How do you determine the vanishing point/horizon when compositing two layers in HitFilm?

Anthony_VFX_CGIAnthony_VFX_CGI Website User Posts: 55
edited November 2018 in General

Does anyone have a way to determine the vanishing point and horizon on a layer in HitFilm?

When composting two footage layers, I would love to be able to draw lines on each layer (following geometry in the footage) to determine their vanishing points. Then  set their anchor points, and match their horizons exactly.  This would be tremendous when positioning foreground and background layers in a composite  

I haven’t found an easy way to do this. The closest I come is by drawing an unclosed mask. But I cannot see two  unfinished masks on two separate layers at once.  

Thoughts?

 

Comments

  • Triem23Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 18,254 Ambassador

    Grid filter for finding horizon. Lightning and/or lightsword for straight lines. Turn the glows to zero on both. For lightning, turn wave and twitch scale to zero. Build your guides over a BG plate, then select all line layers and convert to a Composite Shot to collapse the guides to one layer. 

  • FilmSenseiFilmSensei Moderator, Website User, Ambassador Posts: 2,297 Ambassador

    Lightning would be better for the lines because it doesn't take as many resources to produce as Lightsword. Being able to work faster and smoother is good. Either one would work well because you could assign them to Points that would be the vanishing points.

  • Anthony_VFX_CGIAnthony_VFX_CGI Website User Posts: 55

    Thanks fellas! I found the lightning effect winnowed down to a line was the most helpful suggestion to draw on a layer to determine the vanishing point of the content geometry. From there I can easily determine the horizon.

    As a side note, I've found the grid effect really superfluous to determining the horizon. That is, whenever the grid works, the horizon is usually easy to discern by eye from the image itself. 

    Not entirely sure what you mean Mike about making all the lines on a background plate. How then would I go about matching the foreground plate? In other words, once you make the vanishing point the anchor point for the foreground and background layers (using the lightning effect you suggested), how would you go about matching anchor points between two layers exactly? (I don't think "pre-comping" them yet is in order, as we'd still have to adjust them to match.) Am I misunderstanding what you meant?

  • Triem23Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 18,254 Ambassador

    I may have explained badly. 

    Let's say the background plate is an image you need to match perspective on. In this case the perspective lines are the foreground plate (cuz you need to see them) and all composited elements are midground. 

    Basically is placing the lines on the foreground using background for reference. So if the BG has, maybe a skyscraper, you can use the roof as reference to draw that first grid line to find the vanishing point. 

    It's really like in traditional art where you'd use a grid, ruler and angled lines to build perspective guides  but, in Hitfilm you have to create points to hang lightning on.

    The pre-comp is more for when you're done. Since you end up hanging lightning on points often, you could end up with a dozen point layers or more. Pre-comping the guides just cleans the layer stack up a bit.

    I didn't think of this the other day, but consider planes with grid in 3D space! You can rotate that grid in three dimensions to line up the ground plane and other elements. 

  • Anthony_VFX_CGIAnthony_VFX_CGI Website User Posts: 55

    I see. That makes more sense. Thank you!

    ...I found a tutorial explaining in AE what I am trying to do in HitFilm. Determining the horizon via the vanishing point starts around the 6:00 mark.

    https://www.youtube.com/watch?v=Y3RJGepqOAE

    I find using the lightning effect to draw lines an easy workaround. At this time, I am just trying to exactly match the anchor points of two different layers (foreground and background). Since the anchor points were derived from the vanishing points (and the horizon of each layer sits on their respective vanishing point), it's all about matching anchor points now to get the horizons of each layer to sit on each other.

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