Tutorial 1 – Sketching, Extrusion & Curves

  • Download project files for this tutorial here (52 Mb);
  • A video of this tutorial is available here;
Introduction
  • VideoTrace allows the user to generate 3D models from a video sequence by tracing planar faces on the frames.
  • Faces are constructed using the Sketch Tool Image:32px-Png_pencil.png longdesc=.
  • When a new face is added, the underlying engine estimates its 3D position.
  • Estimation will be most successful for faces which have distinguishing features, are visible from a few different angles, and are not obscured by other objects.
  • After adding a face, you should check that its position has been estimated correctly.
  • Estimation results can be inspected by scrolling through the video sequence, or by rotating around the object in the Virtual View Image:Tb_virtual.png longdesc=.
  • Vertex positions can be adjusted by using the Anchor Tool Image:32px-Png_standard_anchor.png longdesc= to manually specify their positions in a few frames at different angles.
  • Once a face has been correctly positioned, continue modelling by adding connecting faces, or by using the Extrude Tool Image:32px-Png_extrude.png longdesc= or Mirror Tool Image:32px-Png_mirror.png longdesc= tools to turn the face into a solid 3D shape.
  • These tutorials will demonstrate the VideoTrace modelling process.
1. Loading the project
Use the ‘File|Open Project’ command in the menu bar to open the file ‘block_tutorial.vtp’.
2. Tracing faces
Three-dimensional structure is built by using the Sketch Tool Image:32px-Png_pencil.png longdesc= to trace planar faces in the image.
Image:BlockTut1-Cropped.jpg longdesc=
Define the edges of the front face of this block by clicking on the corners in sequence. Image:BlockTut2-Cropped.jpg
To close the face, click on the first corner. The green edges will turn blue when the face is complete. Image:BlockTut3-Cropped.jpg
3. Extruding faces
Faces can be turned into solid models by extruding them along a line. To extrude a face, select the Extrude Image:32px-Png_extrude.png longdesc= and click on the corner of a face or the face itself.
Image:BlockTut5-Cropped.jpg longdesc=
Drag the mouse to extrude the face and align it with the image. To inspect the result, change the view by moving the mouse scroll wheel, or dragging the scroll bar at the bottom of the window. The extrusion can be adjusted by further clicking and dragging with the Extrude Image:32px-Png_extrude.png longdesc=. To complete the extrusion, click the Commit button at the top of the window, or select another tool. Image:BlockTut7-Cropped.jpg
To construct the next object in the scene, start by moving to a side view of the stair-shaped set of blocks. Image:BlockTut8-Cropped.jpg
With the Sketch Tool Image:32px-Png_pencil.png longdesc=, click on the corners to trace out the edges of the stairs and add a new face. Image:BlockTut10-Cropped.jpg
Extrude this face to complete the new object. Image:BlockTut11-Cropped.jpg
4. Adding curves
To model the blue blocks, begin by tracing the front face with the Sketch Tool Image:32px-Png_pencil.png longdesc=.
Image:BlockTut12-Cropped.jpg longdesc=
Select the Curve Tool Image:32px-Png_pencil_curve.png longdesc= and click on the top edge of the face to add a curved edge. Image:BlockTut13-Cropped.jpg longdesc=
Drag the mouse to set the shape of the curve. Image:BlockTut14-Cropped.jpg longdesc=
Click on the curve and drag again to adjust its shape. Image:BlockTut15-Cropped.jpg longdesc=
Extrude the face to complete the object. Image:BlockTut16-Cropped.jpg longdesc=

You’ve now created a 3D model in VideoTrace. You can generate textures for the model(s) from the images using the tools under the ‘Tasks’ menu, and export it from the ‘File’ menu.