BetterSpace: Whitestar Tutorial

Lesson 7 part c:
Patching it all up

In this final part of lesson 7, we will undergo the mammoth task of patching all of the curves that define the bridge section, which we built in lesson 7 pt A.

Rather than explain every patch in detail, I will use the system which I used in the previous step for patching, where I will give you a table describing which curves to grab and in which order, and the number of perpendicular and parallel knots to use. I will also now name each patch so that we can refer back to them.

When necessary, I will explain things that need further explanation.

So to it!

the goal of this lesson

When you are patching a large and complex model, it can quickly become confusing as to what patch fits where, and it is easy to lose sight of the underlying structure when all you have is a mass of polygons.

In order to avoid this, I patch my models in stripes, which use temporary surfaces, which allow me to quickly identify and select problem areas. You can see these stripes at work in some of the earlier images in the Whitestar v4.0 preview.

patching 'stripes' in action

You will see the convenience of editing and revising that this approach offers later in this lesson.

Let's start by patching the some of the easier areas. Follow the instructions in the following table:

Just so you don't whizz off doing all the curves without knowing what you should now be looking at, this image shows what you should have just created.

patch a1 created

If this is what you've got, then carry on, but if not, did you use the correct curves? The curves are all named in Lesson 7a, so refer back to that if you need to.

Once you have something like the image above, do not deselect anything or cut out the faces, move straight on to the next part.

Onward now, as we continue to patch stripe a.

Rather than deselecting everything and then fighting to reselect the curves, only deselect curve 4 from each step in the table, then select curve 4 from the next step and patch the quad formed by this.

As an example of this, I will talk you through making patches a1, a2 and a3.

You should have the curves r1, r4, pu5 and e2 already selected, and the patch that they form already created, as we did that in the previous step. Now carefully deselect curve pu5 by clicking on it, and then hold down SHIFT and carefully select curve e2. Patch this area with 5 perpendicular and 4 parallel knots, then carefully deselect curve e1 and then SHIFT-Select curve pu4 and patch the area with 5 perpendicular and 5 parallel knots.

This is the system which we will use for the whole of the patching process, so get used to it, as it will speed the way you work considerably. The table below shows the necessary details to patch the whole of stripe a, but remember that we have just created a1, a2 and a3, so don't patch them again.

Hopefully you will be left with this.

stripe a done

Assuming that this is what you are looking at, deselect everything but remain in Polygon Selection mode.

selecting with the polygons statistics window

Press W to display Polygon Statistics and click the button next to Faces as show below.

This will select all of the newly created polygons, but leave the curves behind.

Cut these polygons out, and place them into a new layer. Put the layer containing the curves into the background so that you are looking at this:

curves in background layer

Throughout this lesson, DO NOT MERGE POINTS unless I tell you to, as this will make editing later much easier.

Press Q and assign these polygons the following surface:

Now press the apostrophe key (the one above the TAB key and to the left of 1 on your keyboard) to swap the layer order.

I'm assuming that you're now looking at the layer with the curves in it, with the polygons in the background layer, much like this:

curves in foreground layer

We can now continue to build the next stripe.

Now use the Polygon Statistics window to select only the new faces.

If you followed this correctly, and didn't get too distracted by b2 not existing, you will have something like this:

stripe b complete

It should be clear now that you have built this stripe why b2 does not exist. If we made patch b2, it would actually be invisible once we had patched the extensions of the sides of the bridge (defined by the extension rails e1-e4) and if it were present, it would cause horrible rendering errors in that area.

Press Q and assign these polygons the following surface.

Now Cut these polygons out, swap the layers with the apostrophe key and Paste them back.

Temporarily turn on OpenGL and you should be looking at this:

openGL view

Return to wireframe preview mode and swap the layers back.

The next stripe will complete the main section of the bridge, leaving us to deal with the more tricky extensions.

Use the following table to create stripe c.

Once finished, select these polygons using the Statistics window and assign them the Temp Colour 1 surface, then cut them out and place them in the layer with the rest of the polygons.

stripes a, b & c completed

You may remember from lesson 7a that there was a hole at the front of the bridge which we need to fix. We will do this now.

the hole

If you zoom in closeley to the front of the mesh, you will see this hole

Now select patches a6, b6 and c6, and hide all the others by pressing + on the keyboard.

plugging the hole

The image above shows the points which need to be selected to fill this hole, and the polygon which you will create with them. Select the points from the bottom and work upwards to avoid having to flip the polygon afterwards.

To prevent the stripes a b and c being connected at this time by this new polygon, select it and cut it out, then paste it right back again.

Your hole should now be fixed.

The time had to come eventually, and here it is. We will now patch the extensions.

We will start at the base, where the extensions join the neck of the bridge. The table below will show you how. Remember not to deselect all the curves inbetween each patching operation.

If all went well, you should have a stripe of patches running down the length of the extension.

stripe d

Select the polygons and apply the surface Temp Colour 2 to them, then cut them out and paste them into the layer with the rest of the patches.

stripes a-d

You've got this, right?

While we're dealing with those long extension curves, let's patch the bottom of the extension. Same rules apply.

The results of this are shown below.

stripe e

Cut out those polygons and paste them into the other layer.

That stripe doesn't look quite complete yet does it? And for that matter, neither does stripe d.

To finish them off we need to patch around the bridge supports. Use the table below.

After you have moved the new polygons into the other layer, you will be left with this:

stripes e & d completed

(This image shows two views, as you can't see the top when you can see the bottom and vice-versa.)

We will now patch along the sides of the extensions to make them solid. This gets a bit fiddly...

When these patches are made, apply the surface Temp Colour 1 to them and move them into the other layer.

Now for the other side:

Cut these polygons out and paste them into the other layer, which should now look like this:

We will now patch the rest of the supports before finishing-off with the wing section.

These two patches don't really form a stripe, but it's convenient to name them as a group, so I've called them stripe h.

The image below shows these patches in place.

So now the whole thing is patched with the exception of the hole on the outer edge of the support, from whence the wing will protrude.

People often ask me what I think is the most critical piece of hardware when it comes to modelling objects like these. They usually expect me to say 'the processor' or 'the graphics card', but I usually surprise them with my response.

I would say that the processor is of minimal importance, unless you're working on a really high detail model (which the Whitestar, with its paltry 20,000-30,000 polygons, most certainly is not). Neither is it the graphics card, because whilst a speedy OpenGL display is superb to work with (and once you've had one, you can never go back), it's not really essential. I built the first version of the Whitestar on my Amiga, with its pathetic 14MHz 68020 processor and 32 colour display, and it was fine... well, almost.

My recommendation for the piece of hardware that will help the most with this kind of modelling is the monitor. I've been through them all, from working on the TV screen with my Amiga 500, through a 14" goldfish bowl with my A4000, a 15" beast with my P133, to a 17" monster with my dual P200MMX. From struggling with a resolution of 640x480 on the Amiga, to struggling to see a 1024x768 display on the 15", there's just never been enough screen. Well now there is. I'm sitting here dictating this (through IBM Viavoice 98: buy it!) and watching the text appear on my lovely 21" mammoth. Now I can comfortably run a screen resolution of 1600x1200, and let me tell you, Lightwave has never been better. I don't have to zoom-in to see small curves and select individual points, and I can see individual polygons on the Whitestar, rather than a big grey mass. It's sped up my work massively.

So there you are, forget shelling out for that Xeon processor or the Oxygen GMX card, just get a big monitor. Of course, if you can have the Xeon, the GMX and the huge monitor... nice isn't it!

Hmm, I went off on that one because I remember trying to patch this section with an 800x600 display, and it was hell. Hopefully you won't have the same problems.

We'll start with the top of the wing, and curl around to the bottom.

Notice that this stripe is broken in the middle, but this will be remedied by stripe j which we will create in the next step.

Move these polygons into the polygons layer and compare your result with this:

And now for the last stripe before the patching process for this lesson is completed.

This stripe is the painfully thin strip of polygons around the edge of the wing section.

Apply the surface Temp Colour 2 to these polygons, cut them out and paste them into the other layer.

Your completed mesh should look like this (image altered to show mesh)

patching complete

Save this object as ws_bridge_non-merged.lwo

Now we can put together all the pieces from lesson 7.

Load the object ws_bridge_bulge.lwo into a new layer. This will add the surface information from this object to our list of available surfaces.

Return to the layer that contains the object we've been building throughout this lesson and, whilst in polygon selection mode, draw a rough selection across the base of the supports as shown below. Don't worry if your selection isn't exactly the same as mine.

a rough selection

Now press ] (close square bracket) on your keyboard to select all connected polygons.

connected polygons selected

Hopefully, this has selected the patches e5, d7, h1 and h2. If it hasn't, select them manually.

Press Q to bring up the surfaces panel and apply a new surface with these settings:

This surface is called WS Underside because the surface used on these supports is identical to the one used on the underside of the lower hull, which we will construct in a later lesson.

Use the Mirror tool to mirror the whole object across the X-axis.

object mirrored in X-axis

Change to the layer containing the object ws_bridge_bulge.lwo and move it into the same layer as ws_bridge_non-merged.lwo.

ws_bridge_bulge pasted into layer

Make sure you are in Polygon selection mode and press W to access the Statistics window.

Press the next to Faces to deselect any polygons that are currently selected, then choose Temp Colour 1 from the pop-up menu.

Press the next to With Surface to select all polygons with the surface Temp Colour 1

Now select Temp Colour 2 from the pop-up and press the next to With Surface again in order to select all polygons with the Temp Colour 2 surface.

polygons selected using Statistics window

Now press Q to open the Surfaces window and choose the surface WS Bridge Skin from the list. Apply this surface to the selected polygons.

Deselect all polygons, change your preview type to Solid and carefully inspect your model to ensure that there are no problems with the mesh.

If you find none, you can now press M to merge all points and then Ctrl+T to triple all polygons.

oh, the joys of a 1600 x 1200 display...

You should now save this object as ws_bridge_assembly.lwo.

If this lesson went without a hitch for you, Well done! I'm actually expecting a flood of emails to tell me that I've described a particular patch in the wrong order, or used the wrong curves. If you discover such an error, please tell me about it, letting me know the lesson number and step number that the error occurs in. You can reach me by email at kier@ap3d.com.

Hmm, so much for just putting together a series of tables for this lesson. I think it's got as many screen-grabs on it as any of the other lessons. Oh well.

There will now be a brief interlude before the next lesson... phew.

Do you have any comments of questions regarding this lesson?