Build RTB objects for XPacker using Sketchup

[les_neilson]

I've worked out a pretty easy way to generate 3D, texture mapped assets for Race Track Builder XPacker, using nothing more complicated than the basic modelling tools in Sketchup, and a paint package that can generate .dds files. It avoids complicated UV unwrapping etc, and potentially can be used to build fairly complex structures. I should probably think about making a video tutorial, but I've never done one, so I'll explain it as best I can.

I've spent a while trying to figure out texture mapping without success... I'm the sort of lazy person who'll expend huge amounts of energy trying to find an easier way to do something rather than roll my sleeves up and study... anyway...

Step 1: You need to make a texture sheet that contains all the textures you'll need to cover the object. The sheet must be a square, and a power-of-two size (512x512 or 1024x1024 for example). All the individual textures should be the same relative size (to make things easier). You need good, square-on images of the object, front, back, sides. This is really the most important step, and the one to spend the most time over. The quality of the final result depends most of all on how good your texture sheet is.

Step 2: Take measurements of the object. If it's a building, you can use Google Earth to make a rough estimate. Looking at the texture sheet, estimate its real world dimensions (for example, I have the front and one side of a house on my sheet. I've estimated the front is 8m, the side is 5m and there's a bit spare, so my sheet is around 15m)

Step 3: Start up Sketchup and draw a rectangle on the ground. Make it the required dimensions (my example house is 8m by 5m). Use the extrude tool to make it into a box. The height isn't too important; you can adjust it as necessary. Basically, you're going to paint on the texture to the front, back and sides, then sculpt the shape to what you need.

Step 4: Create a new material. Don't bother to give it a name (you're only going to use one) Select Use Texture Image, and select your texture sheet. Enter the dimensions in the box. Now select the paint bucket tool and click on one of the faces. Part of the texture sheet should now be visible on the face. Right click on the face and select Texture -> Position. You can now move the texture sheet over the face until the right bit is located (just click and drag). There is also a tool for rescaling the image if needed. Do the same for the other sides. You can use the extrude tool now to adjust the height of the box to match the texture.

Step 5: In my example of a house, the upper part of the front of the house shows the roof. To make the roof, I'm going to draw a line where the roof starts and just fold it into the middle. Right click on the face, and select Texture -> Projected. Draw a line where the roof starts. Draw a line down the top centre of the box. Select the top line of the front face, and use the Move tool to push it into the middle. The angled section should now have the roof texture stretched to fit.

Step 6: Windows and doors can be drawn on and pushed in or pulled out as needed. They'll keep that part of the texture attached. If you make a porch, or any large extrusion, the stretched edge of the texture won't look good. Right click on the face, and de-select Texture -> Projected. The select Texture -> Position and find a part of the texture sheet to fit it.

Step 7: Save the model, then select Export -> 3D Model. Select .fbx format. De-select Export Texture Maps, but leave the other defaults.

Step 8: Convert the texture sheet to .dds format. I use paint.net. DXT1 format seems to work okay

Step 9: Create an XPack and load the fbx model and the dds texture sheet. And you're done!

[CTA_Racer]

thx a lot

[ArchangelX]

I just want to say thank you for this post...I used it to help develop objects for my concept track...Circuit Hawaii Concept on racedepartment

It was so useful...I'm now using this to create more tracks and I sincerely appreciate the help this provided.

[RTB]

Thanks - that description seems great. I've not had the time to play with Sketchup for years but this sounds like you are having some success! Well done!

[jonattan]

I´ve created a xpack with some signs, but they look fuzzy... any ideas?

with camera movement they look fuzzy, when playing they don´t look clear... I can´t upload a picture here.

[les_neilson]

Sounds like a texture resolution problem... What size are the .dds files, and what physical size are the signs? If you see them close up the textures need to be a reasonable size

[David F]

I think the problem in Sketchup is the UV Mapping, Dont have much options for edit the UV but is an easy tool for make xpacks