MegaShapes Simple Loft


This is the simple version of the mesh lofter in the system, it uses a single shape to define the path along which the cross section path will be ‘lofted’. This layer and its brother the complex loft form the core of the MegaShapes system as these will be the most often used layers and will usually form the base upon which other layers will be built. In the picture above of the Mega Moo National demo scene the grass and soil mesh underneath were built using the simple loft layer. Both the path and cross sections can be open or closed shapes, and if the chosen shape has more than one spline you can pick the curve to use. The options for this layer allow you to easily define where along the path the mesh is to start and how far along the build from that point. There are values to control the smoothness of the generated mesh along and across the surface as well as options to cap the ends on open splines, and full uv mapping options.

The inspector of this layer is made up of five sections, first controls the basic mesh generation settings, then a foldout for the cross section params, some advanced params, uv mapping and finally capping.

Simple Loft General Params


The general params for the simple loft, these control the path to use, the start and length of the layer as well as options to scale, rotate and offset the layer.

Name

Name of the layer.

Enabled

Un checking this will remove this layer from the loft object and hide most of the inspector for it.

Col

Color to tint the inspector for this layer, makes finding the layer you want easier on complex loft objects.

Lock

Sometimes you will want to have the loft object update in realtime but maybe not all the layers actually change, if you check the Lock option then during a rebuild the layer will not recalculate its contribution to the mesh but will just use the last lot of vertices it built so greatly speeding up the mesh creation for entire object. So useful if you have a complex race track loft object and just want to deform a crash barrier layer from it, so you would lock all the layers except for the one to change, update that then lock it again.

Material

The material to use to render the faces built by this layer.

Path

The path along which to loft the cross section shape.

Curve


If the selected path contains more than one curve a slider will appear allowing you to select which curve to use.

Start

The start position along the path shape to start building the layer, 0 is the start 1 is the end, values outside this range will either loop for closed shapes or extrapolate past the ends on open shapes.

Length

The length of the loft along the path, 1 is a full length of the path loft, the length value is added to the start value to find the actual end value, so if this is outside the rang 0 to 1 then the layer will either loop or extrapolate past the ends of the path.

Dist

This is how far to step along the path before building a new line of vertices, the smaller this value is the more vertices are produced and the smoother the end result.

Offset

The loft can be offset from the path by changing these values. Also there is an option to control the offset along the length of the loft from curves for the X, Y and Z directions.

Use X Offset

Check to use a curve to define the amount of x offset from the path along the length of the path shape.

Offset X

The curve to describe the amount of x offset.

Use Y Offset

Check to use a curve to define the amount of y offset from the path along the length of the path shape.

Offset Y

The curve to describe the amount of y offset.

Use Z Offset

Check to use a curve to define the amount of z offset from the path along the length of the path shape.

Offset Z

The curve to describe the amount of z offset.

Cross Params


The params that control the cross section of the loft, such as the shape to use, and scaling options.

Section

The shape to use as the cross section.

Curve


If the selected path contains more than one curve a slider will appear allowing you to select which curve to use.

Snap


Sometimes the curves in a shape are not aligned nicely, so you can check this to automatically snap all the curves in shape so that the first knot of each curve is in the same position before being used in the layer.

Cross Start

The start position along the section to shape to start the loft from, 0 is the start of the shape 1 is the end, values outside 0 to 1 will either loop or extrapolate the shape.

Cross Len

How far along from the start to build the layer to.

Cross Dist

The distance to use to make the next vertex at along the cross section, lower values will result in a smoother mesh and more vertices.

Cross Rot

You may want to rotate the cross section before it is used in the layer creation, you can define any rotation you want here.

Cross Scale

You can also scale the cross section before it is used.

Pivot

The local offsets of the knots can also be changed before the shape is used in a layer, useful to line up sub curves in a shape.

Include Knots

If the Cross Dist value is quite large you can lose some of the detail in a cross section, if you check this option then the cross section will include all knots on the shape in the cross section regardless of cross dist, this is also handy to make sharp edges for say a wall.

Use Scale Curve

The amount of scaling of the cross section can also be curve driven for the length of the layer, check this to allow use of a curve to drive the scaling.

Scale

The curve to define the scale along the length of the loft layer.

Offset

The scale curve can be quickly offset along the path by adjusting this value, useful for simulating say a ball being squeezed along a bulging pipe.

Separate Scale

You may want to have a separate scale curve driving the X and Y scaling, check this to enable a separate scaling curve for the Y axis.

Use Scale Curve Y

Turn on the use of the second scale curve for the Y Axis.

Scale Y

The curve for scaling the Y Axis

Offset

The offset along the layer path for this Y Axis scale curve.

Advanced Params


These options can have a dramatic effect on the end shape of the loft, it allows you to extend the loft up or down so either the top or bottom of the loft line up which is useful for doing say rolling hills or tree lines. And there are options to clip the loft so that you can define a flat top or bottom region of the loft, best way to see what these do is to have a play with them.

Flip

For some reason you may not get a mesh that you expected out of the loft, or you may want to produce a tunnel type loft, if so then checking this will reverse the face order of the mesh effectively turning it inside out.

Snap Top

This will adjust the loft so it is stretched so that the top of the loft will lay be of the Top Value.

Top

The value the top of the loft will use.

Snap Bottom

This will adjust the loft is stretched so that the bottom of the loft will lay be of the Bottom Value.

Bottom

The value the bottom of the loft will use.

Clip Top

This will clip any points above the Clip Top Val to that value so causing the top of the loft to be flattened.

Clip Top Val

The value above which any vertex will be clip to.

Clip Bottom

This will clip any points below the Clip Bottom Val to that value so causing the bottom of the loft to be flattened.

Clip Bot Val

The value below which any vertex will be clip to.

UV Params


The options that control the UV mapping of the layer for textures.

UV Off

The Offset into the texture map to start the mapping from.

UV Scl

The Scaling of the UV coords, smaller values will zoom in on the texture map, values greater than 1 will start to tile the texture, negative values will flip the texture.

Swap UV

Will swap the u and v parts of the mapping.

Physical UV

If this is on then the actual vertex values will be used for the mapping, this can make it easier for some mapping cases it will also mean that the uv mapping will keep the scale of the texture map constant, so if you expand a loft the texel size will remain constant.

Cap Params


If the path you loft along is not a closed shape or you are only using a portion of a shape then you may want to cap the ends of the loft, and these options allow you to do so and define the material and uv mapping for each end cap.

Cap Start

Allows a mesh cap for the start of the loft mesh to be generated.

Material

Material to use for the start mesh cap.

UV Offset

Offset value to use on the caps UV’s

UV Scale

Scaling value to use on the caps UV’s.

Rot

Angle to rotate the start cap UV’s by.

Cap End

Allows a mesh cap for the end of the loft mesh to be generated. The params are the same for the start cap.

Tutorial 1: Create Simple Loft

Tutorial 2: Advanced Params

Simple Loft Layer Features Video

A little video guide to the simple loft layer and what some of the params do.

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