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1998 Nissan R390 GT1 Road Car

Apr 23, 2011, 05:48 (This post was last modified: Apr 23, 2011 20:31 by El1iP3S01D.)
Post: #1
1998 Nissan R390 GT1 Road Car
Folks, Can you help me put my car's wheel in the middle of the Yokohama tire?

So that i can map my wheels with it's rims colors and tires as well.





This is what i mean[Image: 0167.jpg].

Soon i will have a Lamborghini Insecta in Metallic Pale-face Green...
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Apr 23, 2011, 16:24
Post: #2
RE: 1998 Nissan R390 GT1 Road Car
yes ofnuts is correct... Can you help me?

Soon i will have a Lamborghini Insecta in Metallic Pale-face Green...
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Apr 25, 2011, 00:35
Post: #3
RE: 1998 Nissan R390 GT1 Road Car
Okay, I'm going to jump in here and give this a shot. There's probably about a dozen different ways to do this... I make no guarantees that this is the best way, or the easiest way, but it should work.

Start off by opening the image of the tire. First, we want to make sure that there is an alpha channel for transparency. In the layer dialog, select the layer with the tire (its probably the only one at this point) then right click and choose Add Alpha Channel. If its grayed out then you already have an alpha channel so no problem.

Next choose the Ellipse Select Tool (the circle one). Make sure Antialiasing is checked, Expand from center is checked, and Fixed is checked and set to Aspect Ratio. Just below where it says Aspect ratio it should have the ratio of 1:1. If it doesn't then type that in. Now click as close as you can to the center of the tire and drag out to the edge. You should now have a perfectly round selection that is pretty close to being around the outer edge of the tire's tread. You can fine tune the selection by moving the mouse cursor into the middle of the selection (but don't click) and then use the arrow keys on the keyboard to move the whole selection up, down, left, or right by one pixel at a time. Moving the mouse out to near the edge of the selection and then using the arrow keys will grow or shrink the selection one pixel at a time. Work like this until you're satisfied that your selection is as close as possible to the outer edge of the tire all the way around. Now, from the menu click on Select > Invert and then hit the Del key. Everything outside the tire should now be the checkerboard pattern indicating that it is transparent. Finally, click on Select > None.

Next you want to do the same thing again, only this time go from the center to the inner edge of the bead on the tire. Adjust the selection again, and when you're happy with it, hit Del. No need to invert the selection this time. Everything inside the tire should now also be the checkerboard pattern.

Okay, next we want to increase the canvas size to give ourselves a little elbow room. I'm not sure what size your images of the tire and wheel actually are, its hard to tell from the screen shot. I'm working with the tiny little images that I cut out of the screen shot, so you may need to adjust the size you use in this step. The main thing is that you want to choose a big enough size so you can import the wheel into a corner of the image and work on it without interferring with the tire we already did. Go to the menu and click on Image > Canvas Size. I used 500 x 500, but whatever size you need is fine. Too big is not a problem, that'll get fixed later anyway. Make sure you click on the Center button in the offset area, so the tire image will stay in the center of the new canvas.

Now we want to bring the picture of the wheel in so we can work on it. From the menu click on File > Open as Layers... and then select your wheel image. If it appears in the upper left corner, great... if not then choose the Move Tool (a four-way arrow), make sure the new layer with the wheel is selected, and drag it somewhere out of the way so its not on top of the tire. Next, you want to do the same thing to the wheel that we did with the tire. First, select the wheel layer in the layer dialog and right click, then choose Add Alpha Channel (again, it its grayed out don't worry about it). Then use the Ellipse Select Tool again and make a selection that is right around the outer edge of the wheel. Once the selection is the way you want it, invert the selection and then press Del, and finally click Select > None to dismiss the selection. Judging from your screen shot, it appears that the inner areas of the wheel, between the spokes, are already transparent so we don't have to mess with that.

Okay, we're almost there! The tire and the wheel are ready, we just need to put them together. Choose the Move Tool, and make sure the wheel layer is selected. Click on the wheel and drag it over to the tire. Don't worry about getting it exactly centered. Next, choose the Alignment Tool (a square with an arrow on each side). Select "Image" in the Relative to: box, and then select the wheel layer in the layer dialog. You then want to click on the two buttons in the center of the top two rows in the Align toolbox. The tooltips for these say "Align center of target", and "Align middle of target". Next, select the tire layer and click the same two buttons. This should align both layers exactly in the center of the image, and of course exactly centered with each other.

Congratulations, you just mounted a tire! And no skinned knuckles or gouged up alloy either! Just a little clean up left to do. Right click on the layer dialog and choose "Merge Visible Layers". And, since we no longer need all that extra space, on the menu click on Image > Autocrop Image. This should crop the image down to right at the edge of the tire (now you see why it didn't matter how big you made the canvas earlier). If you want more space around the tire, just use the Crop tool instead of the Autocrop to manually cut it down to whatever size you like. Lastly, you'll want to save this as a PNG file to preserve the transparency.
   

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Apr 25, 2011, 15:05 (This post was last modified: Apr 25, 2011 15:48 by El1iP3S01D.)
Post: #4
RE: 1998 Nissan R390 GT1 Road Car
Virago, you can't crop around the Yokohama tire because the crop part goes around the 3d tire i'm mapping it with; The crop goes to the rest of the tire on my 3d model....

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Apr 25, 2011, 18:32
Post: #5
RE: 1998 Nissan R390 GT1 Road Car
Okay, that shouldn't be a problem. Open the image of the wheel and do as outlined above to make everything outside the rim transparent, cropping it down right to the outer edge of the rim isn't a bad idea but isn't totally necessary either. Save it as a PNG. Close that and open the tire image. Clear out the inner part of the tire, but leave the outside alone. Now Open the new wheel image as a new layer and position it in the middle of the tire. Merge visible layers and save as a PNG. Voila, one sorta square looking tire!

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