advanced modelling techniques

ArtCAM Pro User Group 2004

Advanced Modelling Techniques

IntroductionThis section will deal with a variety of advanced modelling techniques to create different relief effects. The techniques here will try to show a variety of different shapes, some will be individual techniques and some will be complete modelling projects. The idea in this section is to show how different tools in ArtCAM can be used in combination to produce the parts you require.

All the files for this project are under the Friday presentations in; “4 – Adv_Modelling/Demo Files”, each project has its own named sub-folder with the files for that project contained in it.

1 Creating a Rising Spiral Shape

Up until version 7 it was very hard to make a shape with a spiral that rises up in z at the same time. The introduction of the multi cross section 2 Rail Sweep makes this much simpler to create. Ann application of this idea is shown in the picture below right.

Open the file “1 Spiral-no model.art”

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User Group 2004 ArtCAM Pro

The file is pre-prepared with vectors that were drawn in ArtCAM. The Spirals were created from sketching vectors over a photograph of a part with the same design. In the middle of each spiral is a circular vector. The boxes to the left will be the cross sections of the model. In order the first is 1 inch high, the second 0.8 high, the third 0.6 high, the fourth 0.4 high, the fifth and sixth 0.2 high, the seventh 0.4, eighth 0.6 and final one 0.8. Each section is 1 inch wide.

The cross sections will be applied from the centre of the top spiral down to the centre of the bottom spiral.

Picking from the part which joins top and bottom spiral. Hold the “Shift” key and select the left side first and the right side second

Still holding “Shift” select the cross sections individually, along the top level left to right and then along the bottom level left to right

The order of selection is very important as it dictates the order the shapes will be used by the new Shape Editor. First two vectors will be the rails and the subsequent vectors will be the cross sections used in the order they are selected. If you box select rather than individually select then you cannot control the order they will be used.

Hit the 2 Rail Sweep icon

You should see the vectors labelled up as in the image below, check the cross sections are numbered 1 to 9 in order. Do not worry about the numbers on the rails at the moment.

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At the moment the cross sections positions on the rails have been created automatically. The most powerful part of the new 2 rail sweep is not just that it uses multiple cross sections but that you can accurately position them as well. At present only the start and end cross section positions are correct (at the ends).

The position and smoothness of each cross section can be edited from the Status area of the menu. This is shown in the image below.

This also gives you useful information about the curves selected and whether they are valid or not. Under Cross Section you can see the number 1 on the left of the menu. Looking across from that it is valid. The next icon with the arrow can be clicked to re-position the cross section. The curve can be toggled to determine whether the sweep at that point will smoothly blend through the point or linearly. The red X allows the curve to be deleted if you find it was not needed. For this example Cross Section 2 through 8 need to be re-positioned.

From the Status area of the menu, click on the Position icon for Cross Section 2, when you click it the word position changes to 1st Rail

Click on the first rail (the one labelled with the red numbers – zoom in to make sure you know which one this is) to position cross section 2, see the image below for where this should be

Click on the opposite point on the other rail for the 2nd point

Top left image shows the line between rail 1 and 2 for cross section 2, the image on the right shows the number 2’s in place after the c./s has been positioned (highlighted in the red box).



Continue working through the rest of the points (the last one to position is the eighth). The image below shows the approximate positions, the green lines are drawn in to help you position them. Ensure that you are always clicking the rails in the right order, track along the vector from the last red point to see which rail you should click first for the next point.

Uncheck Scale Height with Width (the height of the cross sections will control the depth)

Check Add and hit Calculate



The part that is created is shown in the image below.

Have a look at the model and see how the part has been created. If you do not like the flow of the shape, undo the function and change positions of the cross sections and re-calculate. Make sure you do not exit the 2 Rail Sweep function as the cross section positions are not remembered. As long as you keep it open you can iterate with different solutions (even saving them in between undoing and trying again). You can remove and reposition cross sections as much as you want. There could also be solutions for this using a Z modulation curve or using less positioned cross sections.

To finish the design;

Pick the circle vector in the middle of the top spiral, hit “F12”, enter a Start Height of 1 and click Merge Highest

Pick the circle vector in the middle of the bottom spiral, hit “F12”, enter a Start Height of 0.8 and click Merge Highest

The model is saved at this stage and is called “1 Spiral.art”. Depending on the finish you want this can either be smoothed (the whole relief) as it is or you can blend the edges of the circles into the spirals with the sculpting tools.



2 Creating a Hand Carved Edge on a Relief

When shapes are carved by hand there is often a slightly indented carved edge on them. This effect could help to add effect to your CNC carved reliefs, or at least provide a base if you wanted to create them it and then actually hand carve it. This could be produced easily on smaller parts by using the sculpting tools around the edge of the relief and using colours to mask it. However on large parts this would be very time consuming to go around every edge. This process will work on any sized part with a blank background. The effect can be seen around the edge of the part in the image below.

The part that will be used is a simple Celtic weave relief, as it has a lot of internal detail it will show how this technique works automatically on all the edges. So start you load the basic relief that you want the effect on and go from there.

Open the file “2-HC-Main Relief.art”, this is the basic relief that will be used

From the Model Tab select Greyscale From Relief Reset the Relief Double click yellow, in the Shape Editor select Round, Angle 30, Limit to

Height 0.1 and hit Add

The angle and limit height will determine how far from the edge the carved effect will be created. A shallower Angle and larger Height value will create a more pronounced effect that stretches further from the edge of the original relief. Once created the shape needs to be moved down by the limit height so the top of the bulge becomes zero.

Still in the shape editor select Flat Plane, Start Height 0.1, Subtract

The model is moved down, so the top is now zero, the next stage is to remove part of the shape that has been created. The effect of the carving only needs to be around the relief itself not the edge. So the shape at the edge needs to be eliminated.



From the Model Tab select Greyscale From Relief Draw two rectangles, one inside the grey at the edge of the model space

and one outside of it, as in the image below

Select both the vectors, hit “F12” and select Zero From the Model Tab select Greyscale From Relief, you will see the

edges are now level Delete the two rectangles Save the art file with a new name (it is saved for you and is called “2-HC-

Dip Shape.art”) Reset the Relief

At this stage a random carved texture needs to be created on the area of the model, you can either do this your self or a file is provided to texture the model to use. This file could be used on parts up to 96x48 inches.

From the Model Tab select Greyscale From Relief, everything should turn yellow

Select yellow as your primary colour From the Relief Editing tab select Texture Relief Check Whole Relief, check From File and hit File… Select “2-HC-randomcarve.rlf” and hit Open Change the Height to 24 (as this model is smaller it is good to tighten up

the texture a little) and hit Add Switch to the 3D View to see the texture relief From the Relief Editing menu select Scale Relief Height, check Whole

Relief and enter a New Height of 1 and hit OK

The file is saved at this stage and is called “2-HC-carving Shape.art”



The carving will be Relief Multiplied with the dip shape that was created earlier to limit its height and effect to the area around the relief.

From the Relief drop down menu select Load and Multiply Select “2-HC-Dip Shape.art” and hit Open

You should see the relief changes to look like the image below.

This is currently sticking upwards, so it needs to be inverted. Depending how strong an effect is required the relief can then be scaled again. Then finally it can be combined with the original relief.

From the Relief Editing tab select Invert Relief Z Only Select Scale Relief Height, enter a value of 0.15 (a large value for the

depth of relief to show the effect), hit OK Pick Load Relief, select the file “2-HC-Main Relief.art”, check Add and

hit OK

The finished part is shown above, this is saved at this stage and is called “2-HC-Finished.art”. This is an effective technique and by tweaking the values different strengths and density can be created.



3 Creating shapes so they flow from a flat plane onto an elevated part

There are often situations when a design requires the relief to be on top of part of the relief but flowing down onto the zero plane. This is a quite simple effect to achieve and in this section the process will be documented. The part that will be used to show this is shown in the image below. This is a real part of the new display that was created for the ArtCAM trade show booth.

The whole modelling process will not be covered in the documentation, just the way to achieve the effect of the parts draping over each other.

The first part of the process is to individually model the components that need to be overlapped. In this case there is a flower design which needs to slope smoothly onto a rail shape. These two parts have been modelled and are shown in the images below.

Part 1 Part 2



These parts were drawn from the same photo so are already in position. The key to this process is to decide how you want the parts to overlap, then create an underlying shape, combine the reliefs and merge them together to get the correct effect.

Open the file “3-Overlap-Part1.art” From the Relief tab select Load Relief, select “3-Overlap-Part2.art” and

hit Open, check Pasting and hit OK On the 3D Clipart menu pick the Mode tab and select Add, make sure the

box to the left Copy Outline is checked Hit Paste Look in the 3D View to see how this does not give a good effect between

the two reliefs In the 2D View select the vectors that were created during the pasting

operation, right click and pick Copy Deselect the vectors (click anywhere) and hit CTRL+Z to undo the pasting

operation, this will also remove the vectors which we need Right mouse click and hit Paste

This has provided a copy of the vectors, but without the relief which we do not need at the moment. These vectors are important as the underlying shape that is created needs to fully cover them.

Sketch a vector Rectangle so it is slightly larger than the flower outlines, as in the image below



This area will be where the underlying shape of the slope from the zero plane onto the rail needs to be defined. The next stage is to create a cross section for the underlying relief. This will define the slope from zero to the height and position of the rail.

From the Project Information on the Assistant tab note the depth of the relief, you can also hover the cursor over the shape to see this information at the bottom right of the interface, the depth is 0.3 inches

Create a vector Rectangle, snap from one side of the large rectangle to the other side, then in the menu enter a value of 0.3 for the Height

Right mouse click to create the shape and close the menu Select the new small rectangle and use the down cursor arrow to jog it out

the way of the other rectangle Hit “N” to go into node editing mode Hover over the bottom span with the cursor and hit “R” to remove the

bottom of the small rectangle Hover each side of where the rail reaches its maximum height (white) and

hit “I” to insert two points, as in the image below

Hover over each of the new points and hit “S” to smooth them Hover over the corner nodes and hit “D” to Delete them, the vectors

should now look like the image below

Drag the control point (white node) for the end nodes until it snaps in line with the start point, the vector should now look like the image below

By selecting the control points of the end nodes and the nodes on the top of the vector and using the cursor arrows left and right the curve can be edited. Adjust it to your own preference or use the image below as a guide for the finished vector



Once finished, the new vector can now be used to extrude a relief using the sides of the large rectangle.

Select the large rectangle Make sure you are still in Node editing mode Hover over the top edge of the rectangle and hit “R” to remove that span Repeat this process to remove the bottom edge as well Deselect everything Holding “Shift” select the left side of what used to be the large rectangle,

then the right side and finally the curve that was created at the bottom From the Relief tab hit 2 Rail Sweep Reverse the direction of the Second rail by checking the box, un-check

Scale Height with Width, check Highest and hit Calculate

In the 3D View you will see a relief like the one in the image below. This file is saved at this stage and is called “3-Overlap-ULshape1.art”.

This will be used to create the underlying shape for the flowers so they flow onto the rail smoothly.

In the 2D View select the Flower vector group Hit “F12”, select Zero Rest from the Shape Editor

You will see in the 3D view now the underlying shape just where the flowers are.



From the Relief tab select Load Relief, select “3-Overlap-Part2.art” and Open, check Adding and hit OK

You should see what is in the image below. This file is saved as “3-Overlap 2 and ULshape.art”.

Select Relief Load and pick “3-Overlap-Part1.art” (the original rail), hit Open, Merging Highest and hit OK

You will see the part as in the image below. This can be smoothed if required to finish it off. This concludes this project you can see how by changing the underlying shape, different effects and amounts of slope could be created. This file is saved as “3-Overlap-Finished.art”.



4 Technique for building Linen-fold (Flags and Banners) of any size and combination

This project shows how to build a classic woodworking shape, the Linen Fold, but the technique applies to many applications. It has been designed so you create pieces which could be used to create an infinite number of variations of the design. Making it with as many folds as you want, as large or small as you want, individually altering each part if required. This is also a technique which could be used to create flags and banners as well by altering the component pieces slightly. The finished design is shown below.

First the 2 components parts that will be used to create the complete design will be created. The shapes were sketched in ArtCAM from looking at an existing Linen-fold design. The vectors on the left of the file will be used to create the end piece and the vectors to the right the folds. The 2D view of the pre-created vectors is shown below.



Open the file “4-LF-Vectors.art”

This file is going to be used to build the component pieces that can be assembled to make the complete Linen Fold relief. The vectors have been organised onto 4 layers, essentially the parts will be made by using the 2 Rail Sweep and the Shape editor to zero the pieces that are needed.

Switch on the new Greyscale View from the 2D View menu bar From Layers tab, un-draw all Layers except End1 Holding “Shift” select the vertical line to the left, the vertical line to the

right and then the cross section shape below them (not the outline vector) Pick the 2 Rail Sweep icon Check Add, hit Calculate and Close Pick the outline vector, hit “F12”, select Zero Rest from the Shape editor

You should have the shape as seen in the above image.

Un-draw Layer End1 and Draw Layer End2 Holding “Shift” select the vertical line to the left, the vertical line to the right

and then the cross section shape below them (not the outline vector) Pick the 2 Rail Sweep icon Check Highest, hit Calculate and Close Pick the outline vector, hit “F12”, select Zero Rest from the Shape Editor Save the file (or you can use the one provided)

You should have the shape as seen in the image below. The file at this stage is saved and is called “4-LF-End.art”.

Reset the Relief



Un-draw Layer End2 and Draw Layer Main1 Holding “Shift” select the vertical line to the left, the vertical line to the

right and then the cross section shape below them (not the outline vector) Pick the 2 Rail Sweep icon Check Add, hit Calculate and Close Pick the outline vector, hit “F12”, select Zero Rest from the Shape Editor

You should have the shape in the image below.

Un-draw Layer Main1 and Draw Layer Main2 Holding “Shift” select the vertical line to the left, the vertical line to the

right and then the cross section shape below them (not the outline vector) Pick the 2 Rail Sweep icon Check Highest, hit Calculate and Close Pick the outline vector, hit “F12”, select Zero Rest from the Shape Editor Save the file at this stage or you can use the one provided

You will have the shape above now. This is saved at this stage and is called “4-LF-Fold.art”. From these component pieces it is possible to build an infinite number of variations of the Linen fold by pasting them into a file and changing the sizes and positions of them as you do. In this case a Linen Fold with 3 folds on each side will be created by building a ¼ of it and then saving this and mirroring the pasting it in to create a symmetrical design. Create a New Model, Height 24, Width 18, inches, Origin lower left hand

corner, suitable resolution for your PC (the example uses 1244x1658)



Switch on the new Greyscale View from the 2D View menu bar

The components will be pasted in now, the End will be pasted in the position it was created and the fold pasted in position to create the rest of the lower left hand ¼ of the relief. The part is being designed to be mirrored across the middle of the design both vertically and horizontally. So it needs to slightly overlap the middle in both directions. The parts were built in a position so they are slightly over 12 in Y (12.1). The final Fold will be pasted to put it just over the X9 (9.02) position. The effect of this will become clear when the part is mirrored.

From the Relief tab, hit Load Relief, pick “4-LF-End.art” and hit Open, check Pasting and hit OK

Hit Paste and Close, the part should look like the image below left

From the Relief tab, hit Load Relief, pick “4-LF-Fold.art” and hit Open, check Pasting and hit OK

You will see the outline of the fold, this needs to be positioned so the part which sticks out the bottom overlaps and lines up with the right hand side of the last piece that was pasted in.

Zoom in and use the Left hand cursor arrow key to move it over until it is in the position shown in the image above right

On the 3D clipart menu, pick the Mode tab, check Merge Highest and hit Paste, in the 3D View the part should look like the image below



Without Closing the 3D Clipart menu, use the right cursor arrow to move the red outline to the edge of the part that was just pasted in as in the image below left

Using the node in the middle of the outline box drag the end upwards so the edge of the outline lines up as in the image above right

Hit Paste and you should see what is in the image below (in the 3D View)

Make sure you still have the pasting outline selected, hit “T” until the Transform menu opens

Check the top right part of the box at the top of the menu, enter an X value of 9.02 and hit Apply and Close (this has positioned the right side in position), you may need to select the shape and hit “T” once to bring the transform outline up again

Use the middle node of the outline box at the bottom and left side to push the shape so it lines up as in the image below (this will squash the shape slightly)



Once in position hit Paste Close the 3D Clipart menu

You should have a relief that looks like the following image. The file is saved at this stage and is called “4-LF-Quarter.art”.

Save the file or you can use the one which is provided From the Model tab hit the Mirror Model Vertically icon From the Relief tab select Load Relief, select “4-LF-Quarter.art”, hit

Open, check Merging Highest and OK Save the file or you can use the one which is provided (it is saved and is

called “4-LF-Half.art” From the Model tab hit the Mirror Model Horizontally icon From the Relief tab select Load Relief, select “4-LF-Half.art”, hit Open,

check Merging Highest and OK

This should give you a completed Linen Fold design which looks like the image below left. The part is saved at this stage and is called “4-LF-Finished.art”. It is possible to paste in different numbers of folds and to squash and stretch them as required. It is also possible to get interesting effects by distorting the design with the Relief Envelope Distortion tool and example is shown below right.



5 Modelling a Lions face from a photo

This project shows how to create a lion’s face relief from the photograph of a door knocker. The vector creation was covered in another project, so this documentation will start with the vectors created. The vectors have been organised onto layers, the method for this will become apparent as the modelling process is worked through. Some other vectors have been created as well. One of them is the outline around the inside of the mane which was created in the same way as the face outline at the end of the vector creation project (copying then welding the vectors). A vector around the nose and surrounding area (snout area) has also been generated like this as well. The last new vector is inside the “face outline” and was just generated by offsetting that vector inwards. The use for this will become apparent too.

Essentially this is a similar process to the Wolf project from the 2003 User Group. It introduces a couple of new suggestions for building shapes and is also it is a front view rather than the side. It is another good example of how to create simple shapes and then use the sculpting tools to blend the shapes together to make a nice looking organic model.

Open the file “5-Lion-no model.art” On the Layer tab switch off all the Layers except Mane Outline

For the mane it would be good to have it slope upwards a little, so an underlying shape will be built that overlaps the true edge of the mane. This can be built up and the mane detail added, then the part which is not needed will be zeroed. As vector modelling for large areas of the model is time consuming colours will be used to model the initial shape instead.

Holding “Shift” pick the outer and inner vector Select cyan as the primary colour From the Bitmap tab select the Flood Fill Vectors icon Double click cyan and select Round, Angle 25 and hit Add, Close when

finished calculating



The relief should look like the image above.

Switch off the Mane Outline Layer Switch on the Mane Detail Layer Box select all the vectors currently visible Hit “F12” and select Round, Angle 25, Add, Close when finished

calculating Switch off the Mane Detail Layer Switch on the Mane Outline Layer Select the vector in between the outer and inner vector, hit “F12”, select

Zero and Close

The image should look like the image above, this part is saved and is called “5-Lion-Mane.art”.

Save the art file (or you can use the one provided) Reset the Relief Switch off the Bitmap Layer (2D view menu bar not an actual Layer)



From the Layer tab un-draw Mane Detail and draw the Face Detail Layer Box select all the vectors currently visible, then holding “Shift” deselect

the two large eyebrow vectors so you have the vectors selected in the image below

Hit “F12” and select Round, Angle 25, Add, Close when finished calculating

“Shift” select just the two eye brow vectors Hit “F12” and select Round, Angle 35, Start Height 0.1, Merge High,

Close when finished calculating

The part should look like the above image at this stage.



Switch off the Face Detail Layer Switch on the Nose Layer Select only the nose vector (with the nostrils) Hit “F12” and select Round, Angle 30, Start Height 0.2, Merge High,

Close when finished calculating

The Relief will now look like the above image. The next stage is to raise up the entire snout area, there is a vector to do this but it would not give an ideal shape if the shape editor was used. The focal point of the shape (the peak) needs to be at the base of the nose. So the 3D blend tool will be used.

Select just the vector which surrounds the whole nose area From the Relief Editing tab select Create 3D Blend Check Convex, under Heights enter Border 0 and Inner 0.3, check

Select Point With Cursor and hit Start, click in the 2D View towards the lower part of the nose area (approx X4.87, Y2.285), check Add and hit Create Blend

The part should look like the image above you should see how the nose area has been raised up with the point towards the bottom of the nose.



Switch off the Nose Layer and switch on the Eyes Layer Select all the vectors on the Eye Layer Hit “F12” and select Round, Angle 30, Start Height 0.08, Merge High,

Close when finished calculating Switch off the Eyes Layer and switch on the Face Outline Layer Select the green as your primary colour Select the vector and from the Bitmap tab select Flood Fill Vectors Double click green Hit “F12” and select Round, Angle 20, Start Height 0.18, Add, when

finished calculating hit Close

The relief should look like the image below, the last shape was to raise up the whole face and add more roundness to it. The part is saved at this stage and is called “5-Lion-Face only.art”.

From the Relief tab, select Load Relief, pick “5-Lion-Mane.art”, hit Open, check Merging Highest and hit OK

The relief will look like the image shown below. This part is saved and is called “5-Lion-Unsmoothed.art”.

At this stage the basic shapes are completed and the model is ready for sculpting.



The file will now be smoothed and smudged with the sculpting tools to finish it off.

From the Model tab select Greyscale from Relief Select yellow as the primary colour From the Relief Editing tab select the Sculpting Tool icon Check Sculpt excluding colour from the Colour Usage area of the menu

Using the Smudge tool set to Diameter 50, Strength 50, Smoothness 100 and smudge in the areas shown in cyan above and in the direction of the blue arrows from the face to the mane

Smudge the eyebrows with a Diameter of 50 and Strength of 60 Smudge the top of the nose with a Diameter of 100 and Strength of 50

The model should end up looking like the image below



Set the Sculpting tool to Smooth, Diameter 50, Strength 50, Smoothness 0

Smooth the areas shown in the image below in blue with a single pass Smooth the green area with 3 or 4 passes with the cursor Smooth the pink area with 6 or 7 passes with the cursor

Once finished that smoothing operation, check Ignore under Colour Usage and Smooth the small holes each side of the head and at the top of the mane, smooth any other areas that you feel need it

The finished model is shown below left. This is saved as “5-Lion-Basic-Sculpt.art”. The sculpting is an iterative process and as much or as little can as is wanted can be done to finish the model. It can be used as it is or much heavier sculpting could be carried out if you wanted to give it more of your own look. This concludes this project and the Advanced Modelling section of the User Group documentation.


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