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I need to change the texture of a plane in a 3D scene. In the BackEnd class in C++ I make a new QImage for setting it on a texture. I want to send it as a signal to my QML and there assign it to the planes material property.

But it looks like TextureMaterial etc. can only use a URL path to a texture file. I cant't save my Images to my hard drive to use them as a URL path. It will be too long. I need to change my texture 20+ times in a second and there are other things which this program should to do in the same time.

Is there any way to do this?

Eddy Alleman
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Stakan Stakan
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1 Answers1

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You can have a look at my implementation of a background image in Qt3D.

The way I achieved what you are looking for is by using the classes QTextureMaterial, QTexture2D and QPaintedTextureImage. I had to flip the image before drawing it that's why I subclassed QPaintedTextureImage but this might also just be what you need. Instead of loading the texture from disk, like I did, you could set the QImage on your subclass as an attribute. You only need to make the C++ class available to QML and set it on your plane (maybe you could even use PaintedTextureImage directly and write the image painting in their JavaScript-style language).

You can add your QPaintedTextureIage to the QTexture2D and then set the result as the texture on the QTextureMaterial. I'm not sure if this yields the best performance, though.

You could also try to follow these steps but they seem to be a bit more involved. This would mean you have to implement your own version of QAbstractTextureImage and return the appropriate QTextureImageDataGeneratorPtr. You can checkout the sources to gain a better understanding.

Florian Blume
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