CODEWITHSUNDEEP
autodesk-forgeautodesk-viewer
Md. Shohag Mia
Md. Shohag Mia

Reputation: 374

Why viewer.select(dbids) makes the viewer slow and hide some part of the selected item(s)?

If I select some items of the model using-

viewer.select(dbids, viewer.model, Autodesk.Viewing.SelectionType.OVERLAYED)

and then try to zoom in/out or rotate the model, the viewer gets slower. But if I select some items using mouse click it doesn't affect the viewer at all.

If I select items using-

viewer.select(dbids, viewer.model, Autodesk.Viewing.SelectionType.REGULAR)

the viewer first hides everything except the selected items and a moment later shows up. It also hide some parts of the selected item(s). The navigation is smooth now.

This is before selection- Before selecting the items

This is after selection- After selecting the items

Is there any way to overcome this slowness and the hidden parts issue.

Upvotes: 0

Views: 312

Answers (1)

Petr Broz
Petr Broz

Reputation: 9934

Let me first explain the difference between the overlaid and regular selection highlighting:

Overlaid highlighting means that the selected objects are rendered twice. Once with their standard material, and once with the overlay material (so that they can be seen through obstacles as well). Of course, this doubled rendering may have significant impact on performance, especially if you select many objects (for example, by selecting a group of a large number of objects in the model browser).

Regular highlighting was introduced to mitigate the performance problems. In this case, instead of rendering the selected objects twice, they're simply rendered once, with a specific color tint applied to their regular materials. The drawback of this approach is that the selected objects are not visible through obstacles.

Now, to your problem: "regular" selection highlight is definitely the right way to go if the "overlay" highlighting is slow, but the fact that parts of your model disappear is strange. I'm thinking there might be a problem with the model itself. Perhaps it's too granular or tessellated (has too many parts or triangles), so applying the "selection tint" to all the selected parts takes unusually long time. Could you please try both the "overlay" and the "regular" selection with another type of 3D model? If it works well, you may need to look at the settings of the application that's creating this problematic model, and see if you can decrease the tessellation levels.

Upvotes: 1

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