Ah, okay, thanks for the explanation! Is there a better solution to progressively revealing (or hiding) an object? I guess something like MRI slices, but being able to keep the "slices" on one side of the "beam" visible and the others hidden? That's probably not terribly clear, either! Thanks again!

Hi there,

I'm attaching a scene to help illustrate what I'm talking about:

I have some objects being progressively hidden (and, in other contexts, revealed) through animated Booleans. Those work as expected, but for some reason, if I enable Motion Blur, at (repeatable) frames, the objects "cut" by the Booleans suddenly lose their assigned material -- and in some cases, even if they're not impacted by the Boolean animating on a particular frame.

To see what I mean, with motion blur enabled, render the attached scene at frame 788. Advance one frame to 789. In 788, you will most likely see a blue material on the smaller cylindrical bits that march along a spline wrap; in 789, those cylinders will have lost their material, as well the red thin editable object above one of the white cubes (you'll see what I mean in the scene!). And on frame 790, things are back as they should be.

Then disable motion blur and re-render frame 789. The materials should render properly.

What is going on that motion blur has this effect on certain objects, but only at certain times? I tried messing with the objects used as "cutters" (either tweaking their size values or number of subdivisions), but I can't come up with a true solution. Is there something I'm missing?

Just in case it's helpful to know: I'm not married to the Boolean idea: I just want a way to hide (or reveal) objects over time. I thought about fields and vertex maps, but my limited understanding suggests I'd have to significantly increase object resolution for that to work...somehow. I'm happy to be educated! Thanks for looking!

Regards,
Blake

Edit: Okay, I can't seem to upload my scene: I just get a message that says "ERROR" with no explanatory text or anything. I placed the file on Dropbox here:

https://www.dropbox.com/scl/fi/vvi0b44mz13owr0yraqqp/S03E04-seq-01D_boole_test-02.c4d?rlkey=n4yo5lqzbzv6j89p9wt9b39it&st=1azjv96q&dl=0

Hello there. The post title might be vague, but hopefully the following description is less so:

I have objects (meshes) that should only be seen if there's a different object (a "lens" with a transmissive glass material) between it and the camera. That works as it should. What I want to know (and can't figure out) is if there's a way to enable/disable other flags based on a hierarchy of conditions; specifically, I'd like to disable reflections IF AND ONLY IF an object is NOT visible through the aforementioned "lens." Right now I can only seem to enable/disable reflectivity regardless of other conditions: there seems to be no way to create a "cascade," maybe, of prerequisite conditions.

I'm just now experimenting with the compositing tag, so maybe what I described above is possible and I just don't know it. I'd appreciate any advice! Thank you!

I'm attaching two images: in "A," you can see the reflection on the central box but not the object casting the reflection: this is where I'd like to be able to disable the reflection because the object is not behind the lens; in "B," you can see the object (through the lens as well as its reflection. I'm trying to hide the reflection from image "A" while still being able to see it in image "B."

Hello.

I have a group of objects functioning as one object that I'm trying to reveal over time. I tried using Booleans -- one big, encompassing Boolean to intersect the group, but it simply doesn't work. I don't see any errors, I just don't see the effect of the Boolean. And after that, I have no idea what to try next.

My grouped (compound) object is mostly cubes, although there is a Boolean in there which contains a cloner (and there's another cloner, too), so I assume my compound object is just too complex for the Boolean to handle.

Is there a way to accomplish what I'm trying to do? I thought about some kind of animated field or something, then realized I don't know where to begin or if that's even feasible. Thanks for any advice!

Regards,
Blake

Thank you so much for your constant help! I'm sure it's incredibly obvious, but I'm still learning my way through C4D. Believe it or not, I'm trying to figure things out on my own as best I can, but there are some things that I just don't know how to frame properly to know where to look. Aligning the workplane to an edge works perfectly, so again, thanks!

Hi there. I'm trying to use the knife tool to cut perpendicular to an existing edge when I begin the cut at that edge. Right now, the only thing I can manage is snapping perpendicular to the secondary edge; that is, the edge at which my cut would terminate. Is there any way to reverse this behavior? I'm attaching a marked up screen shot. I imagine this is probably extremely simple and I'm just not thinking about it properly!

I'm going to have to take a closer look at that! I am terrible with math, but I love learning how to use it for stuff like this, so I'm going to study that project file you attached. Thank you!

Yeah, that's just about it -- it's close enough to help me accomplish what I'm trying to do, so thank you! More specifically though, let's say there are four polys that share a central point: those polys all have slightly different normals because of how they were created as part of a sphere. Is there any way to get, say, the average of the polys' normal to use as the placement orientation? What I had to do was cut the polys, paste them back, flatten their scale on the local z axis to effectively give myself the averaged normal, then place the cylinder, then paste back the original polys and weld them back as part of the original sphere. That works, but if there's a better way accomplish that goal, I'm all ears! Thanks for the response!

Hi there. This is probably a super basic question, and I'm not even sure if I'm framing it properly, but I have an object with some polygons aimed at an arbitrary axis. I have another object that I want to align/orient perpendicular to those polygons, but I'm not sure how to do that.

Let's say I want to put a bolt head on an arbitrary point on an overall spherical shape: how would I ensure that the bolt head is perpendicular to the normal direction of the point (or poly) on which I wish to place it? Thank you!

Maxon support suggests that I'd need a separate simulation scene for each pyro output in order to render correctly. If that's true, is there any way to link different simulation scenes to that the outputs can interact? Meaning, I wouldn't want smoke from scene A not to mix with smoke from scene B, for example.

Thank you for your help. I'll check support and see what's going on there. I'll also do another test with various pyro volumes with white color and attempt to color through the scatter property and let you know what I find. Thanks again!

Edit: Still getting the weird blending effect by just using scatter colors in each volume. I've opened a support ticket, so we'll see if they have any better information. Thanks again!

Hi there. I've been struggling with this question for a while now, and hopefully someone here can help me wrap my brain around it! If I have a scene with multiple Pyro emitters, and if I create multiple Pyro Outputs (because of Scatter or Absorption differences, e.g.), every Pyro emitter acquires a blend of properties from however many Pyro Outputs there are. If I have, say, an emitter with color enabled and set to green, and if I have the color input in a Pyro volume mapped to color, I get what I expect. However, if I add another Pyro Output and assign it a different Pyro Volume (let's say this one has Scatter set to 1 whereas the other had it set to 4), my rendered output will look like both volume materials are fighting for jurisdiction over a given emitted volume. I'll attach some images.

What I can't figure out is if there's a way to restrict a particular emitted volume to receive material (Pyro Volume) effects from a specific Pyro Output. I'm probably not explaining it very well. I'll attach a scene example as well.

Thanks for any help!

[Edit: I didn't include the cache for the simulation, but it's small enough and should be simple to cache.]

pyro_outputs_test_01.c4d

Hey that works great! Thanks for the reply!

I'm far from knowledgeable, but I downloaded your file and messed around with it, and on the Step effector, under Parameter > Transform, I changed Transform Mode to Remap, and the direction of the scale reversed. I'm not sure how/where to tweak the results of the Remap, but maybe that's a place to pick up?

Hi there. I set up a simple spline emitter with its emission set to Shot: it's a long story, but all the complicated junk I tried to use fields for what I was trying to do didn't work, so I just used multiple emitters set to "Shot," but I was wondering: there's only the option to enter a single frame on which the shot occurs. Is there any way to use, say, an array of frames, meaning if I wanted to emit a burst on frame 30, and then another on frame 40, I could re-use the same emitter? Or do I just need to use multiple emitters? (Pulse isn't what I'm looking for, I don't think, since there's no periodicity to what I want to do.) Thanks for reading!