We currently use the model derivatives API to upload 3D models and later visualize them in a browser with the Autodesk Viewer v7 (previously Forge Viewer).
For different reasons we have been trying to hide and show parts of the model, but to do so in some cases we need to be able to hide geometric pieces of some elements while still being able to see the rest. For example if we had an element in gray (see image below) we would like to make the part of the element in red transparent.
I have looked into the Viewer API docs and there are functions that allow showing and hiding complete elements, but not cutting elements along a custom path.
While the docs mention the overlay functionality which enables us to add custom geometries by interacting with the THREE library that the Viewer runs on, drawing a copy of the whole model seems inefficient and prone to giving bad results.
Searching in SO I found that the THREE v71 library (which is the version the Viewer uses) has the possibility of occluding elements with the colorWrite option. See these links for reference:
three.js transparent object occlusion
Occlusion of real-world objects using three.js
I tried implementing something similar by using the colorWrite key when creating a new Three Material in an overlay, but nothing happens. This makes me think that either the Autodesk Viewer overwrites the render order (which makes sense) or openly ignores the colorWrite option. Does anyone know why and if there is a workaround for this? Or does anyone know if there is another way to cut an element that I'm not considering?
Please note that we have to do this with multiple elements at the same time and that reuploading the model periodically is not an option for us.
I got the following feedback:
The approach linked in the SO thread doesn't work, because we ignore both the colorWrite material property and the renderOrder mesh property. I also think that the approach would not work as expected in general, because using an invisible object to occlude a part of another object would always be view-dependent, and also occlude other objects in the background (so it wouldn't just 'cut out' a part of a single object).
Generally, this is not really a use-case for LMV, because it's a viewing tool, not a solid modelling tool.
Cut planes might help to get some of what you want, but they also have limitations:
It's possible to define multiple section planes to construct a 'shape' (that's also what the section box does internally). But since they are infinite, you wouldn't be able to cut away parts of one object, but not other objects (or other parts of the same object that intersect the cutplane). They're also designed to be 'outward' facing. The section box, for example, can only be used to narrow the scene down to some elements of interest. It's not possible to do the opposite, i.e. cut out some inner part of the design and keep everything around it.
This is what the section box could offer:
Related
Is it possible to export a view as more than 1 image? in any kind of split.
When exporting the view as an Image I want to keep the scaling consistent and Revit will not allow export an image with more than 15000 pixels. So on big Models I want to split the image to keep the meter per pixel consistent.
Any other suggestions are welcome.
I am not aware of any such possibility.
Please be aware of the following rule of thumb:
In general, if a feature is not available in the Revit product manually through the user interface, then the Revit API will not provide it either.
You should therefore research the optimal workflow and best practices to address your task at hand manually through the Revit user interface first.
To do so, please discuss and analyse it with an experienced application engineer, product usage expert, or product support.
Once you have got that part sorted out, it is time to step up into the programming environment.
I hope this clarifies.
I was able to do it by cropping different parts of the view and hiding everything outside the crop before the export. As the image export only export the visible elements.
I've encountered a different issue now, there are different visible objects outside of the actual model that interfere with the image export, sometimes those are elevation markers, site internal origin, other hidden annotations and many more.
Is there a way to hide absolutely everything outside the crop? do I need to go over every instance of a list of possible visible objects and hide them?
Thank you for sharing your solution to the original question on exporting several images displaying different elements by toggling their visibilities.
Regarding your second, new, question, on interfering elements such as 'elevation markers, site internal origin, other hidden annotations and many more':
Yes, indeed, I would suggest hiding those as well, just as you successfully handled the other 'standard' BIM elements, e.g., using the HideElements method, HideElementsTemporary, or, maybe better still for such special element types, hiding their entire categories using HideCategoriesTemporary.
I am brand new to Forge and making my way through some documentation but it seems quite hard to get some of the older examples working (pages don't load correctly etc) and I am currently using version 6, which seems newer than many examples too.
Is it possible in client-side code to take in some user data and generate a heatmap (overlayed ontop of the floor of a house) based on that data (i.e. different blocks of colour, it can be quite rudimentary).
This is using a Revvitt model uploaded to Forge and shown in the Viewer.
I have no experience with Three.JS but if anyone could point me in the right direction, show me a working example, or at least tell me if its possible I would greatly appreciate it!
There are a couple of options, with different levels of complexity:
You could use the official viewer APIs such as setThemingColor and clearThemingColors to add a semi-transparent color tint to selected objects.
If you need to overlay scene elements with anything more sophisticated, you could replace their original material with a custom THREE.ShaderMaterial. Just be sure to follow the documentation of three.js version 71 which is used by Forge Viewer. The process of adding new materials to Forge Viewer, and assigning them to specific objects is explained in https://forge.autodesk.com/blog/forge-viewer-custom-shaders-part-1. The article is a bit old, but I think the relevant parts of it (mainly the createShaderMaterial and selectionHandler functions) can be reused.
I'm using ForgeViewer to display both IFC models and custom geometry (point clouds and meshes using THREE.js directly), and I'm using the Section tool to cut away parts of the model.
Is there anyway I can set the size of the planes in the UI. I want the arrows and planes to be centered around specific models making them easier to use. Also, it would be nice to be able to set the default size and position of the cutting box.
The size of the cutting plane/box as well as the position of the manipulating gizmo are estimated by the section tool based on the bounding box of all visible objects. There's no UI to change that behavior, but you might be able to reverse engineer the official Section tool and perhaps modify it to your needs.
Edit: alternatively, you could retrieve the THREE.js geometry representing the cutting plane after it's been created by the Section tool (and placed into viewer.impl.sceneAfter) and customize it as needed.
Adding to Petr's answer...
Use the 'box section' tool (see screenshot) and manually adjust the box size by clicking on each of the box faces to adjust.
Then use Augusto's blog post (below) to programmatically capture (using viewer.getState();) and replay your box section (viewer.setCutPlanes(planes);).
https://forge.autodesk.com/blog/viewer-setcutplanes
I would like to face a problem for which I haven't seen a solution looking around in Internet. This is: I need to save the elements drawn by WEB users on a canvas space not as a flat image, but each one singularly. This in order to let the same user, or even other users, to modify every single element (drag-and-drop, erase, erase partially, ecc.) in a second moment. This should also help to eventually save a drawing history and restore it in next working sessions. All the examples I found were intended to save just a canvas flat image.
Update:
To better clarify: not necessary as layers, but for sure I thought to realize several different driving tools; a drawing element is the singular application/istance of a tool: a circle, a box, a added image, a straight line or even a free hand drawing that start from the moment of right button mouse click till it is released. Then the chance to save the elements state allowing to modify each one in a second moment.
You can't do this natively with canvas. You should look at using a third party library. Fabric is a library that was built to do what you want.
The base idea was to use convans as a container for vectorial shapes (triangles, squares, cirlces, etc.), manual drawn figures (see example http://www.williammalone.com/articles/create-html5-canvas-javascript-drawing-app/) and inserted images giving the chance to users to save/upload the content not as serialized image, but with each distinguished element in its original format in order to continue to work on them in a future work session.
I'm creating a space game in actionscript/flex 3 (flash). The world is infinitely big, because there are no maps. For this to work I need to dynamically (programatically) render the background, which has to look like open space.
To make the world feel real and to make certain places look different than others, I must be able to add filters such as colour differences and maybe even a misty kind of transformation - these would then be randomly added and changed.
The player is able to "scroll" the "map" by flying to the sides of the screen, so that a certain part of the world is only visible at once but the player is able to go anywhere. The scrolling works by moving all objects except for the player in the opposite direction, making it look like it was the player that moved into that direction. The background also needs to be moved, but has to be different on the new discovered terrain (dynamically created).
Now my question is how I would do something like this, what kind of things do I need to use and how do I implement them? Performance also needs to be taken into account, as many more objects will be in the game.
You should only have views for objects that are within the visible area. You might want to use a quad tree for that.
The background should maybe be composed of a set of tiles, that you can repeat more or less randomly (do you really need a background, actually? wouldn't having some particles be enough?). Use the same technique here you use for the objects.
So in the end, you wind up having a model for objects and tiles or particles (that you would generate in the beginning). This way, you will only add a few floats (you can achieve additional performance, if you do not calculate positions of objects, that are FAR away. The quad tree should help you with that, but I think this shouldn't be necessary) If an object having a view leaves the stage, free the view, and use the quad tree to check, if new objects appear.
If you use a lot of objects/particles, consider using an object pool. If objects only move, and are not rotated/scaled, consider using DisplayObject::cacheAsBitmap.