Knife Project

Willkommen in der Transport Fever Community

Welcome to the fan community of Transport Fever and Train Fever, the economic simulators of Urban Games. The community is free for you to share and inform yourself about the game. We cultivate a friendly and objective interaction with each other and our team will be happy to answer any questions you may have.


Registration and use is of course free for you.


We wish you a lot of fun and hope for active participation.

The Team of the Transport-Fever Community

  • Eine Erklärung einer eventuell wenig bekannten, aber hochgradig nützlichen Funktion im Blender. An introduction into a possibly little known but highly useful function in Blender.


    Many users of Blender will know the situation. There comes the time in the construction of most models when windows have to be cut into a building, a vehicle needs doors, an aircraft needs cockpit windows, and so on. Now, this can of course be done in many ways. Moving around vertices and lines or using the freehand knife usually leads to less than precise results and consequently to the utterance of non-gentlemanly language on occasion. But there is a way around this.

    Try "Project Knife". Let us assume that the wing of this An-24 here needs a chunk bitten out of it.

    In order to do so, we enter the Object mode and add another part to the model. This part will be the cutting template and will have Blender cut along its edges. Precisely. Of course, the circle here is just an example; it is absolutely possible to use highly complex shapes as well if so desired.

    Now we need to tell Blender that this circle is the template to cut along and that the wing is the part to be cut. This is rather simple: first mark the circle, then with Shift pressed, select the wing. Everyone has seen this already: now the circle is the orange reference part and the wing is marked yellow.

    So we can now proceed to enter the Edit mode. Unmark all the parts of the object to be cut, then click "Knife Project". Blender will now project the template on its recipient along the line of sight and slice it precisely where the projection meets it. It will either cut only the surface or all the way through, depending on whether "Cut through" is activated or not.

    Also note how the parts within the limits of the template become marked by Blender automatically. You can now use them as you see fit. Delete them, move them about, or by pressing "P" declare them an object of their own - the choice is yours. Of course, the cuts will leave wounds in the model; closing them up should be trivial.

    This method has another distinct advantage. If you have already unwrapped and textured the model before knifing it, the cuts will also show on the UV map and it will not be warped or distorted: the textures will stay where they were on the parts and not be altered in any way. However, expect weird results if you unwrap the parts again after the cutting is done.