Camera as texture projector?

[davidvonbehr]

Hello everyone,

is it possible to use camera texture projection with Blender/Octane. I haven't found a clue that it's possible but it seems to be working with C4D (according to the manual).

Maybe is there a workaround or a tweak? Would be very helpful.

Thanks
David

[ChrisH]

AFAIK there's no "pure Octane" way to do this (like the Camera Texture Coordinates in Cycles), but there's still two ways to accomplish it:

1. Using the UV Project Modifier in Blender, with the camera as projector. This works reasonably well, but might distort the texture some (especially if your mesh density is low [just testing with a normal cube and it looks distorted, after adding subdivisions it looks a lot better]). It uses and overwrites your UV map.
2. Using OSL projection: This OSL script works well (the first one): viewtopic.php?f=21&t=65575 This is probably the way to go.

(I haven't checked the Octane C4D manual, but when I did a quick search I could only find ways to do it using C4D tools [like UV Projection] and nothing specific to Octane).

[davidvonbehr]

Hi Chris,

thanks a lot for your help!

Gonna try it out now.

Best,
David

[linograndiotoy]

Hello everyone,

is it possible to use camera texture projection with Blender/Octane. I haven't found a clue that it's possible but it seems to be working with C4D (according to the manual).

Maybe is there a workaround or a tweak? Would be very helpful.

Thanks
David

Camera Projection is going to be available in the next upcoming Octane for Blender build, as a new option in the Image node.

[Whispermode]

Hello everyone,

is it possible to use camera texture projection with Blender/Octane. I haven't found a clue that it's possible but it seems to be working with C4D (according to the manual).

Maybe is there a workaround or a tweak? Would be very helpful.

Thanks
David

Camera Projection is going to be available in the next upcoming Octane for Blender build, as a new option in the Image node.

Hi Lino, all.

What's the application here? How will it differ from, say, 'project from view' in the UV menu?

[ChrisH]

How will it differ from, say, 'project from view' in the UV menu?

It's practically the same, but camera projection always follows the current camera, so if you move the camera you won't need to redo/adjust the UV, and thus matches the camera view in an animation (whether the camera moves or the object).

[Whispermode]

How will it differ from, say, 'project from view' in the UV menu?

It's practically the same, but camera projection always follows the current camera, so if you move the camera you won't need to redo/adjust the UV, and thus matches the camera view in an animation (whether the camera moves or the object).

Thanks, Chris - I'm still not 100% on this (my fault, not yours).

I use UV projection exhaustively, sometimes with image sequences, and in animation with camera moves. So it all moves how I need it to, within reason, so no need to adjust UVs.

What would be an example (if you have a minute to explain)?

[linograndiotoy]

The big difference is that has nothing to do with the UVs.

Let's say you have a backplate with a defined camera angle. After positioning the camera to so match the perspective of the shot, you can simply model some meshes an place them in the scene.
Then you can simply activate the Camera Mapped option (it will probably be renamed "Front Projection").

You can watch this video of a quick test I just made:

https://youtu.be/aBKjf6hUi0M

It's very similar to what you can do with the Project From View option in Blender, but you don't need to create any UV for your meshes.

[Whispermode]

The big difference is that has nothing to do with the UVs.

Let's say you have a backplate with a defined camera angle. After positioning the camera to so match the perspective of the shot, you can simply model some meshes an place them in the scene.
Then you can simply activate the Camera Mapped option (it will probably be renamed "Front Projection").

You can watch this video of a quick test I just made:

https://youtu.be/aBKjf6hUi0M

It's very similar to what you can do with the Project From View option in Blender, but you don't need to create any UV for your meshes.

OK, cool - thanks.

So the projection takes place at the point of activation and then sticks? I ask because, I've tested the OSL version I've seen in Chris's link above, but the texture slides about on the geometry whenever you move the camera... like it's projecting constantly. I'm probably doing something wrong.

The most obvious benefit I can see from your example is that you can project to non-subdivided geometry. When you 'project from view', you have to subdivide, sometimes to 5 levels to remove the distortion... so that's great!

What would be really useful is to accompany this with a calibration tool like BLAM. Any plans, Lino?

[linograndiotoy]

OK, cool - thanks.

You're welcome!

So the projection takes place at the point of activation and then sticks? I ask because, I've tested the OSL version I've seen in Chris's link above, but the texture slides about on the geometry whenever you move the camera... like it's projecting constantly. I'm probably doing something wrong.

Yes, it's recording the current state as you activate the option. Then you can move the camera as you need, no sliding!

The most obvious benefit I can see from your example is that you can project to non-subdivided geometry. When you 'project from view', you have to subdivide, sometimes to 5 levels to remove the distortion... so that's great!

What would be really useful is to accompany this with a calibration tool like BLAM. Any plans, Lino?

Well, we can use Blam or fSpy already!

https://fspy.io/