Tools

Mask

The Mask tool is used to mask portions of the reference mesh at vertex level. The masked areas can be used in conjunction with other features, such as automatic retopology, mesh extraction and so on.

It uses the tablet pen pressure to mask areas at different intensity levels.

Guide Lines

The Guide Lines tool is used to draw strokes on the reference mesh and establish the overall edge flow, as a guide for creating geometry.

If you want to have the strokes symmetrical, check the Enable Symmetry option from the Options menu. The Steady Mouse feature will help you create smoother lines, by averaging the mouse position as you draw.

Create

This tool is used to create vertices and edges. As you place vertices over the reference mesh, the edges will be created automatically between them.

When triangles or quads are detected, they are added automatically.

One of the many advantages of using TopoGun for retopologizing is the fact that it lets you thing in edgeflows and worry less about polygons. You don't create polygons, but vertices and edges, and TopoGun takes care about adding/deleting the faces in realtime.

When the Make Faces tool option is enabled, TopoGun will try to connect an extra edge for each vertex you place, making it easier to create the polygons.

As you place vertices, you may want to end the current loop and start a new one. Just right click in the viewport twice, to switch to the Edit tool and then back to Create.

In case you want to change the active vertex (the one that TopoGun will create an edge to, after we place a new vertex), hold Ctrl and left click on it.

If you want to split an existing edge, hold Shift while you left click on the area you want to place the new vertex.

Right after you create a new vertex, if you want to better pinpoint its position, move it before releasing the Left Mouse Button.

You can move the active (last added) vertex even after you released the Left Mouse Button, with the Middle Mouse Button.

Edit

The Edit tool is used for operating simple modifications over the retopologized mesh, such as selecting and moving components, creating edge loops, collapsing edge rings, soft selection editing, symmetry options, and different marquee selection modes.

Use the right mouse button to switch between the Create and Edit tool.

Vertices can be selected and moved with the Left Mouse Button.

To weld two vertices, select one of them and move it onto the second one while holding the Ctrl key.

You can select vertices, edges and faces with the Edit tool. To switch between the three selection modes, press 1, 2 or 3, respectively. If you only want to toggle one selection mode, hold Shift while you press the associated hotkey.

To make multiple selections, left click and drag over the components.
Holding Shift will toggle the selection. Ctrl + Shift will force select the components and if you hold Ctrl, you will deselect the components.

If you have multiple components selected, the transform gizmo will be visible. You can disable it via the Transform checkbox in the Tools Options panel.

The transform gizmo allows you to move, rotate and scale the selected components.

When in the edges selection mode, notice that the cursor has an R or L letter next to it, as you move it accross the center or extremities of an edge.
Double click on the edge when R is displayed, to have the entire edge ring selected.
With the edge ring selected, hold Shift and MMB drag towards the center of the edge. An edge loop will be created.

Double click on an edge when L is displayed, to have the entire edge loop selected.
With the edge loop selected this way, hold Shift and MMB click on the edge center. The entire edge loop will be deleted.

Draw

The Draw tool helps you create geometry by drawing guide strokes. There are three drawing modes available: the Line, Loft and the Sweep.

The Line mode is used to create geometry by drawing intersecting strokes. At each intersection between two strokes there will be a vertex created. The vertices are connected with edges and the faces will be detected automatically by TopoGun.

Start drawing a stroke by holding down the Left Mouse Button and releasing to end it.

After you press the Create Geometry button and TopoGun evaluates the currently drawn strokes, make sure you reset the tool by pressing the Clear All button.

You can select a stroke with the Right Mouse Button and delete it by pressing Clear Selected.

After each drawing and creating geometry step, make sure you click on Clear All, to have the strokes deleted, so next time you won't get duplicate geometry.

You can create lofted geometry using the Loft mode. Start by drawing a couple of parallel strokes. You have to set the Points parameter to a value greater than one.
After drawing the parallel strokes, select the Loft mode and draw a stroke that intersects each of the parallel strokes.
The loft line indicates to TopoGun the direction in which it should detect and create the lofted geometry. Click the Create Geometry button to generate the lofted geometry.

The Sweep mode helps us retopologize tubular parts, such as fingers, limbs and tails.
You need to draw a Sweep line along the cylindrical part and TopoGun will create a cylindrical mesh wrapped around it, with a given number of segments along it's length (the Points parameter) and along it's section (the Sweep Steps parameter).

Each line can have a user defined number of Points ranging from 0 to 50. These are called sampling points. After clicking the Evaluate button, a vertex will be created at the position of each sampling point, and all the adjacent vertices will be connected by edges.

This is useful for creating base edge flow lines, with equally spaced vertices. Enable the Steady Mouse option to get smoother lines.

Bridge

With the Bridge tool, you can create "bridge" edges and/or quads, between border vertices.

The Edges mode connects pairs of unconnected border vertices, with edges. Click the Left Mouse Button to create one edge at a time, or click and hold the Left Mouse Button, then drag it between the border vertices, to have the edges created as you move the cursor.

The Faces mode works like the Edges mode, except it creates quads between pairs of connected border vertices, instead of Edges.

Use the Freehand Lines mode to create vertices along a stroke you draw with the Left Mouse Button. The new vertices will be connected by edges, with the closest border vertices.

In the Straght Lines mode, the vertices are created along a straight line you draw with the Left Mouse Button. Each newly created vertex will be connected by an edge, with the closest border vertex.

Slide

The Slide tool moves the vertices on the selected edges accross the adjacent faces shared edges.

Double click on an edge to select the entire loop, or single click with the Left Mouse Button to select individual edges. Hold Shift while you click on the edges to select or deselect them.

Click and drag with the Left Mouse Button on any vertex from the selected edges to slide all the selected edges's vertices.

Click anywhere outside the mesh to clear the selection.

Tubes

The tubes tool is used for retopologizing cylindrical parts, such as limbs, fingers, tails.

Click and hold the Left Mouse Button, then draw the sections over the mesh, in the order they should be connected to each other.

You can control the number of segments by changing the Divisions parameter. Hold Ctrl while you rotate the Mouse Wheel to change it.

Brush

With the Brush tool you can modify multiple scene vertices at once. You can move, select and relax the vertices by chosing one of the existing brush modes.

The brush Size can be quickly modified by holding down the Right Mouse Button and moving the cursor. If you hold down the Shift key while holding down the Right Mouse Button, you will modify the brush Falloff. The brush Strength can be modified by holding down the middle mouse button while moving the mouse cursor.

The Brush tool has seven working modes:

• Move: The vertices are moved and projected back on the reference mesh surface.
• Relax: Averages each vertex position based on the positions of its neighbours. It can be accessed from any other Brush mode by holding down the SHIFT key.
• Inflate: In Inflate mode, you move the vertices along their normals directions. If you hold down the Ctrl key, the vertices are pushed back along their normals directions.
• Standard: Moves the vertices towards the camera position. If you hold down the Ctrl key, the vertices are moved away from the camera.
• Screen Project: Projects the vertices back on the reference mesh along the screen space direction.
• Conform: Moves the vertices to their closest positions on the reference mesh.
• Pinch: Moves the vertices towards the brush center and then they get projected back on the reference mesh.
• Select: Used to make quick vertex selections. Hold the Ctrl key to deselect the vertices.

Extrude

The Extrude tool is used to extrude groups of border edges.

You can select the edges to extrude with the Extrude tool. By left clicking on an edge, it gets selected and the previously selected edges get deselected.
To select multiple edges, hold down the Shift key while selecting. If you already have more edges selected and need to deselect some of them, hold down the Shift key and click on the ones you want to deselect.
If you hold down the Ctrl and Shift keys while selecting, the edges you click on get selected and the Extrude tool manipulator moves to the center of the edge you clicked on.

To select all the border edges in the current shell, double click on any of the border edges that belong to the shell.

Extrude has three working modes:

• Crawl: Extrudes the selected edges and reprojects the vertices back on the reference mesh in realtime, as you move the manipulator.
• Project Back: Extrudes the selected edges and reprojects the vertices back on the reference mesh as soon as you release the manipulator and finish extruding.
• Free Move: Extrudes the selected edges without reprojecting them back on the reference mesh.

Slice

The Slice tool is used to cut through geometry, via an user defined plane.

Start by holding the Left Mouse Button to define the starting point, move the cursor to where you want the end point to be, then release the mouse button. The start-end points will define the cutting plane and all the edges intersecting it will get cut.

By default, the Slice tool detects the front geometry and the connected backfaces. If Deep Slice is enabled, it will cut all the way through.

If Extended Slice is enabled, it will slice all along the slice line, not just between the two ends.

When Force Faces is enabled, extra edges will be created, so that there will be no holes left in the geometry.

Cut

The Cut tool is used to split polygons in a more advanced way than with the Create tool.

You can cut over multiple edges (as long they're not border edges).

It has two working modes:

• Lines: You define the cut points one by one, with the Left Mouse Button.
• Freehand: You draw a stroke with the Left Mouse Button. At each intersection point between the stroke and the edges, there will be a cut point.

When the Make Quads option is off, edges will be added automatically, to avoid holes in geometry (TopoGun only accepts triangles and quads as valid polygons). Many of the new faces will be triangles.
To avoid this and create only quads, enable the Make Quads option. Extra vertices will be added to ensure that the faces are quads.

The Relax Corners option averages the extra vertices positions, so the cut looks smoother. It applies only to the vertices added to ensure that all the new faces are quads.

Circle

The Circle tool is used to retopologize circular, disk shaped parts of the reference mesh.

You start by clicking and holding the Left Mouse Button on the reference mesh, where you want the circle to be positioned. Once you define the radius, release the Left Mouse Button.

The circle is drawn in screen coordinates and you can reposition the mesh after you defined its radius and position.

If Geo Steps is enabled, then the geometry will be created inside the circle. When the option is off, there will be no inner geometry, but only border vertices, interconnected by edges.

Enable the Inverted Draw option, to define a point on the circle first, then the circle's position.

Shell

The Shell tool is used to add thickness to thin reference mesh parts, such as clothing and armour.

This tool works only on parts of mesh with border edges (shells).

You start by selecting a control vertex, used to set the mesh thickness. While holding the Ctrl key, a red dot is rendered at the location where the control vertex normal intersects the reference mesh. If you left click near the red dot, you'll set the thickness close to the distance between the control vertex and the intersection point.

Click and hold the Right Mouse Button and drag it to the right or left to increate or decrease the currently set thickness.

By default, the extruded mesh will have a constant thickness. If you disable the Uniform Thickness option, the new vertices will be reprojected on the reference mesh.

Patch

Patch is a complex tool, used to create mesh patches with dynamic automatic topology. It is considered a hybrid between manual and automatic retopologizing.

You start by drawing lines (strokes) over the reference mesh. Based on how the lines endpoints overlap, patches are created and automatically tessellated into quads and sometimes extra triangles.

Each line has a number of divisions which dictate the patch geometry density and topology.

Each patch can have between two and six sides (lines).

Click and hold the Left Mouse Button to draw a new line.
If you start or end the line near another line's extremity, the two lines will be connected.

Use the Right Mouse Button to select a line.

If you want to delete all the lines, click on Clear All in the tool options panel.
Click on Clear Selected to delete the selected line only.

You can change a line's number of divisions by selecting it first, then adjust the Selected Divs value.
The default number of divisions for each new line is set by the Default Divs parameter.

Hold Ctrl and use the mouse scroll wheel as an alternative way to change the number of divisions. There's no need to select the line in this case, just hold the mouse cursor over it.

To reset the selected line's number of divisions, click on Selected Divs button. It will set the division count to the Default Divs value.

To set the default number of divisions for the new lines to be equal to the selected line's value, click on Default Divs.

You can select a patch by right clicking on the circle in the center.
Click on Prev Pattern or Next Pattern to change the patch's automatic topology pattern and click on Enable to enable/disable the selected patch. When a patch is disabled, no geometry will be created from it.
You can also change a patch topology pattern by holding Ctrl and the mouse cursor over the patch center, while rotating the mouse wheel.

Any patch line can be shared between two patches. The resulting border geometry will be automatically stitched.

To have the patches evaluated and the geometry created, click on Create Geometry or press the Enter (Return) key.

You can extend the existing geometry by creating geometry lines. Start from a border vertex, hold the Left Mouse Button and release it when it's on the desired ending border vertex.
The resulting geometry line is rendered as red and each division point lies on a border vertex position. You can't change the number of divisions for the geometry lines.
The patch geometry will be stitched to the existing geometry where there are geometry lines to make the connections.
Another way to create a geometry line is by selecting two border vertices which will be the line's endpoints and then click on Add Geometry Line. Note that there should be an edge path between the two vertices.

Sometimes you may not consider creating geometry lines. Disable the Allow Geometry Lines option in order to achieve that.

In order to have quads only geometry created from a patch, the sum of patch's divisions should be an even number. Otherwise, a triangle will be added on the patch topology.
If you don't want this behaviour, disable the Allow Triangles option. Only the valid, quads only patches will be taken into consideration.

When you have multiple adjacent patches and don't want any triangle created, it's often difficult to set each line's divisions count so that each patch will have an even number of divisions.
Click on Optimize For Quads to achieve that. TopoGun will attempt to adjust the division count for each line so that all the patches will create quad only geometry.

Straight Lines Mode

The default patch lines drawing mode is Free Hand.
For hardsurface reference mesh parts, you can use the Straight Lines drawing mode.

Click and hold the Left Mouse Button to set the line starting point, then release it where the line should end. A straight line is created, then projected on the reference mesh surface.

Loft Mode

While Loft Mode is enabled, after each line is drawn, two lateral lines are created between the new line and the previous active one.
This way, a rectangular patch is created automatically.

The active loft line is rendered in green. Each time you draw a new line, it becomes the active loft line.

Use the Right Mouse Button to select and set a new active loft line.

When Allow Loft Geometry Lines is enabled, a geometry loft line is added if the active loft line and the previous one are connected to border vertices.
The loft geometry will be stitched to the existing geometry via the loft geometry line.

By default, each loft line has a Loft Divs number of divisions, no matter the length of the line in question. This can lead to some odd and stretched loft lines and inconsistent resulting polygons size.
When Auto Loft Divs is enabled, the Loft Divs parameter is ignored and the loft lines will have a variable number of divisions, based on their length, to better match the active loft line's division size.

When Auto Loft Divs and Constrain Loft Sides are enabled, each loft line will have the same number of divisions. If a loft line is way shorter than its counterpart, there will be a visible difference in division length between the two lines.

If Constrain Loft Sides is disabled, the two loft lines will have a different number of divisions, based on their lengths. The downside is that the resulting geometry will not have a very clean and predictable edge flow.

When From First Line Only is disabled, the loft side lines divisions are based on the active loft line division length.

As the active loft line gets shorter, the number of side lines divisions is increased, to match the active loft line's division length. The resulting polygons won't necessarily have an uniform size.

Enable From First Line Only to have the loft lines division length based on the first active loft line only. This will result in more uniform sized polygons.

When Loft Mode is enabled, you can change the number of divisions on any line, just like you'd to in the default working mode.

Editing Patch Lines

You can smooth a patch line with the Left Mouse Button, while holding the Shift key. All the line's points are projected back on the reference mesh surface.

If you want to extend a line, first select it with the RMB, then continue drawing it, by starting from one of its extremities.

Click Close to extend the selected line so that its extremities overlap.

If you want to cut a line, first select it with the Right Mouse Button. Make sure you click on the point you want to perform the cut. A small white dot will indicate the line cut position. Next, click on Cut to have the line cut in two.

Use the Split function to have two overlapping lines split in four, at their intersection position. First select one of them, then enable the Intersect option.
As you move the cursor over the second line, you notice that the intersecting point turns green. Left click to perform the split.

If a line has one of its endpoints overlap with another line's endpoint, you can have them fused together in one line.
First, select one of the lines and enable the Weld option (or hold Ctrl), then left click on the second line's overlapping endpoint.

When working with symmetrical reference meshes, it can be very difficult to draw lines that lie on the active symmetry plane.
To fix a line and put it on the "zero" symmetry position, select it and then click on Project On Symmetry Plane.