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How to stamp a single picture with an alpha in texturing

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I'm in the process of modeling a little town with simple models (because it will be seen from far) but I would like to add some detail by kind of stamping some texture-details on the models, such as doors and windows. These doors and windows I got by cutting them off from the original photos. So I would like to use them as kind of elements or modules to build the final texture of the models.

I know that I could use the photos as materials, but in this case I would need to place and scale the material correctly over the model. Even if I would use the polygon-mode (to paint faster) the sorrounding walls of the e.g. windows would be seen and would interfere with the wall-color of the building. So in this case I would need to use an alpha mask so that only the window would be painted.

To make a brush seemed to be the solution, but when I tried it (in stamp-mode and default-color switched off) it was very unsharp and pale.

Is there another methode or maybe some settings?

I'm using version 3.5.19A

Thank you!

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The picture explains one way of doing what you are asking. It is not completely liked you asked but gets the job done also

The reason for not reducing the size of your photo in 3DCoat is the resizing in 3DCoat is not resampling.

Resampling the photo in another program will keep the detail as much a possible in the resampling process. I had resampled my window down to 82 x 116 to fit the scale of my model and to go with the 1024 x1024 texture map.

Once you have loaded your photo in 3DCoat and stamped it to the model, you can just keep moving and stamping the same image...

Test this on some object to see how everthing works and I hope this helps.

I need to put in a feature request to be able to load a png file or a PSD file with a alpha channel using the transform / copy tool.

You can also use place image along the spline tool, it does support png files with an alpha channel but is more cumbersome to use.

Edit: see the post below, as I found some more helpful information for you. I really need to take some more time to explore or refresh my memory on some of 3DCoats tool sets...


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I explored this tool more... I do not use it all the time...

I found that when you stamp your first image you can use one of the spline tools to grab the part of the stamped image you want while still using the transform copy tool.

Now the unwanted areas are cut away and you can stamp this image.

(I stamp the first image on a separate layer then delete that layer when I am done)

Edit: Once you place several images, then select them and your work goes faster... The transform and copy tool also captures your height details from your model.

In the picture with the round window, I had added some bump to the window to push out the round window part. Now when I stamp these not only is the image stamp but the depth is stamped as well.

Edit : Save your edited images as a rect file under the save option in the dialog box to be able to reuse them

Edit : You can use your default 2D paint editor (preferences) to edit the image without closing down 3DCoat. I had to go to my windows machine to test this feature...

A couple of examples... There are quickly done so the quality is not that great but they are just to show the effects...




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Wow, digman, that's great!

Thank you very much for this detailed kind of tutorial!

I tried the version with copy/transform and then selcting the wanted area with the spline-settings of the brush. It works perfect with straight lines, not so good (picture is unsharp - maybe recalculated different) with the kind of bezier-splines. But that's okay, I can life with it. The whole procedure seems to be a not wanted side-effect ;-) A little bit complicated - but it works.

Of course it would be great to import png-files with an alpha-channel by the copy/transform tool.

Thank you again, this was a great help for me!

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Glad it helped

If I did not make it clear, you can edit your image (getting rid of unwanted parts before stamping) in your default 2d editor (preference settings / external editor). The paint program has to support layered PSD files.

click the edit button in the transform/copy tool dialog box...

You will get a little degrading of your image when stamping, how much depends upon your uv map texture size and the amount of pixel space that the uv island occupys you are stamping it too Also remember do not resize your image smaller in 3DCoat.

When your resampling your image in another program, the image always loses some crispness, use the sharpening feature in your program to get some of it back..

Linear texture filtering (view menu) is on by default, this also slightly blurs the image...

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Thank you again, digman!

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