Hello. I want to draw to a material a simple circle based on the position of my laser pointer.
What I tried to do is get the Location of the Impact Point of the laser to the mesh and send that to the material.
In the material I just calculate the distance between the Impact point and the Pixel Position in World space.
I don’t seem to get the drawing on the left down side. Its rendering ok on the top right side.
I need the 3D position because I Want to draw on 3d objects not just planes.
Hey there @bogdanus! I’m no materials master, but I’ve brought some resources that might help out!
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SKM:
and one for static meshes:
In general, you don’t “draw into materials” in Unreal.
For the simple case of “show a laser pointer dot,” then a Decal Actor will work just fine. Figure out where the impact point is, and what the impact orientation is, and place a Decal Actor there. Make the Decal be the laser pointer image you want. (You may have to rotate the actor 90 degrees if I remember correctly, because “forward” is X, but “impact normal” is Z, IIRC.)
If you need procedurally generated texture content, then usually the best option is to create a RenderTarget asset, and then tie that to a Texture, that you bind to a Material (or Material Instance.) Then use a Camera to render to that RenderTarget whatever sub-scene you need rendered. (Which can include UMG widgets using a 3D Widget actor.)
Thanks for the answers. Really useful information.
