What is the Decal Uploader?
The Decal Uploader is a feature that allows user-created decals (stickers) to be uploaded on the 'Community' section of gran-turismo.com, so they can be used within the Livery Editor in-game.
The decal file must be in SVG format and no larger than 15kb in size. By using the SVG format, it's possible to create high precision decals of very small file size.
What is an SVG file?
Image data used on computers can come as Bitmap data (BMP) or Vector data (SVG). Images in SVG file format can be enlarged or reduced in size without any loss of image quality.
The difference between Bitmap data and Vector data
The BMP format generates an image using groups of dots. If this type of data is enlarged, the small dots will start to be stretched, making edges of curves jagged or blurred.
On the other hand, the SVG format converts images to numbers when storing them. The advantage of vector data is that even if an image is enlarged, the image quality will not deteriorate, and the data size will not increase either.
The diagram below shows a comparison between an enlarged BMP file (left) and an enlarged SVG file (right). On the SVG file, the sharpness of the edges is maintained.
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Bitmap data
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Vector data
How to create high precision SVG files
An SVG file generating a picture can have very different levels of precision depending on how it is created. If an SVG file is generated using an auto trace feature of an editing software based on a Bitmap image (which consists of a collection of dots with no structure), often times it will generate a low precision SVG file with many unnecessary anchor points.
A standard SVG file consists of a minimum number of anchor points and path data. When creating a User Decal, make sure to use a high precision SVG file like this:
Comparison between efficient data and inefficient data
Let’s take a look at a comparison of two SVG files generating the same image.
On the right there's an SVG file that was generated automatically based on a Bitmap image (a collection of dots with no structure) and using an auto trace feature of an editing software. Since the image has low precision, small details have not been recreated correctly. Additionally, the file size is also large.
On the left there's an industry standard SVG file created by manually editing vector data of a Bézier curve: not only it's of high precision, but because of this the file size is also small.
SVG File Specifications
SVG files to be used as User Decals must adhere to the following specifications:
- the file must not be larger than 15kb in size;
- the text must be outlined;
- special drawing (blend) modes such as 'multiply' and 'adding' are not allowed;
- the file must comply to the SVG 1.0 or 1.1 specifications;
- for gradations, only simple shapes are supported;
Please note that the area displayed in a thumbnail is dependent on the SVG view port settings.