in the viewport. You also can define opacity and if you want to have the image in the background or in front. Try Front with 0.5 for Opacity.

Because the ship is fairly large, set the focal length of the camera to a higher value like 160, 200, or 120 - well, you have to guess here. The default is 50mm (human eye, close distance), 85 to 120 is often used for portraits (camera distance 1.5-3m), and larger values are good for long shots from far away.

You cannot apply the Location to the camera to use the world origin as a pivot point but you can use the 3D Cursor (. > 3D Cursor). Make sure the 3D Cursor is at the world origin (0, 0, 0) (Shift+S > Cursor To World Origin)

Finding the Correct Point Of View

Now activate the camera view, rotate it around in Trackball mode (RR), and try to move the cube to the spaceship's position.

You can edit the cube while looking through the camera and add a few edge loops, extrude faces, etc to adjust the shape.

finding the point of view, part1

Here is a try, and as you can see the ship seems to be rotated a bit and doesn't match the reference on the right.

Tweaking the Model's Orientation

To fix this, parent the camera to the cube object (Ctrl+P Parent To > Object), then rotate the cube/ship. If you're happy, clear the parent of the camera (Alt+P Clear Parent > Clear and Keep Transformation). Then reset the cube's Rotation (Alt+R) to have it align straight and neat in 3D space again. The camera will stay in position.

align the ship better

Add more details to see if the model fits the reference. You also can UV unwrap the model and stencil the reference image on the model with the camera activated to get an impression of where it differs and to get a "preview texture" (useful for portraits).

Viewport Example

Here is the model in the viewport with the viewport's default focal length of 50mm. You can change this in the side panel. The camera is in the distance for the long shot.

model in the viewport

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